Document Rp21y8wj5v5xYdGv7ZY0771N8

United States Gypsum THE GREATEST NAME IN BUILDING Red Book BB013 0170 BB013 0170 United States Gypsum Red Book of Lathing & Plastering TRADEMARKS: Ttia tollavifl| tfadamarfci ira awoad and/or rofisttrod in tha U.S. Patant Oftwa Or Umtao Sutaa Grown Canpanr, and art uaad throu|ftout tRia Oook to dasifntta particular oioducts manulacturad Or that comoaar: USG imout product*, planar. fypsum csraooarot. fiOar board a. adftanrasi: STRUCTO-UTE. STRUCTO* BASE. STfeuCTO-GAUGE. OIAMONO. ORIENTAL. IVORY. CHAMPION. STAR. HI<LITE. AUOtCOTt (olanarmf product)): PYROBAR itypsum partition Mai: ROCKLATH (plaa* tar oasai: MORTASEAL(maaon'slima): BRlDiOINT. 8RACETITE. TRUS*LOK (latfimi sntanrn: TRUSSTEEL (matal nudS);~R0 TOP 'planar. planar Oasa. partition tiia coma*!): FIRECOOE (planar, piaatar basal; GRANO PRIZE (lima, paint); TEXOUTE. ACREPOX. PRO-KYOtpaints); rHERMAFI8R(iniuiaun| wool I: SHtTROCK(fypum aiiboard, ranlrant cnannai. uaiant); PRf*A*TAPL DURABONO (|oiat traaunant); IMPERIAL (paint piaatar. planar oasa. ratnforctnc Upa. sat catalyst). 0 m 2T W C*J* f I > ' Bed Book j at Ladling j vRaslerng T i This Red Book is a guide to good lathing and plastering procedures and describes the newest developments in the plastering field--including the time-saving, lower cost methods now booming in popularity. Versatile and dependable, lath and plaster construction meets the wide range of building requirements including durability and strength, fire resistance and sound isola tion. Lath and plaster are not only ideal finishing mate rials for conventional wall and ceiling surfaces, but their flexibility also suits them to ornamental contours--the only interior finish that can be readily adapted to such design. In addition to descriptions of plaster systems and their installation, this book contains new data on products, methods of application and performance ratings. It is designed to serve not only the experienced contractor and journeyman, architect and dealer, but the novice who wishes to better understand plastering, its advantages and applications. The United States Gypsum Red Book, like the company's plastering products, sets the standard of the industry. 8B013 0173 Table of Contents page chapter Good Lathing and Plastering Practices 7 1 Vonoor Products and Application 29 2 00 Standard Products and Application 57 Systems and Performance Oata 107 4 Special Applications and Tools 18S 5 Job Problems and Remedies 209 6 How to Inspect a Plaster Job 7.227 a -------- o - U O N| 'U CHAPTER IS Good Lathing ands Plastering Practices! chapter 1 paga What's Plastering Today? Advantages of Plastering Good Lathing Practices Framing Requirements Job Storage Mechanical Handling Temperature and Humidity Conditions General Application Recommendations lor Plaster Bases Reinforcing Isolation and Control Joints Floating Interior Angles Grounds Vapor Barriers Fastening Good Plastering Practices Basecoat Plasters Water Aggregates Setting Time Mixing Finish Plasters Drying Decorating Sound Control Requirements 9 10 11 11 12 13 13 14 16 16 17 18 19 20 20 21 22 22 23 24 24 26 26 27 BB013 0179 CHAPTER 1 Good Lathing and Plastering Practices WHAT'S PLASTERING TODAY? In the last few years plastering has broken its traditional bounds, met changing needs in construction and advanced to open up countless new opportunities. As a result of concen trated research and development, a whole new concept in products and systems is available to meet market needs. Today's plastering products include high-strength veneer plasters economically applied to large-area plaster base; hard, durable finish plasters for smooth, long-lasting walls and ceilings; special materials that won't deteriorate in strength or appearance for use with electric cable radiant heating; and modified conventional structural accessories, fasteners and trim that result in easier application and better performance. To meet the specialized needs in today's building design, products must be coordinated into systems that provide high performance at competitive costs. Today's systems offer added structural stability, excellent fire resistance and im proved sound isolation-one of the fastest growing require ments in modern building. United States Gypsum has long been the leader in developing high-performance products and systems for the plastering industry. At the U.S.G. Research Center, largest in the indus try, within recent months a series of dependable cost-saving f 10 GOOD PRACTICES: Advantages of Plastering systems has been developed to join the list of historic U.S.G. "firsts" which already included gypsum partition tile, gypsum lath, truss-design studs, acoustical and periited piasters, and double hydrated lime. Such improvements are released only after their superiority has been clearly proved by thorough testing and field trial. Manufacture of these products is to rigid specifications care fully controlled to insure consistently high-quality products for fine craftsmanship. Evidence of this is an overwhelming preference for USG's products at the marketplace. Success and growth in today's plastering depends on keeping job standards of quality and appearance high while cutting construction time and costs to a minimum. This handbook outlines United States Gypsum's new and time-proven prod ucts and systems; gives application information for good construction practices demanded of plastering today. ADVANTAGES OF PLASTERING FIRE RESISTANCE: gypsum plaster will not support combus tion. When attacked by fire, water of crystallization is rei leased and turns to steam which effectively retards the I spread of flame. Fire-resistance ratings of up to 4 hrs. are | available with specific partition, ceiling and fireproofing con structions. SOUND RESISTANCE: gypsum lath and plaster partitions have high resistance to sound transmission. Resilient attach ment of piaster base further improves sound ratings, makes partitions ideally suited as party walls. VERSATILITY: suitable as divider, corridor and party walls; pipe chase and vent shaft enclosures; acoustical and radiant heated ceilings; extenor walls and wall furring; membrane fireproofing. Adaptable for use in every type of new construc tion-commercial, institutional, industrial and residential-- and in modernization. Produces beautiful joint-free walls and ceilings whether m plane or free-flowing contoured surfaces. Easily adapts to most modules and dimensions. HIGH STRENGTH: lath and plaster surfaces resist cracking, have high structural integrity, are resistant to impact and scratching. FINISHES BEAUTIFULLY: plastering offers wide possibilities for finishing: smooth, monolithic-appearing trowelled surfaces that readily accept paint, wallpaper, vinyl coverings, or ceramic tile; beautifully random textured and floated sur faces ; machine-textured acoustically treated surfaces; decora tive exposed colored aggregated surfaces. BB013 0177 Framing Requirements: GOOD PRACTICES 11 LOW MAINTENANCE: the hard, smooth finish of plaster, par ticularly the new Imperial Plaster and Diamond Finish, is highly abrasion resistant and durable; makes the surface easy to keep clean and sanitary; can be attractively redeco rated many times. LIGHTWEIGHT: Pyrobak Partition Tile is 30% to 50% lighter than commonly used masonry. The new Imperial Plaster systems compare with the weight of conventional drywall. SPEEDY INSTALLATION: the new high-strength veneer plas tering is fast. Big 4 ft. wide base goes up quickly. Perfectly integrated components speed erection. Plasters mix fast, trowel on easily, set in less than l Vi hours ready for next-day decoration. UNIFORM QUALITY: factory made to rigid specifications, USG plastering products are carefully controlled to insure uni formity in results time after time. GOOD LATHING AND PLASTERING PRACTICES Two ingredients are required for a quality plaster job-- quality products and skilled craftsmen correctly employing good lathing and plastering practices. USG plaster bases, plasters and plastering accessories are top quality products designed to work together, job-proven and constantly im proved. But without proper planning and correct installation by the contractor, the products cannot be expected to produce the desired quality results. This section deals with the basic recommendations that should be followed in planning and completing the best pos sible job. These good lathing and plastering practices can give the contractor greater profit through fewer callbacks, less waste and lower job costs, and quality results that pro duce quicker sales, higher prestige and an enduring business reputation. FRAMING REQUIREMENTS The framing that will receive plaster bases should be thor oughly inspected to be certain that all previous work has been completed in good order. Good framing, particularly wood, is essential regardless of the type of wall surfacing materials used. Wood framing meeting the following minimum requirements is necessary for proper performance. --OB 1. Framework should meet the minimum requirements of JJJ FHA and local building codes. 2. Framing members should be straight, true, of uniform U dimension, and framing should be properly aligned. q 3. All framing lumber must be of the proper grade for the ^ OB .-------- 12 GOOD PRACTICES: Job Storage Joists must be aligned where necessary intended use, and 2"x4" nominal site or larger must bear the grade mark of a recognized inspection agency using grading rules for lumber recommended to American Lumber Stand ards Committee. 4. All framing lumber should have a moisture content not in excess of 15% at the time of gypsum base application. Use of kiln-dned lumber for joists is recommended. 5. Extremely hard (dense) or soft framing members should not be used for attachment of base. Failure to observe these minimum framing requirements, which are applicable to screw and nail attachment, will mate rially increase the possibility of fastener failure due to warp ing or dimensional changes. This is particularly true if framing lumber has greater than normal tendency to warp or shrink after erection. Framing should approach as closely as possible the moisture content it will reach in service by allowing the building, after it is enclosed, to stand as long as possible prior to the appli cation of the gypsum plaster base. JOB STORAGE Lath and plaster products should be ordered for delivery to the job the day before application. Materials stored on the job for longer periods are liable to damage and abuse. Rather than ship all plaster to the job at one time, fresh plaster should be sent to the job daily as needed. Plaster stored for long periods is subject to damage, variable mois ture conditions and aging that probably will produce varia tions in setting time and create performance problems. Plastering products must be stored inside in a dry location and away from heavy traffic areas. Stack plaster bags on planks or platforms away from damp floors and walls. Store gypsum plaster bases flat on a clean dry floor; vertical stor age may damage edges or deform board. Protect metal corner beads, casing beads and trim from being bent and damaged. BB013 0179 Handling/Conditions: GOOD PRACTICES 13 All materials used on the job should remain in their wrap pings or containers until ready for use. MECHANICAL HANDLING Completely mechanized on-site handling of plastering mate rials is one of the few remaining ways for contractors to lower prices in the face of today's rising costs. Time and money savings can be substantial when correct handling pro cedures are used. Job conditions vary so widely that it is impossible to establish universal materials handling proce dures. However, there is much to be learned from inspecting methods used in various job situations and from reviewing resulting costs. Case studies and step-by-step materials handling procedures used by contractors around the country have been made by U.S.G. Its products are packaged to provide low handling costs. Its experts will apply this accumulated experience and knowledge to contractor's on-site handling problems to help save money and submit a better bid. For more details on this personalized service, consult the local U.S.G. Sales Offices listed inside the back cover. TEMPERATURE AND HUMIDITY CONDITIONS In cold weather (outdoor temperatures less than 55*F.), the temperature of the building must be maintained in the uni form range of 55* to 70* F. both day and night for an ade quate period prior to the erection of gypsum plaster base, the application of plaster, while the plastering is being done, and after the plaster is dry. The heat should be well distributed in all areas, with deflection or protective screens used to prevent concentrated or irrjtguiar heat on plaster areas neai the source. Ventilation must be provided to properly dry the plaster dur ing and subsequent to its application. In glazed buildings, this should be accomplished by keeping windows open suffi ciently to provide air circulation; in enclosed areas lacking normal ventilation, provisions must be made to mechanically remove moisture-laden air. ib io Eioaa 14 GOOO PRACTICES: Plaster Bases GENERAL APPLICATION RECOMMENDATIONS FOR PLASTER BASES Plaster bases, those materials that receive the basecoat of plaster, may be classified as (1) gypsum or metal lath bases, or (2) masonry bases. These materials provide a level sur face for plastering and add reinforcement to the plaster. As such, they must be rigid enough to accept plaster and produce a secure bond between the plaster and the plaster base--both necessary to develop strength and resistance to abuse and cracking. Acceptable plaster bases provide either a suction, mechanical, or adhesive bond to secure the plaster to the base. In a suction bond the tiny, needle-like gypsum crystals, upon set ting, penetrate the surface of the base and weld the plaster to it. A mechanical bond occurs when plaster is pressed through holes in the base, forming keys and a secure bond. In an adhesive bond, a liquid bonding agent coats the masonry to form an adhesive surface to hold the finishing materials. To insure adequate rigidity of plaster constructions, recom mendations for the spacing of supports and fasteners must be strictly followed. Apply plaster bases to ceilings first and then to partitions, starting at the top and working down to the floor line. EXCEPTION: In application of Rocklath Base to Trussteel Studs begin application at the floor, (see Chapter 4 for details). Gypsum Lath ROCKLATH PLASTER BASE, a gypsum lath in sheet form, is an ideal high-suction rigid base for gypsum plasters. It should be applied face out with the long dimension across the supports and with end joints staggered between courses. Cut lath accurately so it slips easily into place without forcing and fits neatly around electrical outlets, openings, etc. All lath ends should bear on supports and be securely fastened. Install any lengthwise raw cut edges at bottom ground strip or wall-ceiling angle. Bridjoint B-l Clips should be used at end joints between supports. Apply Comente to all interior angles. Staple to the lath only. Metal Lath USG Metal Lath is an excellent base for plastering be cause the steel becomes embedded in plaster producing a reinforced plaster slab. It should be applied with the long dimension across the supports and with end joints staggered between courses. Apply Riblath with the rib against supports. Lap ends of metal lath 1' and sides at least H". Lap Riblath by nesting outside ribs. If end laps occur between supports, they should be laced or tied with 18-ga. tie wire. Secure lath BB013 O IB i Masonry Bases: GOOD PRACTICES 15 to all supports at intervals not exceeding 6'. At all interior angles, metal lath should be formed into the corners and earned out onto the abutting surface. Interior Masonry PYROBAR GYPSUM PARTITION TILE is specifically designed as a plaster base for intenor non-load bearing partitions and is used extensively for its light weight, low cost and outstanding fire resistance. Only gypsum plaster should be applied to Pyrobar since lime and Portland cement plaster do not bond adequately. For the same reason, only Ked Top Partition Tile Cement should be used for mortar (see Chapter 4 for installation details). CLAY TILE ANO BRICK are frequently used for plaster bases. Care should be taken to make sure that surfaces are suffi ciently porous to provide suction for the plaster and are scored for added mechanical bonding. Smooth-surfaced clay tile that is glazed or semi-glazed does not offer sufficient bond for plaster. CONCRETE BLOCK offers a satisfactory base for plaster that is relatively stable and strong. The surface of the units should be porous, for proper suction, or face-scored for ade quate mechanical bond. Units must be properly cured to min imize dimensional changes during and subsequent to plaster ing. MONOLITHIC CONCRETE ceilings, wails, beams and columns should have a complete and uniform application of a highquality bonding agent before plastering. This surface treat ment produces an adhesive bond suitable for the direct appli cation of gypsum plasters or gypsum gauged lime putty finish coats. Exterior Masonry Plastering direct to exterior masonry walls is not recom mended. Exterior walls are subject to water seepage and moisture condensation that may wet the plaster and damage interior decoration. BITUMINOUS WATERPROOFING COMPOUNDS also do not pro vide a good plaster base. Gypsum piasters should not be applied to surfaces treated with these compounds. FOAMED PLASTIC INSULATIONS have not proven to be ideal plaster bases for direct application of gypsum plaster be cause of foam plastic's low suction characteristics and low structural strength which may result in cracking of the plaster. However, some foamed insulation manufacturers have specific directions for application of foam when direct plas- BB013 O 16 GOOD PRACTICES: Reinforcing/Control Joints tering is to be used, as well as detailed specifications for plaster mixes and methods of application to be employed. While U.S.G. does not recommend direct application of plas ter to foamed plastic base, if this method is to be used we suggest adhering closely to the foamed plastic manufacturer's recommendations. REINFORCING Holes cut in a thin lath and plaster membrane, such as door frames, borrowed lights, etc., cause a concentration of stresses in the plaster, typically at intersection of head and jamb. The use of additional reinforcement (channels, runners, striplath, self-furring diamond mesh lath) is recommended at the weak ened area to distribute concentrated stresses. Wood or metal inserts used as reinforcing for cabinets and shelving on non-resilient surfaces should always be applied to the inside of the stud chord or flange to prevent breaking up the stress skin of the piaster. Heavy fixtures such as water closets and lavatories should be supported by separate carriers and not the lath and plaster surface (see Chapter 5 for details). ISOLATION AND CONTROL JOINTS Lath and plaster surfaces (non-load bearing) will not resist stresses imposed by structural movement and are subject to dimensional changes in temperature and humidity. It is recommended that lath and plaster surfaces be isolated from the following structural elements by Control Joints, Floating Interior Angles, or other means where: A BB013 0tB 3 Floating Angles: GOOD PRACTICES 17 a. a partition or ceiling abuts any structural elements, ex cept the floor, dissimilar wall or partition assembly, or other vertical penetration. b. the construction changes within the plane of the parti tion or ceiling. In long partition runs, control joints should be provided no more than 30 ft. o.c. Door frames extending from floor to ceiling may be used as control joints. For doors less than ceiling height, control joints extending from the center or both comers of the frame to the ceiling may be used. Expansive ceiling areas should have control joints, spaced not to exceed 60 ft. in either direction. The continuity of both lath and plaster should be broken under control joints. Con trol joints may be positioned to intersect light fixtures, heat ing vents, or diffusers, etc., which are already breaking ceiling continuity. FLOATING INTERIOR ANGLES The floating interior angle method of applying gypsum plaster bases should be used at all ceiling angles, particularly with radiant heat applications. This construction effectively reduces angle cracking caused by stresses at intersections of wails and ceilings. At the intersection, the first ceiling fastener should be spaced about 7* from the wall. Specified fastener spacing should be used in the remainder of the ceiling area. On the sidewalls, all gypsum plaster base must be applied to overlap and maintain firm contact at ceiling line in order to support the ceiling piaster base previously applied. Along the ceiling intersection, fasteners should be omitted adjacent to the ceiling angle. The first fastener should be nominally 8' from the ceiling intersection. RED TOP radiant heat plaster base ceiling application BB013 0184 IMPERIAL plaster base side wall application ROCKLATH plaster base side wall application IS GOOD PRACTICES: Grounds F 700 series v---y metal trim 1 ( j j grounds . V,' grounds - S'A\ ZT. /.V I700-A USG metal lath ROCKLATH Plaster Base- IPMlaPsEteRrIABaLse-nU^ -' 700-B USG Casing Beads (expanded or short flange) H hx" x'ZBIC____ #66 Square Edge ________ - 1/.' #4 or #138 Ouarter Round f- ix*:-- #60 SemiSquare Edge GROUNDS The thickness of conventional basecoat plaster is one of the most important elements of a good plaster job. To insure proper thickness, grounds should be properly set and fol lowed. Grounds may be defined as wooden strips, comer beads (plumbed and aligned), metal base screed, or metal casing beads applied at the perimeter of all openings and other locations. In addition to these, and especially on walls with no openings and on ceilings, plaster screeds should be installed to insure plumb and level surfaces. Plaster screeds are either dots or continuous strips of plaster applied to required ground thick ness to permit proper plumbing and leveling. Grounds should be set to obtain the following minimum plas ter thicknesses: 1. Over gypsum lath............................................................ H' 2. Over bnck, clay tile, gypsum block or other masonry........................................................................... 3. Over metal lath, measured from face of lath ... H ' 4. Over veneer plaster base, one coat.............................. Vie' 5. Over veneer plaster base, two coat.............................. BB013 O t0" Vapor Barriers: GOOD PRACTICES 19 VAPOR BARRIERS The condensation of moisture in exterior walls is a common cause of peeiing and other paint failure, warped siding, rotted studding and sills. Efficient vapor barrier installation in all extenor walls and ceilings of buildings constructed where freezing weather occurs for extended periods of time usually prevents this damage. A vapor barrier should be located on the warm side of exterior walls and top floor ceiling. Aluminum foil is one of the best vapor barriers known and used commercially. Bright aluminum foil is lami nated to the back of Insulating Rocklath and Imperial Plas ter Base to provide vapor barrier protection. ILLUSTRATION OF IMPORTANCE OF VAPOR BARRIER Inside Atmosphere 70F <5% 3.63 0.332 in. Hg Temperature Relative humidity Grains moisture per cu. It. Resultant vapor pressure Outside Atmosphere 10F 90% 0.69 0.057 in. Hg 20 GOOD PRACTICES: Fastening FASTENING Correct fastener selection and adherence to fastener spacing is extremely important to good plastering performance. This is particularly true in fire-rated construction where greater fastener spacing or use of improper fasteners will not offer sufficient structural strength and fire-resistance rating needed. Gypsum plaster bases are attached to framing with screws, nails, staples or special clips. Nails, screws and staples should be driven so that the fastener head or crown bears tightly against the base but does not cut the face paper. To prevent core fracturing, they should be driven at least H " away from ends and edges. Staples should be of flattened wire driven so the crown is parallel to wood framing. Screws should be used to attach gypsum plaster bases to U3G Metal Studs, Furring Channels or RC-1 Resilient Channels. Screw application of plaster base Rocklatk Plaster Base may also be applied to USG Metal Studs with MS-1 Clips. Metal lath should be attached to metal supports with tie wire (minimum 18 ga.) and to wood framing with fasteners engaging two strands or a rib and providing at least H ' penetration. For attaching cross furring channels to supports or main runners, use at least two strands of 16 ga. tie wire. For the exact type of fastener and spacing used in specific plastering systems, see Chapter 4. PLASTERS The base of all gypsum plasters is gypsum rock--hydrous calcium sulfate, which has a water content of about 20% in chemical combination. In manufacture, about ^ of this chemically combined water is removed from the gypsum rock by means of a controlled calcination process. Then water is added at the job, the material crystallizes (sets), reverting to its original chemical composition. BB013 01B7 Basecoat Plasters: GOOO PRACTICES 21 xS ^3 N. cPo, Gypsum rock n GYPSUM On drying, returns The Magic Mineral to original form that will not burn CfUShed and Ground . On wall, crystals form and harden Re-absorbs water when mixed on ioD Giant rotary calaner in wnich crushed gypsum is cooki Red Top Gypsum Plasters are specifically formulated to control setting time and other important characteristics. This depends upon the intended use and method of application, the climatic conditions of the area, and job conditions. USG Basecoat Plasters can be applied by using either hand or machine methods, on gypsum or metal lath: gypsum or clay tile; concrete or cinder blocks; brick, or other approved plaster bases. BASECOAT PLASTERS The architect's specifications and the plaster base will deter mine the plastering method, either two-coat or three-coat, to be used. TWO-COAT PLASTERING, often called scratch and double back, is generally accepted for piaster application over gypsum lath and masonry. The base (first) coat should be applied with sufficient material and pressure to form a good bond to the base and to cover well, and then be doubled back to bring the plaster out to grounds, straightened to a true surface with rod and darby without the use of additional water, and left rough to receive the finish (second) coat. THREE-COAT PLASTERING is required over metal lath and over edge-supported or perforated gypsum lath used in ceil ings. It is preferred for other bases because it develops a harder, stronger basecoat. The scratch (first) coat should be applied with sufficient material and pressure to form good BB013 018B 22 GOOD PRACTICES: Water/Aggregates full keys on metal lath, and a good bond on other bases, and then cross-raked. The brown (second) coat should be applied after the scratch (first) coat has set firm and hard, brought out to grounds and straightened to a true surface with rod and darby without the use of additional water, and left rough to receive the finish (third) coat. To obtain the full hardness, high strength and superior performance available in gypsum basecoat plasters, water, aggregates and setting time must be carefully controlled. In addition, proper mixing and drying of the plaster are required to obtain these superior functional characteristics. Factory prepared gypsum piasters such as the high-strength veneer plasters--Imperial and Red Top Radiant Heat Plaster --Red Top Wood Fiber Plaster and Structo-Lite Plaster are highly suited to provide trouble-free results on the job. Requir ing the addition of water only on the job, they conquer the drawbacks of job-aggregated plasters. WATER All gypsum plasters require the addition of water on the job. Water provides lubrication and workability to permit applica tion to the plaster base. It also induces the proper setting of gypsum. Water should be clean, fresh, suitable for domestic consump tion, and free from mineral and organic substances which affect the plaster set. Water which is used for rinsing or cleaning con tainers and tools should not be used, as it accelerates the plas ter set. Only enough water should be used to provide a plaster of workable consistency. Too much water in machine-applied plasters (in excess of 10% more than for hand applied mixes) or over-aggregated plasters will cause weak, soft walls and ceilings. Excessive water creates voids in the mass upon drying and reduces the piaster strength and hardness. AGGREGATES Aggregates are added to gypsum piasters to extend coverage, reduce shrinkage, and lower cost. Aggregates recommended are: (1) sand, which is denser, stronger and provides greater sound transmission loss than lightweight aggregates, and (2) perlite, a lightweight aggregate that generally offers better fire resistance, insulation values and reduced weight. For sand float finishes the aggregate should be a finely ground silica sand. Because of its low strength and slower drying properties, vermiculite is not recommended as an aggregate. All aggregates used should have proper gradation of size as outlined in ASTM C-3S. Improperly sizea aggregates will produce weak walls because there is insufficient plaster to bond the aggregate particles. Sand should be clean and free BBQ13 01B9 Setting Time: GOOD PRACTICES 23 USE OF AGGREGATES WITH GYPSUM PLASTERS Maximum Recommended Proportions Maximum Quantity of Aggregate, in Cu. Ft., To Be Used With 100 Lbs. of Neat Gypsum Plaster Plaster Base Gypsum Lam No. of Coats 3 Types of Coats scratch brown Under Smooth Trowel Finish Sand (1) Perlite 22 32 Under Other Finishes Sand (1) Perlite 22 33 2 basecoat 2Vj 2 I'h Metal Lath 3 scratch brown 2 3 --2 -3 2 2 2 Unit Masonry 3 scratch brown 3 3 33 33 3 3 2 basecoat 3 33 3 (11 Appro* S No. 2 uiovtis of sind cquil 1 cu. ft NOTES. In a construction srstom wnieft his morn inn as tho plislor oast, poritio aurogato is not reeammondod tor uso in (ho oisocoat {Mistor, unloss i host or acoustical finish is usod. In a smooth trowoi finish ovor a basocoat with partita a(gro|ato. add cu. ft ot fmo silica sand par 100 lbs. of gaugmi piasitf. or usa aggragatad gauging. of dirt, day and foreign matter that might affect the setting time of piaster. Perlite aggregated plasters should not be ma chine applied when vertical lift is over 30 ft. or hose length exceeds ISO ft. Over-aggregating or the use of excessively fine aggregate reduces the strength and hardness of plaster. The maximum recommended proportions for aggregates are shown in the table above. SETTING TIME The proper setting time for conventional basecoat plasters is generally from 2 to 4 hours after mixing, and this should be checked for close conformity on both the scratch coat and the brown coat operation. Normally, plaster shipped to the job will fall in this range. If conditions exist that affect normal setting time, retarders or accelerators are used. The danger of "quick set" plaster is that there will not be sufficient time to get the plaster from the mixer to the walls without retempering on the mortar board, and such reterapering will produce a piaster of lower than normal strength. The correction for "quick set" is to add the proper amount of re tarder in solution with water at the mixer. USG Retarder is less eificient in cold weather than in warm weather, and greater amounts are usually required to produce like results. If plaster does not set for 5 to 6 hours, no harm will be done to the resulting piaster surfaces, but a "slow set" of the plaster (generally one taking more than 6 hours) should be avoided by adding accelerator in a dry state at the mixer, as BB0I3 0190 24 GOOO PRACTICES: Mixing such plaster may be subject to a "dry out", particularly in hot, dry weather, and will have a lower than normal strength when finally set. Only USG Accelerator and USG Retarder should be used with USG Plasters. Other materials may not be compatible with USG Plaster, producing undesirable results. MIXING A mechanical mixer is preferred to box mixing, because it is easier to assure that the plaster aggregate and water are eveniy mixed. Keep the mixer continually clean--a most important precaution--because partially set material is a powerful accelerator. Mechanical mixing is mandatory with veneer plaster and Red Top Radiant Heat Plaster. When mixing by hand, plaster and sand first should be mixed dry to a uniform color in a mixing box. Then the water is added and the plaster hoed into the water immediately, and thoroughly mixed to a proper consistency. Proportioning is weight of gypsum to volume of aggregate. A No. 2 shovel used to add sand to the plaster mix generally carries 15 lbs., or approximately one-sixth of a cubic foot. Thus, a 100:1 mix would use 6 shovels of sand to 100 pounds of gypsum plaster, a 100:2 mix 12 to 13, and a 100:3 mix 18. to 19 shovels of sand. Perlite is generally packaged in bags containing 3 or 4 cu. ft. Thus, proportioning of the plaster mix can be easily worked out. Prepare only one hour's supply of plaster at one time and do not remix if plaster has started to set. All such plaster should be discarded. FINISH PLASTERS Finish coat plasters applied to basecoats provide the surface for final wall or ceiling decoration. The visible success of the job depends on the finish coat, and required measures should be taken to finish correctly. Finish coats should be applied only to properly prepared basecoats, except Imperial Finish that is applied only to Imperial Plaster Base. TROWEL FINISH COATS should be scratched in thoroughly and immediately doubled back to fill out to a smooth, dense surface for decoration, free of surface blemishes and irregu larities. Thickness should be Kg' to H*. Keenes Cement Finishes should be troweled until the material sets. BB013 019 Finish Rasters: GOOD PRACTICES 25 FLOAT FINISH COATS should be scratched in thoroughly and immediately doubled back to a true, even surface. Float, using a shingle, cork, wood, carpet or rubber float to bring aggregate to the surface to produce a finish of uniform texture free of slick spots, cat faces, and other blemishes. Use water sparingly in natural color, and use no water on colored finishes. With Oriental Exterior Stucco, no water should be used in floating or texturing; surface should be fog-sprayed with water for several days after setting. MACHINE-APPLIED SPRAY FINISHES should be uniformly ap plied to produce a texture approved by the architect. ACOUSTICAL PLASTERS should be applied in not less than two coats, to full xh ' grounds, following the manufacturer's direc tions. In the mixing and application of finish coats, U.S.G. recom mendations, as described in Chapter 3 and as printed on each bag, should be strictly followed. Other recommendations, out lined below should also be followed for satisfactory results. 1. Factory prepared finishes such as Diamond Finish, Imperial Plaster, Oriental Interior Finish and Exterior Stucco are ideally suitable as a finish coat. Requiring the addition of water only on the job, these finishes eliminate the need for job-mixing ingredients and time-consuming soaking. 2. A smooth trowel finish should not be used over lightweight aggregate gypsum basecoat applied over metal lath. A sand float finish or an acoustical plaster is recommended. 3. Where the gypsum basecoat is Strdcto-Lite or contains lightweight aggregate (perlite or vermiculite) and a smooth trowel finish is used, the finish coat should be Red Top Gauging Plaster and lime, with addition of % cu. ft. of perlite fines or 50 lbs. of No. 1 white silica sand per 100 lbs. gauging plaster or use Rs> Top "Quality" Gauging Plaster that is mill-aggregated. ' 4. Gypsum or lime base finishes, including Eeenes cement, should not be used directly over a Portland cement basecoat or over concrete block or other masonry surfaces. 3. Gauging plasters providing an extremely hard surface, such as Structo-Gauge and Eeenes cement, must not be used over Structo-Lite, or a basecoat with a lightweight aggregate. BB0I3 0192 6. Diamond Finish is not for use over lightweight aggregate gypsum basecoats. 7. Only gauging plasters should be used for gauging lime putty. Neat plasters should not be used. 26 GOOD PRACTICES: Drying/Decorating DRYING Proper drying of plastered surfaces is important to their ultimate performance. Rapid drying after the plaster has set is good because it produces high strength. Drying too fast before the plaster has set may leave insufficient water for the chemical reaction needed to properly set plaster. Slow drying should be avoided because it may cause "sweat out" and reduced strength. Proper ventilation should be provided to remove moisture-laden air. COMPLETION: at the completion of the finish plaster work, all plaster should be cleaned from beads, screeds, metal base and metal trim, leaving work ready for decoration by others. All plaster rubbish should be removed from the building, leaving floors broom clean. Excess material, scaffolding, tools and other equipment should be removed from the building and job site. DECORATING Quality plaster construction merits equally good decoration, and the wise plasterer will recommend paints that enhance the appearance of his finished job. For superior results, U.S.G. has specifically developed Texolite Primer-Sealer as a surface treatment over plaster. It is compatible with Grand Prize Latex Wall Paint, Texolite Alkyd Latex Paint, and other quality USG interior finishes. U.S.G. also manufactures a full line of texture finishes to meet the preference of every custom er. Refer to Chapter 3 for the Selector Guide to USG Paint Products. BB013 6193 Roller application Spray application Sound Control: GOOD PRACTICES 27 Good practices for decorating require that: 1. Ail surfaces must be dry, sound, clean, free of dust, grease or oil. 2. Paints should be delivered in original unopened containers and protected from damage and tampering. 3. All materials should be used according to instructions. SOUND CONTROL Where plaster construction is used as a sound barrier, a non-hardening caulking material should be used to seal all cutouts, such as at electrical, TV and telephone outlets. Caulking should also be used under door and ceiling runners to seal the voids between runner and structural slab. Seal by caulking around the perimeter of the construction and at all intersections with the adjoining structure. Avoid cutting holes back to back and adjacent to each other. Use sand aggregate only; do not use lightweight aggregates. Door and borrowed light openings are not recommended when the plaster partition is used as a party wall. CHAPTER 2 a | Veneer Products s ' and Application! 1 chapter 2 page Veneer Plaster Bases and Accessories Trim Accessories Structural Accessories Fasteners and Adhesives Veneer Plasters and Application Imperial Plasters Diamond Finish Plaster RED TOP Radiant Heat Plaster Application of Veneer Bases Joint Reinforcing Application Metal Accessories Application Structural Accessories Erection Application of Fasteners 31 33 35 36 38 38 42 43 45 50 51 52 54 CHAPTER 2 Veneer Products and Application As the unchallenged leader in the development of plastering products and systems, U.S.G. also ranks first in meeting the specialized needs of today's building design. Within recent years, U.S.G. has released a series of economical highstrength veneer Imperial Plaster systems and made a break through in piaster used in electric cable radiant heated ceilings. These new systems have received rapid acceptance because they meet today's demand for abrasive-resistant sur faces. lower cost, fire and sound-resistant construction. They are treated separately in this chapter since they represent a new concept in plastering. IMPERIAL Plaster Systems are leading the new trend to veneer plastering because of their inherent economy, speed of applica tion, and extremely hard surface durability that is obtainable with few other materials. Lower in cost than conventional plaster systems; Imperial Plaster Finish is applied in a onecoat operation permitting next-day decoration. IMPERIAL PLASTER Base 4 ft wide and in lengths up to 14 ft covers area quickly Radiant Heat Plaster Ceilings combine two new products specially fortified for use with electric heating cable--Rn> Top Radiant Heat Plaster and Plaster Base. The surface provides higher long-term resistance to heat deterioration tn 18 O Jj O J. I 32 VENEER PRODUCTS: Bases and permits faster, more uniform heat emission--yet the sys tem offers lower applied costs than other material combinations. In these systems large-sized gypsum piaster base is screwed or nailed to wood framing, metal studs or channels or adhesively applied to gypsum coreboard. Special glass fiber tape is stapled over joints before high-strength veneer plaster is applied. As the materials and installation methods used may be new to lathing and plastering, the following pages are devoted to a description of these products and their application. GYPSUM BASES IMPERIAL PLASTER BASE, PLAIN, is a special gypsum lath in large,sheet form that has been specifically engineered for use with Imperial Plasters. It provides the strength, absorption and troweling characteristics necessary for top quality veneer plastering performance. The large sheets minimize the number of joints and speed installation. The high-density, fire-resistant gypsum core has a superior controlled absorption paper lightly tinted blue on the face side and a strong gray liner paper on the back side. The face paper is folded around the long edges to reinforce and protect the core. Long edges are square; ends are cut square and finished smooth. Available in two thicknesses: H", for single-layer application in new residential construction; %recommended for the finest high-strength veneer plaster construction. The greater thickness provides increased resistance to fire ex posure and sound transmission and allows 24' o.c. spacing on wood framing. Width: 4'; lengths: 8', 9', 10', 12'; approx, weight: 1,970 lbs./MSF for H", 2,460 lbs./MSF for H". IMPERIAL PIASTER BASE TYPE X. made in *4" and thicknesses, combines all the advantages of Plain Imperial Plaster Base with additional resistance to fire exposure--the result of a specially formulated mineral core. Listed by U.L., Inc. under Label Service for certain fire-tested partition, floor ceiling and column constructions (see Chapter 4 for details). Width: 4'; lengths: 8', 9', 10', 12'; approx, weight: 2,025 ibs./MSF for H", 2,460 lbs./MSF for H". RED TOP RADIANT HEAT PIASTER BASE is a large-size gypsum lath used with Red Top Radiant Heat Plaster in electric cable ceilings. Developed after years of research and testing, this unique product provides the high structural strength and resistance to heat deterioration needed as a base for Red Top Radiant Heat Plaster. A special chemically fortified fire-resistant gypsum core gives the base excellent . resistance to heat deterioration and face paper delammstion .i at normal cable operating temperatures (135*F.). Highly absorbent blue paper is bonded to the face side of the fortified BB013 0198 Trim Accessories: VENEER PRODUCTS 33 core and is folded around the long edges. Strong gray liner paper is bonded to the core back. Long edges are square; ends are cut square and finished smooth. Red Top Radiant Heat Plaster Base is suitable for direct application to wood joists or metal furring channels and for resilient application to RC-1 Resilient Channels. Joints are reinforced with Imperial glass fiber tape before heating cable is attached. Available: H" or H" thickness in plain core, hi" thickness only in Type X core for fire-rated construction; lengths 8', 9', 10', 12'; approx, weight: 1,970 lbs./MSF for Vt" plain, 2,460 lbs./MSF for plain, 2,025 lbs./MSF for H" Type X. USG COREBOARD is a 1' thick solid gypsum board product to which additional layers of plaster base are laminated in the Solid and Double Solid Imperial Partitions. Thickness: 1"; width: 24"; edge: "V" T&G; length: 8', 9', 10' and 12'; approx, weight: 4,150 lbs./MSF; finish: gray paper, not suitable as an exposed surface or plaster base. SHEETROCK W/R GYPSUM WALLBOARD is a water-resistant large sheet form base for the adhesive application of ceramic, metal, and plastic tile. Used in lieu of Imperial Plaster Base in tub, shower and other high-moisture areas where tile is to be adhesively applied. It is water resistant all the way through: (1) multi-layered face and back paper is chemically treated to combat penetration of moisture; (2) the gypsum core is made water-resistant with a special asphalt composi tion. Easily recognized because of its distinctive green core and face. Raw cut edges and nail heads must be treated with SHEETROCK Brand W/R Sealant. Thickness: and width: 4'; length: 8' or 12'; approx, weight: 2,025 lbs./MSF; edges: tapered; finish: green treated face paper, suitable for receiving tile. Sealant available in 1-qt. cans, 6 qts. per carton. TRIM ACCESSORIES With today's plastering advancements comes the need for special-function accessories to produce economical, better, more beautiful walls and ceilings. U.S.G.'s concept of "pack age design'' has produced a separate line of comer beads, metal tnm, reinforcing and structural accessories designed specifically for high-strength veneer plastering. Use of these accessories gives the important advantage of dealing with a single manufacturer for all components of a wall or ceiling. USG CORNER BEADS are 26-ga. galvanized steel angle U reinforcement for external comers. Various sizes provide plaster protection, true and straight lines at comers and 2 grounds for plastering. a 34 VENEER PRODUCTS: Trim Accessories 800-A 300-8 700-A 700-B l_v/v r USG Control Joint r093 800-A CORNER BEAD provides for a plaster thickness up to hi". Used with Imperial Plaster in two-coat system applica tions. Length: 8'; weight: 136 lbs./MLF; packages: 60 pcs. per ctn. 800-8 CORNER BEAD gives hit" grounds for veneer Imperial Plaster in single-coat applications. Length: 8'; weight: 75 tbs-/MLF; packages: 125 pcs. per ctn. USG METAL TRIMS provide neat edge protection and offer a means for isolation at cased openings, at ceiling angles and at intersections where veneer plastenng abuts other materials. Made of 29-ga. galvanized steel, these tnms have perforated flanges to strengthen the plaster bond. They fit over H ' or hi ' Imperial Plaster Base and provide He' grounds for Imperial. Plaster. NO. 700-A is a channel-type casing nailed to door or window back. Sizes: hi" and hi"; length: 7', 10'; weight: 98 lbs./MLF for hi", 106 lbs./MLF for H"; packaged: 50 pcs. per ctn. NO. 700-8 is an angle edge trim used at junction of plaster base with rough concrete or masonry--attached by stapling when used with metal framing. Sizes: hi' and hi"; length: 10'; weight: 74 lbs./MLF for hi", 80 lbs-/MLF for H'; pack aged: 50 pcs. per ctn. USG CONTROL JOINT NO. 093 is designed to relieve expansion and contraction stresses in large areas of Imperial Plaster over Imperial Plaster Base. Made of roll-formed zinc to provide 3/32' ground dimension. An open slot, hi" wide and 7/16' deep, is protected with plastic tape which is removed after plastenng is completed. The short flanges are perforated for key-locking plaster and for stapling to plaster base. Used from floor to ceiling in long partition runs, and from door header to ceiling. Length: 8', 10'; weight: 112 lbs./MLF; packaged: 30 pcs. 8' or 25 pcs. 10' per ctn. oozo etoa Structural Accessories: VENEER PRODUCTS 35 IMPERIAL Tape IMPERIAL TAPE is a glass fiber lino-weave tape, 244' wide, used to conceal and reinforce joints of Imperial Plaster Base and Red Top Radiant Heat Plaster Base. Tape is attached with 94 " staples before veneer plaster is applied. Open weave of tape allows rapid air escape during piaster embedding. Usage: about 370 lin. ft. of tape per MSF of surface; pack aged: 12 rolls of 300 ft. ea. per ctn. STRUCTURAL ACCESSORIES USG METAL STUDS are non-load bearing channel type studs roll-formed from 25-ga. electro-galvanized steel. Cutouts at top and bottom of studs provide limited chaseways for pipe and conduit. The channel is designed for 16' stud spacing for large-size Imperial Plaster Base in USG Metal Stud Partition Systems. Also used in certain other plastering systems (see Chapter 4 for construction details). Packaged: 10 pcs. per bdl.; available as follows: Size No. 158 No. 212 No. 358 Width 1)4' 244' 344' Length 8'. 9' 8', 9', 10'. 12' 8'. 9'. 10', 12', 16' Wt. Ibs./MLF 340 430 510 USG METAL RUNNERS are roll-formed from 25-ga. electrogalvanized steel channel type sections designed to receive USG Metal Studs and to secure various types of USG partitions to floor and ceiling. Also used in rough framing door and borrowed light openings. Length: 12'; packaged 10 pcs. per bdl.; available as follows: Size No. 158 No. 212 No. 358 Width 144* 244' 344' Wt. Lbs./MLF 283 339 122 i : ; 1 36 VENEER PRODUCTS: Fasteners/Adhesives USG Metal Angle Runner USG METAL ANGLE RUNNERS are 1H "x % "x22-ga. eiectrogalvanized steel angle sections used to secure 1" coreooard at floor and ceiling in USG Solid and Double Solid Imperial Plaster Partitions. Length: 10'; weight: 176 lbs. per MLF; packaged: 10 pcs. per bdl. USG FURRING CHANNELS are roll-formed hat-shaped sections of 25 ga. electro-galvanized steel. Designed as ceiling and wall furring channels for screw attachment of Imperial Plaster Base. Also suitable fumng for Rocklatk Plaster Base and Red Top Radiant Heat Plaster Base. May be clip-attached to 1H 'main carrying channels with USG Furring Clip. Face width : 1*4"; furring depth: length: 12'; weight: 320 lbs. per MLF; packaged: 10 pcs. per bdl. RC-1 RESILIENT CHANNELS are 25 ga. electro-galvanized steel channels used for resilient attachment of Imperial and Red Top Radiant Heat Plaster Bases to wood framing. Widely used as one of the most effective, lowest-cost methods to improve sound transmission loss in partitions and ceilings of gardentype apartments, motels and other structures. Flange is pre punched 4" o.c. for screw fastening to framing with USG 1 'i " Screw Type W. Base is attached to channel with 1" Screw Type S. Channel is 2%" wide x '' in depth. Length: 12'; weight: 213 lbs. per MLF; packaged: 20 pcs. per bdl. USG CONTROL JOINT No. 75 and CASING BEAOS Nos. 60 and 66 are used with radiant heat plaster ceilings. For descriptions of these items, see Chapter 3. FASTENERS AND ADHESIVES USG SCREWS are the result of many years of development aimed at producing the best possible attachment of gypsum boards to steel, wood or gypsum supports simply and quickly. A complete line of 13 different special, self-drilling, self tapping steel screws has been made available to improve construction systems and simplify installation methods. Ail screws are highly corrosion resistant and have a Phillips head recess for easy installation with a special bit and powerdriven screwdriver. BB013 O202 y Fasteners/Adhesives: VENEER PRODUCTS 37 Imperial Plaster Base or Rn> Top Radiant Heat Plaster Base is fastened to steel framing1 with the Type S screw, to wood framing with the Type W screw. Type S screws have a patented drill point and special design theads that provide maximum holding power in steel studs, minimize thread stripping. Special Hi-Lo threads on Type G and Type W screws speed installation, provide excellent holding power in gypsum or the various woods used in framing. The special patented bugle head used when attaching gypsum bases spins the face paper into the cavity under the screw head and produces a uniform depression free of fuzz. Other head designs are available for the assembly of metal framing and installation of wood and metal trim. The ability of USG screws to pull the plaster base tightly to the framing without damaging the board has virtually eliminated loose board attachment and consequent problems of "fastener pops" in wood frame construction. Fewer screws than nails are generally required. Speed of installation compares favorably with nailing when electric screw guns (see Chapter 5) are used. An adjustable screw depth control assures uniformity of penetration, protects the face paper, minimizes core fracturing. Applications and types of USG Screws are shown below: 15 V TYPE S-12 pan head trim head TYPE G bugle head 1' TYPE S--BUGLE HEAD ' and single layer Imperial base to metal studs, metal furring channel or resilient channel: or Rd> Top Radiant Heat Plaster Base to metal furring or resilient channel. gj 1V4' TYPE S--BUGLE HEAD 1' gypsum coreboard to metal angle runner. O q 1-5/16' TYPE S--BUGLE HEAD 0 H' face layer to metal in double layer Imperial systems. M O 1%* TYPE S--BUGLE HEAD U H* face layer to metal in double layer Impbual systems. 38 VENEER PRODUCTS: Plasters 1%" TYPE S--BUGLE HEAD *4" face layer Imperial base through coreboard to metal angie runner. 2>/i" TYPE S--BUGLE HEAD *4 " face layer Imperial base through coreboard to metal angle runner. Va" TYPE S--PAN HEAO Metal studs to metal runners. TYPE S-12--PAN HEAO Metal studs to metal door frame (12 ga. max.). 1 s/b" TYPE S--TRIM HEAO Wood trim over single layer Imperial base to metal studs and runners. 2`/4" TYPE S--TRIM HEAD Wood trim over double layer Imperial base to metal studs and runners. 1V4" TYPE W--BUGLE HEAD 14' or 54" single layer Imperial or Radiant Heat bases to wood framing and RC-1 resilient channels to wood framing. IV," TYPE G--BUGLE HEAD Face-layer Imperial base to base-layer Imperial base or gypsum coreboard in laminated construction. Face-layer Imperial base to gypsum coreboard. USG ADHESIVES represent the latest advancement in the attachment of face-layer Imperial base to base-layer Imperial base or gypsum coreboard in double-layer laminated and USG Solid and Double Solid Imperial Partitions. Two adhesives are recommended, both dry powder products, applied by spreader; require job-mixing with water and temporary fastening with 114" Type G Screw; qualify for fire-rated construction. USG LAMINATING ADHESIVE provides excellent bond, levels minor misalignments. Available in 25-lb. bags. PERF-A-TAPE JOINT COMPOUNO (EMBEDDING TYPE! provides a tight bond, permits adjustment of boards after contact. Available in 25-lb. and 32-lb. bags. VENEER PLASTERS AND APPLICATION IMPERIAL Plasters These products lead the way to faster, more economical, better performing jobs in today's plastering. Applied to a thickness of only 1/16" to 3/32", these high-strength veneer plasters offer beautiful, hard (3.000 psi), abrasion-resistant surfaces that are ready for decoration the next day. Factoryprepared Imperial Plasters are easy to work, have stabilized set, offer excellent trowelability, high plasticity and outstand ing coverage. In applied cost they average only slightly above BB013 0204 Plasters: VENEER PRODUCTS 39 j, |Imperial^ Impend Impend ^psd^ ^ :h ^l conventional dry-wall. Systems using Imperial Plaster qualify for Are-resistance ratings up to 2 hours and 54 STC (see Chapter 4 for details). Imperial Plasters are available in 80lb. bags and in four formulas: Hand Tool Application and Machine Application finishes--for single-coat application composed of scratch coat and immediate doubling back, directly over large-size gypsum Imperial Plaster Base, glass-fiber tape and special comer bead. Provides a smooth trowel, float, or spray texture finish ready for further decoration. Hand Tool Application and Machine Application Basecoate-- for use in two-coat application with a lime putty finish. Can be applied to either Imperial Plaster Base, directly to concrete block, or over a bonding agent on monolithic concrete. Formu lated to receive high-strength gauged lime putty, Diamond Finish Plaster, STRUCTO-GAUCE-lime, or Keenes-lime-sand float finishes. The machine-application basecoat and finish are spray-applied only by the E-Z Coater Machine operated in strict accordance with the machine manufacturer's directions. - Mixing MIX IMPERIAL Plaster with a heavy duty drill capable of producing a minimum of 650 RPM under load. Place correct amount of water shown in table below in a 12 to 15-gal. smooth-sided container. Operate mixer, slowly add one bag (80 lbs.) plaster and mix for at least 3 min. to disperse lumps completely. Do not mix longer than 5 min. a co IMPERIAL Plaster Products Hand Tool Application Finish Water--Qts./80 lb. Bag. 11 to 13 o u Macnint Application Finish Hand Tool Application Basecoat Machine Application Basecoat 13 to 15 8 to 10 3 to 10 s o II 40 VENEER PRODUCTS: Imperial Plasters FOR SAND FLOAT FINISH add 20 lbs. clean silica sand per 80 lb. bag Imperial, Finish. FOR MACHINE APPLICATION add Imperial Catalyst solution at spray nozzle. For Imperial Finish, mix 3 lbs. (1 bag) Catalyst in 3 gals. clean water; lor Imperial Basecoat mix 9 lbs. (3 bags) Catalyst in 3 gals, clean water. Stir mixture until catalyst dissolves; let residue settle and pour into accelerator tank of machine. Application--IMPERIAL Plaster Finish APPLY Imperial Plaster Finish to a thickness of 1/16" min. to 3/32" max. over Imperial Plaster Base. First, embed tape and All beads with a tight, thin coat Imperial Plaster Finish and allow to set. When tapes and beads have set, scratch in a tight thin coat over entire area, immediately doubling back to full thickness. Fill all voids and imperfections. It is best to scratch and double back with same mix and avoid intermixing batches. FINAL TROWEL after surface has become firm, holding trowel flat and using water sparingly. Do not over-trowel. Best results are obtained by planning the plastering to permit continuous application from angie to angle. FOR SAND FLOAT FINISH omit final troweling and instead, after surface has become firm, float to desired texture, using sponge, carpet or other float. Use water sparingly. FOR MACHINE APPLICATION adjust material and catalyst flow control to give 60 to 90-min. set. Check on scrap piece of base by timing set. Spray all taped joints and over flanges of comer bead. Immediately trowel to completely embed tapes and bead flanges and leave surface level, without voids. Spray Imperial Plaster Finish to 1/16" thickness in two coats. Apply first coat approx. 1/32' thick, then cross spray to uniform 1/16" thickness. Do not apply more than 3/32" thickness. Trowel to fill voids, depressions and level surface. Final trowel as described above. FOR MACHINE TEXTURE FINISH apply plaster as above, but omit final troweling. Level surface to remove trowel marks, voids, catfaces and other defects. Apply texture coat as soon as base application has set. Set the catalyst flow control to produce IS to 20-min. set. Do not allow base application to dry before texture finish is applied. Application--IMPERIAL Plaster Basecoat ' TO IMPERIAL PLASTER BASE: apply Imperial Piaster Basecoat to a thickness of 1/16* mm. to 3/32" max. as described above for Imperial Plaster Finish. Omit final trowel and instead leave surface rough or cross rake with BB013 0206 Imperial Plasters: VENEER PRODUCTS 41 fine wire rake. Allow baseeoat to set and dry sufficiently to provide proper suction for following finish coat. TO MONOLITHIC CONCRETE: apply IMPERIAL Plaster Basecoat only to interior, structurally sound, clean, reasonably smooth surfaces prepared for plaster with a bonding agent applied according to directions. Fill all voids and depressions with Imperial Baseeoat; allow to set and partially dry. Scratch in a tight, thin coat over the entire area, immediately doubling back to 1/16' to 3/32' thickness. Leave rough and allow baseeoat to set and dry prior to finish application. TO CEMENT BLOCK: apply Imperial Plaster Baseeoat only to interior cement block surfaces that develop proper suction or are scored to provide adequate mechanical bond. Surfaces should be sound, clean and reasonably smooth with broken or chipped units replaced or repaired. Prior to plastering, lightly spray walls with water to provide uniform suction. Fill and level all voids, depressions and joints with Imperial Plaster Baseeoat. After sufficient take-up has occurred, apply scratch coat to entire area, and immediately double-back to 1/16' to 3/32' thickness. Leave rough and allow baseeoat to set and dry prior to finish application. FOR MACHINE APPLICATION adjust material and catalyst flow control to give 25 to 35-min. set. Check on scrap piece of bass ^ timing set. TO IMPERIAL PLASTER BASE: spray Imperial Plaster Baseeoat over all taped joints and corner bead flanges; trowel level. Apply Imperial Baseeoat to 1/16' thickness in two coats: first coat approx. 1/32' thick; then cross spray to uniform 1/16' thickness. Allow baseeoat to set and dry prior to finish application. TO MONOLITHIC CONCRETE: apply Imperial Baseeoat only to interior, structurally sound, clean, reasonably smooth surfaces properly prepared with a high-quality bonding agent. Spray a leveling coat, filling ail voids and depressions. Allow this coat to stiffen and level with light troweling. When set, spray second coat Imperial Baseeoat over entire surface with a coarse, sharp texture pattern. Total thickness for both level ing and texture coat need not exceed 3/32'. Allow baseeoat to set and dry prior to finish application. a TO CEMENT BLOCK: apply Imperial Baseeoat only to interior cement block surfaces that develop proper suction or are 2 (0 scored to provide adequate mechanical bond. Surfaces should (j be sound, clean and reasonably smooth with broken or O ' chipped units replaced or repaired. Spray a leveling coat to a- fill voids and depressions; trowel lightly to level. When set, SE spray second application baseeoat to a total thickness not to exceed 3/32' for both coats. Allow to set and dry prior to finish application. 42 VENEER PRODUCTS: Diamond Finish ' ' ^1 DIAMOND Finish Plaster A mill-prepared finish plaster to be applied over previously prepared conventional sanded or Imperial basecoats. It is de signed to meet today's plastering requirements for faster, easier application, greater strength and smoother appearance. Pre-mixed at the factory, it requires addition of water only on the job. Thus, mixing time is cut, gauging and soaking eliminated. Also provides stabilized set and constant highquality job performance. Its excellent troweling and easier working properties offer time-saving features that increase production without raising labor costs. Diamond Finish Plaster offers superior surface hardness-- 1V4 times as great as a I to 3 mix of regular gauging and lime. Its excellent resistance to abrasion, cracking and de lamination from basecoat makes Diamond Finish Plaster ideal for use on all interior surfaces where durability and hard wear are expected. Available in two formulations: Regular Set for use over conventional sanded gypsum basecoat, and Quick Set, for use over thin veneer basecoat such, as Imperial Plaster. Not recommended for use over lightweight aggregate gypsum basecoat. Mixing and Application MIXING: equipment used for mixing must be ciean. For mix ing Diamond Finish Plaster use a high-speed, motor-driven, propellor-type mixer. Place clean water in mixing container, slowly add one bag of plaster and mix for at least 3 min. to disperse lumps completely. Do not mix longer than 5 mm. 0 APPLY over a partially dry sanded gypsum basecoat or 0 O Imperial Basecoat. Scratch in the thin coat, well ground into r- the base, and immediately double back with second coat, fill (J. ing imperfections. Water-trowel to a smooth finish, free of all blemishes. Continue troweling until final set has taken place. Clean tools and equipment after each mix. Radiant Heat Plaster: VENEER PRODUCTS 43 RED TOP Radiant Heat Plaster This is a specially fortified high-strength veneer type gypsum plaster used in electric cable ceilings. Developed after years of research and testing, this unique product provides more efficient heat transmission and greater resistance to heat de terioration due to a chemical fortification in the plaster. Cable operating temperatures can reach as high as 135*F. provided heating cable wattage of 2.75 watts per lin. ft. and watt density of 25 watts per sq. ft. (a minimum cable spacing of 1H' o.c. as specified by National Electric Code, 422-52b) are not exceeded. This is in lieu of the Gypsum Assn, maxi mum temperature restriction of 125' F. for heating elements in contact with conventional plaster. Factory-mixed Red Top Radiant Heat Plaster requires addi tion of water only on the job. Hand-applied in two coats--a 3/16* fill coat to embed cable, then a finish coat of 1/16", which gives a total thickness of V4". Applied only to largesize Red Top Radiant Heat Plaster Base or directly to properly prepared monolithic concrete ceilings. This is the only plaster system recommended by United States Gypsum for use with electric cable heating systems. Mixing and Application MIX Red Top Radiant Heat Plaster with a heavy duty drill capable of producing a mimmum of 650 RPM. Do not hand mix. Slower operating drills will adversely affect setting properties of plaster. Since this material will set in approximately 1 hr., mixing and application must be coordinated so that no more material than can be applied in 30 min. is mixed. Do not retemper. Place approximately 15 to 17 qts. of water in a 12 to 15-gal. smooth-sided metal container, about 14* in diameter, and, with mixer operating, slowly add one bag of piaster. Mix for minimum of 3 min. to disperse all lumps completely, but do not mix longer than 5 min. Mixing equipment and tools must be kept clean to prevent acceleration from set plaster or other contaminants. 44 VENEER PRODUCTS: Radiant Heat Plaster Application over RED TOP Radiant Heat Plaster Base Apply Red Top Radiant Heat Plaster to a 14" total thickess over Red Top Radiant Heat Plaster Base. Apply a fill coat of the plaster parallel to the cable direction and of sufficient thickness to completely cover the cable. Do not use cables as a screed. Level this fill coat with trowel, rod or darby to fill any low spots or remove any high ridges, etc. "Tooth" the fill coat to provide key for finish coat, by using a serrated darby or by lightly brooming prior to set. The average fill coat thickness should be 3/16". After fill coat has developed sufficient suction (in good drying weather, about 2 hrs. after fill coat has set; in damp and/or cold weather the time interval might possibly extend overnight, unless good supplementary heat and ventilation are pro vided), apply a finishing coat of Red Top Radiant Heat Plas ter to provide Vi" total thickness. Fill all voids and imperfec tions. Final trowel when surface has become firm. Avoid using edge of trowel during final trowelling. Use water sparingly. Do not over-trowel. Always work to a wet edge. Avoid dry joining. FOR SAND FLOAT FINISH: application of fill coats should not be altered. A Sand Float Finish may be obtained by adding up to 20 lbs. clean white silica sand per 80-lb. bag Red Top Radiant Heat Plaster, depending upon texture desired. The quantity of sand added per bag must be consistent. Applica tion of Sand Float Finish is the same as outlined for trowel finish, except that when it has become firm, but unset, float to the desired texture, using a sponge, carpet, or other float. Use water sparingly. FOR SIMULATED ACOUSTICAL FINISH: a maximum Vi' thick ness of Impouax. QT Texture Finish, QT Simulated Texture Finish or similar product may be spray applied over the full Vi' thickness of Red Top Radiant Heat Plaster. Application over Monolithic Concrete Ceilings Red Top Radiant Heat Plaster must only be applied to interior, structurally sound, clean, reasonably smooth sur faces prepared for plaster with a bonding agent. Install radiant heat cable in accordance with specifications. After the radiant heat cable has been installed, apply Red Top Radiant Heat Plaster to an approximate 5/16' thickness to completely cover cable and anchor devices, followed by a 1/16' finishing coat that may be sand float finished if desired. BBOt3 o a io ! Base Application: VENEER PRODUCTS 45 Single layer wall application Resilient ceiling application APPLICATION OF VENEER BASES Veneer Gypsum Base Imperial Plaster Base provides an economical, durable, fireresistant, easily applied base for high-strength veneer plas ters in interior wall, ceiling and partition construction. This base may be applied in one or two layers directly to wood framing members, to metal studs or channels or to gypsum coreboards. SINGLE LAYER APPLICATION is used on interior walls and ceilings not exposed to extreme or continuous moisture where economy, fast erection and Are resistance are required. It is equally suitable for remodeling, altering and resurfacing cracked and defaced areas. DOUBLE LAYER APPLICATION: a face layer of Imperial Plas ter Base is job-laminated to a base layer of Imperial Base directly attached to framing members. This construction offers greater strength and higher resistance to fire and sound transmission. Walls and ceiling so constructed are highly resistant to cracking and minimize the possibility of fastener "pops" and discoloration over fastener heads. - FASTENING METHODS: veneer bases are applied by several alternate methods depending on the type of supports and ma terials used: 1. single nailing: conventional attachment for wood fram ing. 2. screw attachment: USG Screws are the best known in surance against fastener pops caused by loosely attached base. Recommended in wood frame application; required with sys tems employing metal studs, metal channels and resilient channels. 3. adhesive attachment: the latest advancement for produc ing high sound control and the finest room interiors. Usually requires only supplemental fasteners to attach face layers to base layer or gypsum coreboard. BB013 0311 I 46 VENEER PRODUCTS: Framing FRAME SPACING AND ATTACHMENT Framing Mas. Frame Spacing C. to C. Attachment Fastener Spacing C. to C. K' IMPERIAL Plaster Base wood Nails--LH* 13 ga.. "/ii" head, 16'to 24* ring or barbed shank, blued, polished, or cement coated 7' clgs.. 8' walls USG metal stud RC-1 resilient channel 16- 16' dgs. 24* wails Screws--USG l1/.' Type W Nails for Type X Lath--1H * 5d cooler type--cement coated Screws--USG l' Type S Screws--USG l" Type S 12' 6' dgs.. 7' walls 12' 12' H" IMPERIAL Plaster Base wood Nails--1*4'13 ga.. "A' head, 7' dgs.. ring or barbed shank, blued, 8' walls 24' polished, or cement coated USG metal stud RC-1 resilient channel Screws--USG IK' Type W 16' single layer Nails for Type X Lath--LA' 6d cooler type--cement coated 24' double layer Screws--USG I' Type S 16'dgs., Screws--USG l1/.' Type W 24' walls for channel to framing; USG 1' Type S for piaster base 12' 6' dgs., 7' walls 12* 12' K" RED TOP Radiant Heat Plaster Base wood lasts 16' Nails--ll/' 13 ga.. "AT head, T clgs. ring or barbed shank, blued, polished, or cement coated Screws--USG IK' Type W 12' Nails for Type X Lath--1V4' 5d cooler type--cement coated 6' dgs. RC-1 resilient channel 16' Screws--USG IK'Type W 12' for channel to framing; USG 1' Type S for plaster base USG metal channel 16' Screws--USG 1'TypeS 12' M" RED TOP Radiant Heat Plaster Base wood lasts 24' RC-1 resilient channel 24' USG metal channel 24' Nails--1H' 13 ga.. "A*' head, nng or barbed shank, blued, polished, or cement coated Screws--USG IK' Type W Screws--USG IK' Type W for channel to framing; USG 1' Type S lor plaster base Screws--USG 1' Type S 7' dgs. 12' 12' 12' C IO 0 1 JL A Framing: VENEER PRODUCTS 47 WOOO FRAMING meeting the following minimum require ments is necessary for proper performance. Framework shall meet the minimum requirements of FHA and local building codes. Framing members shall be straight, true, of uniform dimension, and framing shall be properly aligned. All fram ing lumber shall be of the proper grade for the intended use, and 2"x4" nominal size or larger shall bear the grade mark of a recognized inspection agency using grading rules for lumber recommended by the American Lumber Standards Committee. All framing lumber shall have a moisture content not in excess of 15% at the time of gypsum base application. Use of kiln dried lumber for joists is recommended. Do not attach base to extremely hard (dense) or soft framing members. NAIL POP: a protrusion, from an otherwise smooth surface, located directly over the head of a nail. The protrusion or bump is caused by an outward movement of the concealed nail head in relation to the finished surface, or it can be caused by an inward movement of the finished surface in relation to the nail head. Nail popping may occur whenever materials of any kind are joined with nails of any kind, size or shape. Nail pops are caused by nail heads puncturing face paper, lack of pressure on base during nailing, base improperly fitted, nailing base from ends and edges toward center, framing members out of alignment bowed or twisted, base applied over protrusions, nails insecurely driven, nails loosened by pounding, use of improper nails, or lumber shrinkage. Failure to observe these minimum framing requirements will materially increase the possibility of ineffective fastener con cealment, due to poor application practices, shrinkage of lumber, or a combination of the two. Check the studs, plates, joists, headers, heating ducts, electrical attachments and plumbing pipes to see that none will cause the base to be held away from the fastening surfaces of the framing members. Straighten any bowed, twisted studs or joists. Shim as re quired. HORIZONTAL VS. VERTICAL APPLICATION: IMPERIAL Plaster Base may be applied horizontally (long edges of the base at right angles to the framing) or vertically (long edges parallel to framing). Fire rated'partitions generally require vertical application. In wood frame construction horizontal application is gener ally better because it offers the following advantages: 1. Strongest dimension of base runs across framing members. 2. Bridges irregularities in alignment and spacing of framing. 3. Better bracing continuity--each panel ties more framing members together. BB013 0213 rI 48 VENEER PRODUCTS: Installation/lMPERiAL Base Horizontal application Vertical application 4. Reduces lineal footage of joints up to 25%. 5. Joints on walls are at a convenient height for finishing. For wall application, if ceiling height is 8'2" or less, horizon tal layout of base will result in fewer joints, easier handling, and less cutting. If ceiling height is greater than 8'2' or wall is 4' wide or less, vertical application will be more practical. For ceiling application, use whichever method will result in fewer joints. Installation of Plaster Base WOOD AND METAL FRAMING: IMFSUAI. may be applied in either a vertical or horizontal direction. All ends and edges of base should occur over framing members, except when edge joints are at right angles to framing members as in horizontal application. The plaster base should be applied first to ceilings and then to walls. To minimize end joints, use maximum practical lengths. Bring base into contact, but do not force into place. Where ends or edges abdt, fit them neatly. Stagger end joints. Arrange joints on opposite sides of partitions so as to occur on different studs. Fastening should proceed from central portion of base toward ends and edges. While fasteners are being driven, hold base in firm contact with underlying support. Space fasteners as shown in Frame Spacing and Attachment chart, I page 46, and not less than H' from edges and ends of base. I Set fastener heads flush with surface of paper out not break- B ' I ing paper. Where base appears too use double fastening. loose from stud or joist, Cd O ** Intenor vertical and horizontal angles should be floated by U not fastening to framing members in angles. When framing members are at right angles to interior angle, fasten approx. 8' away from angle. :r Installation/IMPERIAL Base: VENEER PRODUCTS 49 Cut and fit base neatly for pipes, electrical outlets, medicine cabinets, etc. Cut boles for electrical outlet boxes with special outlet box cutting tool. For circular holes, use adjustable cir cular cutting tool Remove any loose face paper at cut and use quick setting plaster to fill any holes or openings. GYPSUM BASES: Imperial Plaster Base face layers are joblaminated to 1' Gypsum Coreboard in solid and double solid systems and may be laminated in double layer construction in steel studs. Latter may have face layer screw-applied. At tachment is with USG Laminating Adhesive and USG 1V4" Type G Screws. Face layers are attached by applying ad hesive in vertical strips to base layer, strip lamination. Mix Adhesive in a clean metal container using approx. 11 gal. of clean cool water per 25-lb. bag. Sift powder into water, stimng continuously and mix until smooth. Adhesive will thicken and is usable after 30-min. soaking period. When necessary, consistency of mix can be adjusted by adding small amounts of powder or water. Wet mix may be held for up to 24 hr. by covering with small amount of water. Strip Lamination is suitable for vertical application of face layer panels on walls, significantly reduces the amount of adhesive used, and simplifies attachment of the face layer. Strip lamination provides Hush even edge joints and is rec ommended when a high degree of sound control is required. It is not intended for use on ceilings or for horizontal applica tion of face layers. Precut and prefit face panels as required and apply adhesive in vertical strips 24* o.c. to base layer or coreboard. Each strip should consist of four beads approx. %" wide at base and V4' high spaced 1H* to 2* o.c. Adhesive is applied most easily with a 7* or 10* Ames laminating head. Permanently attach face board to base layer or core units with " USG Type G Screws located so they penetrate adhesive strips (see diagram for installation of Type G Screws). - 1 r! w / 50 VENEER PROOUCTS: Joint Reinforcing \ X >> Staple application of IMPERIAL Tape Application of Joint Reinforcing APPLY Imperial Tape over all Imperial and Red Top Radiant Heat Plaster Base joints (edges and ends) with a springdriven hand stapler using staples. Tape should be applied over the full length of all joints 6ut must not overtap at intersections. Affix tape with two staples at top of tape--one on each side of the joint, 24" o.c. along length of tape, alter nating from side to side, with two staples at bottom. At wall-ceiling intersections, staple tape every 18' to 24" along ceiling edge only; for wall and partition interior cor ners, staple every 18' to 24" on one edge only, working from top to bottom. Position tape to bridge the joint at all interior comers. For fire-rated assemblies, staple tape 8* o.c. alternate METHOD: Under certain adverse climatic or job conditions, veneer piasters can develop a small ridge or bead over the piaster base joints. Such joint deformation is more likely to occur when low humidity or rapid drying job con ditions exist during lathing and plastering stages, such as in dry arid climates, or during cold winter weather when dry temporary or permanent heat is used. This condition is not the result of a product defect. Standard joint reinforcement procedures will minimize or effectively eliminate the hazards of joint deformation. In those instances where extremely dry job conditions are known to exist and the standard recom mendations prove insufficient, the following alternate joint reinforcement procedure should be substituted. ' < 1. Mix Dukabond Joint Compound according to directions on bag. Using a 5" broad steel finishing knife or trowel, butter compound over joint areas formed by edges and ends of Imperial Plaster Base; take care to avoid heavy fills. Cement PatF-A-TAPE Reinforcement and press it down with fresh joint compound. Hold knife or trowel at an approx. 45* angle to board. Draw knife or trowel along joint with sufficient pressure to remove excess compound. Leave sufficient com- S q>*CA g. T I ! I Metal Accessories: VENEER PRODUCTS 51 pound under tape for proper bond, but not over 1/64' under feathered edge. When tape is embedded, apply a skim coat of joint compound over tape. After embedding and skim coat are completed, apply a finish coat feathered 3' to 4' beyond edges of first coat. This same procedure should be used for interior angles. 2. Use Durabond Joint Compound to fill trim and corner beads. Apply liberally, filling to nose of beads and feathering material 6' to 8' from nose. Smooth compound to remove excess material from nose of bead, leaving approx. 1/32' ground for finish plaster. 3. Allow applications over both joints and beads to set and dry thoroughly, before application of finish plasters. Application of Metal Accessories CORNER BEAD should be applied to all external angles, held tightly over base and nailed or stapled not over 12' o.c. on both flanges along entire length of bead. When bead is in place, inside nose should be flush with base comer. Use 800-A for plaster thickness up to H"; 800-B for 1/16' grounds. METAL TRIM: fasten Imperial Plaster Base in normal man ner but omit fasteners at framing member where metal trim is to be installed. Leave a space H'xV4' wide between edge of base and face of jamb or wall. This spacing adds a fluted T ! i effect to openings and provides space for hardware or door bucks. It also allows expansion when trim is used for perim eter isolation. Slip 700-A trim over edge of base, or position 700-8 trim over comer of base with perforated flange on room side. Fasten to base by nailing or stapling not over 12' o.c. CONTROL JOINT: apply USG Control Joints No. 093 over face of Imperial Plaster Base where specified. Cut to required q lengths with a fine-toothed hack saw (32 teeth per in.). Cut end joints square, butt together and align to provide near fit. U Attach control joint to plaster base with 9/16' staples spaced q not over 6' o.c. in each flange. The protective plaster tape (Q applied over the open groove should be left in place until fasten- ** ing is completed. 'd 52 VENEER PRODUCTS: Runner Installation Application of Structural Accessories Runner Installation Imperial Plaster Partitions are secured to floors, ceilings and abutting walls with runners fastened to the supporting structure. The USG Metal Runner, a metal channel, is used with various systems employing USG Metal Studs. The USG Solid and Double Solid Imperial Partitions are attached with a metal angle runner. A wood runner may be used when a nailer for wood base trim is needed, but generally is not acceptable when a Are rating is required. To improve the sound control characteristics of a partition, a non-hardening caulking material. Plastic Sealer No. 579.64 as manufactured by Presstite Division of Interchemicai Co. or equal, should be used under all wood and metal runners to seal the runner to the structure. Caulking of metal runners and plasterbase of Imperial Systems is required to obtain sound ratings shown in Chapter 4. CAULKING: surfaces to be caulked should be clean, dry and free of all foreign matter. Using an air pressure-activated or hand caulking gun, apply non-hardening caulking compound in beads about 44 ' diam. on either side of runners and studs at juncture with floor, ceiling and walls. Use single beads under angle runners. Then caulk perimeter of plasterbase after it is installed. Caulking material will keep its proper tacky consistency if stored on the job in an insulated box heated with a 100-watt light bulb. Caulking of runner tracks B B O li r Runner Studs: VENEER PRODUCTS 53 Fastening channel runners Fastening angle runners FASTENING: after caulking, securely attach runners, 1. To concrete slabs using concrete stub nails, shielded screws, or power-driven fasteners. 2. To gypsum or concrete block walls using square cut nails or power-driven fasteners. 3. To suspended ceilings using expandable molly type fasten er or toggle bolts. 4. To wood framing using 12d nails or suitable screws. Secure runners with fasteners placed at corners, at runner ends and spaced not to exceed 24' o-c. on floor runner and 16' o.c. on ceiling runner, exception: fasteners securing ceiling runners on solid and double solid partitions may be spaced 24* o.c. At partition corners, extend one runner to end of corner and butt other runner to it allowing clearance for plaster base thickness as necessary. Runners should not be mitered. STUD ERECTION: Insert floor-to-ceiling height USG Metal Studs between runners, twisting them into position. Anchor all studs adjacent to door and borrowed light frames, parti tion intersections and corners to floor and ceiling runners. Use the USG Metal Lock Fastener or positive screw attach ment with H' USG Type S Screws, pan head, through each stud flange and runner flange. 54 VENEER PRODUCTS: Screw Application Erection of USG Coreboard COREBOARD ERECTION: cut 1" coreboard to fit between floor and ceiling metal angle runners. Before installation, cut nec essary openings in coreboard to accept electrical services (i.e. rigid conduit, flexible cable, electrical boxes, etc.). Install coreboard vertically, exposing rounded tongue edge. Secure each coreboard to metal angle runners both floor and ceiling with two H4" Type S screws placed about 2' from vertical edges. Application of Fasteners Screw Application USG Screws are applied with a positive-clutch electric screw driver, equipped with adjustable screw depth control head and a Phillips bit. The use of screws provides a positive mechanical attachment of plaster base to wood and metal framing with fewer fasteners than when nails are used. Cor rect use of electric screwdriver is shown below. SET SCREWORIVER: set adjustment for proper screw depth on scrap plaster base and framing. Drive screw head slightly r1 Screws and Nails: VENEER PRODUCTS 55 below face of base but not deep enough to break the paper. To adjust, grasp control head firmly with one hand and loosen control head lock bushing with the other. Rotate con trol head to provide proper screw depth. When proper adjust ment has been made, positively secure control head to main tain adjustment. PLACE SCREWS: magnetic tip holds screw for driving. Bit tip does not rotate until pressure is applied to plaster base dur ing application. ENTER SCREW STRAIGHT: firm hand grip on electric screw driver is important for straight line of entry. Screw must enter perpendicular to panel face for proper performance. Drive screws at least H" from ends or edges of base to provide a uniform dimple not over 1/32" deep. The electric screwdriver handling technique is relatively simpie to learn and a proficiency with the tool can be developed after a few hours' use. The following procedures are recom mended: 1. Allow motor to run continuously during usage. 2. Seat screws into boards with one thrust. Re-application of thrust pressure may cause clutch to re-engage and chew up screw head or force the screw head below the surface of the plaster base. 3. See illustrations, previous page, showing proper setting and adjusting of screwdriver depth locator. Nail Application Begin nailing from central portion of base and proceed toward outer ends or edges. When nailing, apply pressure adjacent to nail being driven to insure base is secured tightly on framing member. Position nails on adjacent ends or edges opposite each other and at least H" from ends and edges. Drive the nails with shank perpendicular to plaster base. The nail heads should be driven flush with paper surface but should not break paper. A nail set should not be used. Where base appears too loose, a second nail should be driven within 2" of first nail while applying pressure to bring base in firm contact with framing. j ! , . ' ' j j ! \ ' . j j I, j! r ................................................ - ------------- CHAPTER 3 S Standard Productss and Application| j .** * * * * #* * chapter 3 page Plaster Basa Products 59 Rocklath Gypsum Bases 60 Metal Lath 63 Gypsum Partition Tile 66 Trim Accessory Products 67 Corner Bead 63 Casing Bead 69 Metal Trim 70 Control Joints 70 Structural Accessory Products 71 Floor and Ceiling Runners 72 Metal Base and Clips 73 TruSSTEEL Studs and Track 74 ' USG Metal Studs and Runners 75 Channels--Cold Rolled. Resilient. Furring 75 Fasteners and Attachment 76 Gypsum Plasters, Lime and Application 32 Basecoat Plasters 82 Finish Plasters 87 Gauging Plasters 93 Finish Limes 96 Acoustical Plasters 100 Special Plasters 102 Sound Control Products 103 Paint Products 104 CHAPTER 3 Standard Products and Application QUALITY PLASTERING PRODUCTS It is universally acknowledged that a completed plaster job can be no better than the basecoat or finish materials used, and the base to which they are applied. In the years since the company's formation in 1902, United States Gypsum plaster ing products have earned the overwhelming preference of the marketplace. They have earned it on one basis: performance. This record of performance extends through the complete USG line--broadest in the industry--of plaster and lime products, plaster bases and accessories. It rests largely on the compatability of components in the plastered wall or ceil ing assembly--ail designed by U.S.G. to work together. Com ing from a single source, they are most capable of satisfying the specific requirements of the job. Presented on the following pages are the basic materials recommended by United States Gypsum Company for quality plaster wails and ceilings. They are designed to meet the essential requirements of economy, speed of installation, fire and sound resistance, strength and ease of decoration; pro duced to rigid specifications and carefully quality-controlled throughout their manufacture. These manufacturing safe guards are backed by regular testing and constant product improvement at the USG Research Center, largest and best equipped in the industry. The USG trademark on a product is your assurance of consistent high quality and proven per formance to meet your construction needs. United States Gypsum maintains special plaster sales repre sentatives to consult with contractors, architects and dealers on plastering materials, systems, and special job conditions. They may be reached through the nearest USG Sales Office (listed inside back cover) or by writing to United States Gypsum, Dept. 147, 101 S. Wscker Dr., Chicago, 111., 60606. Wo PLASTER BASES U Proper use of USG piaster bases and plasters provides the q secure bond necessary in order to develop strength and re- M sistance to abuse and cracking. A "mechanical" bond is A) formed when plaster is pressed through the mesh or holes of the lath, forming keys on the back side--as with metal lath 60 PRODUCTS: ROCKLATH Bases or perforated gypsum lath. A "suction" bond is formed when gypsum plaster is applied over gypsum lath and masonry bases; the tiny needle-like plaster crystals penetrate into the surface pores of the base by suction. When perforated gypsum lath is used, both suction and mechanical bonds are developed. ROCKLATH multi-ply face paper Gypsum Plaster Bases Rocklath, Imperial and Red Top Radiant Heat Plaster Bases are gypsum lath in sheet form providing a rigid, fire-resist ant base for the economical application of gypsum plasters. Rocklath requires about 45 percent less basecoat plaster than with metal lath. The gypsum core of this lath is faced with multi-layer lami nated paper formulated by an exclusive U.S.G. process to check plaster slide and resist lath sag. As illustrated, the three outer layers (1) are made super-absorbent to draw moisture from the plaster mix so uniformly and so quickly that the plaster takes on anti-slump strength before it can slide; the inner layers (2) are chemically treated to form a positive barrier against moisture penetration, thus prevent softening of the gypsum core and consequent sag after board is in place. The face paper is folded around the long edges of all three types of gypsum bases; in addition, the ends of Imperial and Red Top Radiant Heat bases are square-cut and linished smooth. See Chapter 2 for details. These gypsum bases are fabricated in three thicknesses and - in eight different products for specific uses as listed below. ' Rocklath complies with ASTM C37, and Fed. Spec. SS-L- 0 30b. Other features found in gypsum piaster bases are: $ O INCOMBUSTIBLE: when used with gypsum plaster, gypsum piaster bases provide for excellent fire-resistant construction; W up to 2 hrs. for partitions and 4 hrs. for ceilings and column q finproofing. err STRENGTH: when securely attached, gypsum plaster bases add lateral stability to the assembly. ' t Rocklath Bases: PRODUCTS 61 SOUND RESISTANCE: partitions faced with gypsum plaster bases and plaster on both sides have high resistance to sound transmission; resilient attachment further improves ratings; makes assemblies suitable for party walls. BONDING: gypsum piaster bonds to these gypsum plaster bases with a safety factor far higher than required to meet usual construction standards. DURABILITY: not harmfully affected by decay, dry rot, or normal moisture; will not attract vermin. ECONOMY: low cost, ease and speed of erection and savings in plastering are outstanding. Rocklath, Imperial, and Red Top Radiant Heat Plaster Bases are made only by United States Gypsum. GENERAL LIMITATIONS 1. Max. framing spacing: %" thick Rocklath, 16" o.c.; Vt" Rocklath, 24" o.c.; H" veneer bases, 16" o.c.; H" veneer bases, 24' o.c. Some deviation from the above is permitted in certain constructions (see system descriptions, Chapter 4). 2. Should be used with gypsum plaster only. Bond between lime or Portland cement plaster and Rocklath is inadequate. 3. Gypsum lath and plaster, painted, has a vapor permea bility of about 34t perms. For higher resistance to vapor transmission. Insulating Rocklath Plaster Base (see page 62) should be used. 4. Should not be used in areas exposed to excessive moisture for extended periods. USG galvanised metal lath and port land cement-lime plaster are recommended. PLAIN ROCKLATH PLASTER BASE is recommended for nail or staple application to wood and nailable steel framing, for clip attachment to wood framing, steel studs and suspended metal grillage, and for screw attachment to USG Metal Studs and Furring Channels. PERFORATED ROCKLATH PLASTER BASE is identical with Plain Rocklath except that \' round holes are punched 9b- cs* 62 PROOUCTS: rocklath Bases Screw application of ROCKLATH Plaster Base Clip attachment of ROCKLATH Plaster Base through the lath 4" o.c. in each direction, one ri" diam. hole for each 16 sq. in. of lath area. This provides a mechanical key in addition to the natural plaster bond, and obtains higher fire ratings. Not recommended for attachment to ceil ings, either wood framing or metal grillage, where the only support provided is by clips at edges. ROCKLATH FIRECODE PLASTER BASE is a gypsum lath which combines all the advantages of Plain Rocklath with addi tional resistance to fire exposure--the result of a specially formulated core containing special mineral materials. LONG LENGTH ROCKLATH PLASTER BASE is manufactured for use in constructions requiring floor to ceiling height lath, such as the Solid Rocklath and Plaster Partition System and the USG Exterior Wall Purring System (see Chapter 4 for details). Lengths are mill cut as required up to 10 ft.; formed with longitudinal "V" edges. INSULATING ROCKLATH PLASTER BASE ofTers all the advan tages of Plain Rocklath as a rigid plaster base, is made in the same sizes, but has bright aluminum foil laminated to the back side. This creates an elective vapor barrier at no addi tional labor cost, to combat moisture condensation--a com mon cause of peeled exterior paint, warped siding and rotted studding. Its vapor permeability of 0.67 perms is well below the FHA permeability limit of 1.00. In addition. Insulating Rocklath provides positive insulation value when installed with the foil facing a min. air space. When used as a -, ceiling under winter heating conditions its resistance value is 2.69; in retarding downward heat flow in summer, its gf . effectiveness is nearly double for a resistance value of 4.88 BI ; including air space (see table page 63). Corrosion and normal dust accumulation exert negligible effect on the vapor bamer q ' and insulation characteristics of Insulating Rocklath. LONG LENGTH INSULATING ROCKLATH. also with aluminum foil laminated to the back side, is used primarily for furring exterior masonry walls. Lengths are mill cut as required up _ Metal Lath: PRODUCTS 63 to 12 ft.; formed with square edges. Thermal resistance val ues of Insulating Rocklath are as follows: THERMAL RESISTANCE VALUES Insulating ROCKLATH Surface, Hast Flow A Sasun honzontal horizontal vertical vertical (UP) (dm (hor) (hor) winter summer winter or summer H* 2.69 4.88 3.89 Vi* 2.82 5.01 4.02 MOTE. Rtiuiancvs ar mo or attll ir him. Yim undtd piastir, and indue* air sok* oi Vm or mot*. GYPSUM PLASTER BASES--TYPES ANO SIZES Product Thick ness. Length Width Approi. Wt. Pcs./ (lbs./ bdl. MSF) ROCKLATH plain, performed or insulating 54' Vi* 48*(2) 48* 16* (1) 6 16* (1) 4 1450 1980 ROCKLATH FIREC00E plain (1) K* 48* 16' 6 1500 Long Lengtn ROCKLATH plain or mutating H'(3) 4'to 12' 24' 3 1450 plain H*(4) 4' to 10' 24* 2 1980 IMPERIAL plain (5) V5* 8' to 12' 48* H* 8'to 12' 48* 2 1970 2 2460 IMPERIAL Type X (5) W* 8'to 12' 48' Yi' 8'to 12' 48' 2 2025 2 2460 RED TOP Radiant Heat plain (5) Vi* 8' to 12' 48* H* 8' to 12' 48* 2 1970 2 2460 Type X (5) Vi* 8' to 12' 48' 2 2025 *Umi(d distribution--ctitck (or local (variability. (1) Alio tvariabla m 16*1/5' widths hi **ate Coast araa--5 ocs./MI. (2) Plain and Porforatod typos also avaiiaMo in 96' lanftn* unbunoiod. (3) Furmshod with sfluara adfo. (4) Furntsnod with'V tdf*. ($) Sot Chaptaf 2 (or product doscriphon. (JSG Metal Lath USG Metal Lath is sheet steel that has been slit and ex panded to form a multitude of small mesh openings. It is made in Diamond Mesh. Riblath and Stuccomesh types and in two different weights for each style. All are manufactured from rust-resisting copper alloy steel, further protected by a coating of black ajphaltum paint, except diamond mesh, which is also available in galvanized steel. Ends of bundles of USG Metal Lath are spray painted in different colors for various weights, thus simplifying stock ing and handling. All 3.4 lb. lath is painted red; 2.5 lb. diamond mesh and 2.75 lb. Vi' nblath are white; 4.0 lb. H" riblath is yellow. As a plaster base, USG Metal Lath offers these additional features: STRENGTH: metal lath embedded within the plaster provides high resistance to transverse impact, thus decreases the BB013 0220 64 PRODUCTS: Metal Lath hazards of serious cracks and failures due to structural movement of the frame. FLEXIBILITY: readily shaped to ornamental contours to a degree not possible with other plaster bases. FIRE RESISTANCE: when used with gypsum plaster, metal lath provides excellent fire-resistant construction; up to 2 hrs. for partitions and 4 hrs. for ceilings and column fire proofing. USG Junior Oiamond Mesh Lath USG 4-Mesh Riblath USG ya' Riblath USG Vt' Riblath <ocUSG Expanded Metal Stucco Mesh USG B-V Lath USG JUNIOR DIAMOND MESH LATH is a small diamond mesh metal plaster base (approx. 11.000 meshes per sq. yd.). A general all-purpose lath, best for ornamental, contour piastaring. The small meshes conserve plaster and reduce drop pings. Also available in self-furring type having "dimple" indentations spaced ltt* o.c. each way for use as extenor stucco base, column fireproofing and for replastering over old surfaces. USG 4-MESH Z-RIBLATH is a "fiat rib" type of lath with smaller mesh openings, suitable for "double-up" type of plas tering. More rigid than diamond mesh, it is excellent as nail- . izco xioaa Metal Lath: PRODUCTS 65 on lath, and for tie-on work on flat ceiling?. Not recom mended for contour lathing. USG s" RIBLATH comes in a herringbone mesh pattern with %' V-shaped ribs running lengthwise of the sheet at 4H" intervals, with inverted intermediate 3/16' ribs. The heavy ribs provide exceptional rigidity. Used when supports are spaced more than 16' o.c. and not more than 24', and for 2' solid studless metal lath and plaster partitions. Also used as a centering lath for concrete floor and roof slabs. Unsuitable for contour plastering. Minimum ground thickness must be 1'. USG Vi" RIBLATH provides a herringbone mesh pattern with deep V-shaped ribs lengthwise of the lath at 6" intervals, it is a structural lath, providing the dual functions of center ing and reinforcement for concrete floor and roof slabs; for greater spans than permissible with It" riblath. It is not recommended as a plastering lath. USG EXPANDED METAL STUCCOMESH is a l%"x3tt" dia mond mesh pattern designed as a base for exterior stucco, hand or pump applied. It should be applied with lit" galva nized self-furring nails; when used over sheathing other than wood, longer nails providing min. penetration of lit' into studs should be used. USG B-V LATH has large It' diamond-shaped openings, which makes it suitable for reinforcement for many types of light concrete slab work. BB013 0230 Iss USG METAL LATH--TYPES, WEIGHTS, SUPPORT SPACING Maaimum Allowable Spacing Vertical Supports Horizontal Supports Wood Metal Type of Lath (1) Diamond Mesh Diamond Mesh (2) it' Z-Rib it* 2-Rib H' Rib H' Rib B-v Lath B-V Uth Stuccomesh (3) Stuccsmesh Weight Pr Sq.Yd. 2.5 lb. 3.4 lb. 2.75 lb. 3.4 lb. 3.4 lb. 4.0 lb. 2.51b. 3.4 lb. 1.8 lb. 3.6 lb. Size Sheets 27"x96' 27*x96* 27*x96* 27*x96* 27*x86* 27*x96* 24'x96* 24*z96* 48*z99* 48*x99* Solid Partitlons 16* 16* 16* 16* 16* 16* 19* 24' 24* 24* 16* (3) 16*13) 12* 16* 16* 19* 24* 24* Wood or Con crete (4) 16* 16* 19* 24* 24' Motal (4) 13 It* 12* 19' 24* 24* H* Riblath wt. per so. It. 0.60 lb. 0.75 lb. size shoots 2' x S', 10' or 12' NOTES: OiMMM MttA latftt ala*avotiiofa in styles. (1) All typo inMi trmm captor Mtoy stoot from 0.20% to 0.25% puff eotoor. IM pamtod with rustiMiBitrao Mac* aspfiaitum (Mint. (2) Alto avaMaMo in fiiaamsad staol. (2) Gantratly ippi*ad oaar (a5i)taIrMioor dwifitfffOfoiirftti*.*i(4f)urNnaotf. ffcammonoM aicopt for firaproofioc *f ***** ******* 66 PRODUCTS: PYROBAR Tile PYROBAR Partition Tile PyrobaR is a precast, kiln dried gypsum tile for building non load bearing fireproof partitions. It is made in I2"x30" sue, in four thicknesses with indented surfaces, in hollow and solid types as follows: 2' Solid 3' Hollow for column fireproofing 3* Solid, 3' Hollow, 4' Hollow and 6' Hollow for parti tions. Complies with ASTM C52, Fed. Spec. SS-T-316; offers the following advantages: FIRE RESISTANCE: PYROBAR provides the greatest fire protec tion per inch of thickness of any commercial partition assem bly; fire ratings up to 4 hours for partitions, vent shafts and column fireproofing. SOUND RESISTANCE: excellent sound transmission loss ratings when plastered two sides, further improved as suit able party wall construction by resilient lath and plaster facing on one side (see Chapter 4 for details). LIGHTWEIGHT: 30% to 50% lighter than other commonly used masonry units. ECONOMY: Fewer joints than with smaller masonry units: machine molded units lay accurately to form level surface, require less plaster and mortar than other types; easily cut, handled and maintained; ideal for tenant office renovations. PIASTER BONO: Pyrobak is the most compatible masonry plas ter base for gypsum basecoat piasters. LIMITATIONS 1. For use only in non-load bearing constructions. 2. Portland cement and lime mortars do not bond adequately Trim Accessories: PRODUCTS 67 with Pyrobar. Red Top Partition Tile Cement should be used. 3. Portland cement or lime plasters cannot be used over Pyrobar. Rm Top Gypsum Plaster should be used. 4. Pyrobar must be protected by a continuous coating of asphaltic material prior to any contact of wet flooring or base material with the face of the tile. PYROBAR GYPSUM TILE-TECHNICAL DATA Product 2* solid 3* solid 3' hollow 4* hallow 6' hollow Approx. Tile Wt. (psO 10 15 10 13 22 RED TOP Partition Tile Cement (bags/MSF) (1) 5 3 3 10 15 Sand (cu. ft./MSF) 15 24 24 30 45 (1) I00*<b. 6(s. RED TOP PARTITION TILE CEMENT is a specially prepared gypsum cement that develops high early strength; also is excellent for setting clay tile. Used as a mortar in mix of 1 bag per 3 cu-ft. of sand. Available in 100-lb. bags. TRIM ACCESSORIES TJSG trim accessories--corner reinforcements, screeds, metal trim, control joints, partition terminal and joint reinforce ment tape--enjoy the industry's top acceptance because of their dependability and continual improvement in design. USG Corner Beads should be used on all external plaster corners to provide plaster protection, true and straight lines at corners, and grounds for plastering; USG Casing Beads around wall openings and at intersections of plaster with other finishes. USG Screeds are used to divide different types of plaster finishes and as a separation between plaster and a cement base, or as a permanent incombustible screed to con trol plaster thickness and alignment beneath the wood or otherngid trim. They are made from top-quality galvanized steel--corner beads and screeds from 26-ga., casing beads from 24-ga. steel. 1-A EXPANDED CORNER BEAO has wide expanded flanges that are easily flexed. Preferred for irregular corners. Provides increased reinforcement close to nose of bead. BB013 0232 68 PRODUCTS: Trim Accessories 10-A Comer 4-A FLEXIBLE CORNER BEAD is a general purpose comer bead, economical and most generally used. By snipping flanges, this bead may be bent to any curved design (for archways, telephone niches, etc.). Can be secured to corners with 9-A Corner Bead Clips attached to flanges. 4- R EXPANDED CORNER BEAD is an outstanding item with small nose and totally expanded 2' wide flanges designed to increase plaster keys and minimize corner cracking. A gen eral purpose bead, suitable for straight or arched corners. 5- A BULL NOSE CORNER BEAD is radius bead with short flange. Used for rounded comers. Can be secured with 9-A Comer Bead Clips attached to flanges, where wide nailing flanges are required. 10-A EXPANDED BULL NOSE CORNER BEAD is a bull nose bead similar to above, but with 2H* wide expanded flanges. Especially suitable on irregular comers. CORNERITE AND STRIPLATH are strips of painted copper alloy Diamond Mesh lath used as reinforcement. Selv-edge Comerite, bent lengthwise in the center to form a 100' angle, should be used in all internal plaster angles where metal lath is not lapped or carried around; over non-ferrous iath an- -> chored to the lath, and over internal angles of masonry con- stractions. Its use is optional in Resilient Rocklath lathing Qt-l systems; also used in the "Floating Angle" method of apply ing gypsum lath to wood framing in order to reduce plaster cracking. Stripistil is a similar flat strip, used as a plaster (Jfc reinforcement over joints of non-metallic lathing bases and a where dissimilar bases join; also to span pipe chases. Qa Trim Accessories: PRODUCTS 69 USG CASING BEADS (styles shown below) are used as a plas ter stop and exposed to eliminate the need for wood trim around window and door openings; also recommended at junction or intersection of plaster and other wall or ceiling finishes. May be used with USG Metal Lath, Rocklath Gyp sum Plaster Base, or masonry construction. In order to insure proper grounds for plastering, casing beads are recom mended for use with metal lath, H' beads with all masonry units, T4" beads when the flange is applied under Rocklath Plaster Base, V4' beads when the flange is applied over Rocklath. USG CASING BEAD-PRODUCT OATA Style & Flange jU--Qtr. rd.--expanded #138--dir. rd.--short #60--sem-square-- expanded #60--semi-square--short #66--square--expanded #66--square--short Shipping Unit (Pcs.) 80 9 V or 8' 60S 10' Grounds & Shipping Wt./ MLF (lbs.) H' V 260 -- 230 -- 205 -- 227 232 222 -- 245 -- 167 -- 188 202 231 241 255 178 -- 202 212 3-A EXPANDED BASE SCREED is a flush type tt' ground (job shimmed for %' grounds) with wide flexible expanded flanges for added reinforcement; suitable for uneven surfaces. Used as a dividing strip between plaster and flush Portland i 1 .1 i; 1 70 PRODUCTS: Trim Accessories S-A T-IM4' [ * a, * * -'* 7-A M 17 Partition Terminal dW I 2" USG Control y* Joints *50. ___ L 75. ICO ^701^* 1* 6- A PLAIN BASE SCREED is a flush type V4" ground (job shimmed for grounds), used as a straight divider stnp between different types of plaster, as between gypsum and Portland cement. 7- A CURVED POINT BASE SCREED is a dividing strip for use between plaster surface and projecting Portland cement base. Upper ground is V4 ', bottom ground is 1". 8- A PICTURE MOULD provides a concealed mould, attached to lath and plastered flush to the notch opening, leaving a Vi" wide slot into which hooks may be inserted to support pic ture, maps, etc. Grounds V4' (job shimmed for Vi' grounds). USG 2' PARTITION TERMINALS are used as vertical terminals for 2' solid metal lath or RockLath Partitions. Can be used as a ceiling runner where 2' solid partitions abut an unplas tered surface. Formed of 24-ga. galvanized and bondenzed steel. USG CONTROL JOINT is designed to relieve stresses of both expansion and contraction in large plastered areas. Made from roll-formed zinc, it is resistant to corrosion in both interior and exterior uses with gypsum or Portland cement plaster. An open slot, Vi' wide and V4" deep, is protected with plastic tape which is removed after plastering is com pleted. The short flanges are perforated for keying and at tachment by wire-tying to metal lath or by stapling to gyp 0* to. sum lath. Thus the plaster is key-locked to the control joint, o i which not only provides plastering grounds but can also be used create decorative panel designs. Sizes and grounds: No. at i.50, 14"; No. 73, H"; No. 100, 1" (for uses such as exterior stucco, acoustical plaster work). 1 Structural Accessories: PROOUCTS 71 USG TRIM ACCESSORIES--'PRODUCT DATA Product i*A ftp. Corner Bead 4-A Flex. Corner Bead 4-R Exp. Corner 8ead 5-A Bull Nose Corner Bead (1) 10- A Exp. Bull Nose Corner Bead 800-A Corner Bead (3) 800-B Corner Bead (31 Cornente Shipping Unit (pcs.) 80 60 60 80 60 80 60 30 60 125 75 Ship. Unit Length (ft.) 7 or 8 9, 10. or 12 7,8,9 10. or 12 7,8 9. 10. or 12 7 or 8 9.10. or 12 7,8 9, 10. or 12 8 8 8 (2*x2'l (3*x3") Wt./MLf (lbs.) 195 179 155 245 350 136 75 90 133 Striplath 75 8 (4') (6'1 3-A Exp. Base Screed 50 10 6-A Plain Bast Screed 50 10 7-A Curved Point Base Screed 50 10 8-A Picture Mould 50 10 USG 2' Partition Terminal USG Metal Trim (3) 700-A 700-B USG Control Joint rSO 75 100 30 8 or 10 36 7,10 (V4') (V) 50 10 W) (*) 25 io tvn (Vi") (1*) USG Control Joint v093 (3) 30 8 25 10 IMPERIAL Tape (31 1 3.600 (2) r I) Fabricate on ordtr. < 2) Consists of 12 rolls 300 ft. to., par carton. <3) So* Chsocor 2 tor product dtscription. 95 133 196 164 172 231 498 98 106 74 80 172 192 216 112 - 9GC0 c io a a STRUCTURAL ACCESSORIES USG leads the industry in the development and acceptance of structural components for plastering systems. They offer the advantages of light weight, low material cost and quick erec tion, superior strength, and versatility in meeting job re quirements. AU are incombustible, made from cold rolled or galvanized steel or rods. USG runners, metal base and base clips provide secure an chorage, alignment and installation economies for various plaster partitions and wall furring assemblies. Both runners and base dips are pre-punched for quick attachment. Also included are two non-load bearing studs of the truss and channel types, complete with runner tracks, shoes and screws as needed; hat-shaped and U-shaped furring and lathing channels, and an adjustable wall fumng bracket. 72 PRODUCTS: Structural Accessories USG CEILING AND FLOOR RUNNERS, of 26-ga. galvanized steel, come in two models: L-Type Ceiling Runner providing ceiling anchorage for studless metal lath or Rocklath Solid Plaster Partitions, Z-Type Ceiling Runner to anchor and align %" channels in either solid partition construction or exterior wall furring. USG FLOOR RUNNER AND SCREED is a one-piece, channeltype combination unit used to anchor 2" solid lath and plaster partitions to concrete doors. Can be cut with a hacksaw or tin snips; fastens to floor with concrete stub nails or rawl drives. Base requires no grouting, except with studless metal lath partitions. One inch legs provide an excellent ground estab lishing the 2' thickness of the partition. Designed for covering with asphalt or rubber base, and may be installed over a 2' wide wood strip where nailing for wood base is required. Formed of 20-ga. cold rolled steel painted black. Also avail able with center guides positioned for use with s " and 1" Long Length Rocklath Plaster Base. USG METAL BASE makes possible flush installation of a 2Vt' high 18-ga. face plate adaptable to all plaster partitions and furred exterior walls, by means of specially formed steel clips. A strong, ragged base goes into place with minimum labor through snap-on application to the double base clip used in 2* solid plaster partitions or to the single base clip used with hollow partitions or furred walls. The ears of the floor dips engage the top flange of the face plates, automatically adjusting the face plates to uneven or irregular floors. The face plates are easily mitered or notched and bent to form outside comers. For inside comers or continuous uninterrupted runs from one type of wall construction to another, the face plates are butted. -- B# 5\ jy, SJ _1 Structural Accessories: PRODUCTS 73 As a floor runner with solid partitions, the base is grouted full with sanded plaster and raked out in a "V" to receive the Long: Length Rocklath. The base is mill-pruned with a rust inhibitive paint. USG METAL BASE SPLICE PLATES join the metal base face plates together quickly and in proper alignment. USG DOUBLE BASE CLIP is designed to secure a solid plaster partition to the floor and provide attachment of the USG 2H" Metal Base Face Plate to both sides. Available for the 2' and 214" Solid Partitions. USG SINGLE BASE CUP is used primarily as an attachment for the 2Vt" USG Metal Base Face Plate for furred walls or partition systems of varying widths. USG MASONRY BASE CLIP is designed for attachment of the USG Metal Base Face Plate to masonry; providing a 94' plaster ground. USG STUD BASE CLIP attaches the USG Metal Base Face Plate to studs. Clips may be wire tied, nailed or screwed to the studs. t 74 PRODUCTS: Structural Accessories TRUSSTEEL Stud Snap-In Runner Track TRUSSTEEL STUDS are the original open truss design studs for the erection of hollow, fire-resistant partitions. The strongest non-load bearing studs on the market, they are formed from cold drawn No. 7-ga. steel wire rods with a tensile strength of 90,000 psi--substantially higher than the hot rolled sheets from which pressed metal and edge angle studs are formed. Made with a continuous diagonal wire web welded to double wire flanges. Trussteix Studs are fabricated in five stud widths: 1H', ZVi", 314', 4' and 6", mill cut to job lengths. The open-web design readily accommodates pipes, conduits and ducts without impairing the strength of the partition assem bly. This engineered member, together with its accessories, provides a framework for easy direct or resilient attachment of metal lath or Rocklath plaster base. USG SNAP-IN RUNNER TRACK is used in anchoring the Trussteel Stud Partition to the floor. Attachment of stud to track is by a snap-in feature, eliminating the need for stud shoes. When the track serves as a ceiling runner, however, stud shoes are used if a lire rating is required. Available for all except the 6' width of Trusstsx Studs. USG REGULAR RUNNER TRACK is used in conjunction with Trussteel Stud Shoes to anchor the partition to the floor or ceiling, particularly where there is considerable floor-to-ceil ing height variation. Available for all widths of TRUSSTEEL Studs. Where top track is attached to suspended or furred framing, 1' tapping screws are used to anchor top course of lath into web wires of studs. TRUSSTEEL STUD SHOES: 7' long, are used for connecting 0* studs to regular track and permit up to a 4' adjustment in partition height. USG LATHING CHANNELS are cold rolled from 16-ga. steel, black asphaitum painted; used for furring, suspended ceil- Qings, partitions, and ornamental lathing. Sizes: ai", 1H", 2'. <2* 7f Structural Accessories: PRODUCTS 75 USG METAL STUOS are roll formed in three stud widths, 1%', 2 H' and 3%", from 25-ga. electro-galvanized steel. Their channel design allows economical 24' spacing of studs, and eliminates need for component accessories. Limited chaseways are provided by cutouts at top and bottom of the studs. They may be overlapped and spliced by means of screws or wire ties. USG METAL RUNNER is supplied in the three stud widths for use at floor and ceiling. The 25-ga. electro-galvanized steel tTack also functions as a header over metal door and bor rowed light frames. At the floor, the track may be used in combination with the USG 214" Metal Base and Stud Base Clip. USG FURRING CHANNEL is a roll formed hat-shaped section of 25-ga. electro-galvanized steel. It may be clip attached with USG Furring Clips to the 1H" main carrying channel for eco nomical screw attachment of Rocklatk as a base for either ad hesive attachment of acoustical tile or a basecoat plaster. The Metal Furring Channel also provides an incombustible furring for exterior walls with screw attachment of Rocklath or Imperial Plaster Base. USG ADJUSTABLE WALL FURRING BRACKETS are used for attaching 14' furring channels to exterior masonry walls. Made with serrated edges of 20-ga. galvanized steel, they are wire-tied to horizontal stiffeners in braced furring systems. Normal furring depth is 14' to 214'; with USG Furring Channels, depth is increased by %'. USG WALL TIES are T4'x7' corrugated galvanized steel an chors used to tie masonry veneer to the structure. USG TIE WIRE is 18 to 16-ga- galvanized soft annealed wire for tying metal lath to channels and furring to runner chan nels; also S-ga. Hanger Wire for suspended ceiling channel runners when spaced not more than 4 ft. o.c. rr--^ IIIlIEilSIlIKlIll : USG Wall Tie 76 PRODUCTS: Fasteners USG STRUCTURAL ACCCSSORIES-PROQUCT OATA Product Shipping Lengths Unit (ft) (pcs.) WL/M pcs. 1 lin. ft. USG Ceiling & Floor Runner L-Type ceiling runner 2-Type ceiling runner USG Floor Runner & Screed USG Metal Base USG Metal Base Splice Plate USG Double Base Clip USG Single Base Clip USG Masonry 8ase Clip 8 80 10 50 175 265 10 50 470 10 10 640 - 500 75 - 400 92 - 500 70 - 350 92 USG Stud Base Clip TRUSSTEEL Studs lK'-2K'-3'/.'-4'-6'widths - per order to |0b length 500 -- 53 400-515 USG Snap-In Runner Track 1H'-2K'-3K'-4'widths 8 10 .295-470 USG Regular Runner Track lH"-2K'-3K'-4'-6' widths 8 10 200-525 TRUSSTEEL Stud Shoes - 500 30 USG Metal Studswidths IK' 2K' 3H' 8.9 8. 9. 12 8, 9. 10, 12.16 10 10 10 340 430 510 USG Metal Runners 1K'-2K'-3K' widths 12 10 283-339422 USG Metal Angle Runner Size 1K'*K* (2) 10 10 176 USG Furnng Channel 12 10 ! 320 USG Furnng Clip - 500 36 USG Adj. Wall Furring Bracket - 500 52 USG Lathing Channels--K' 16-20 lK'and2' 16-20 20 10 300 500-629 RC-1 Resilient Channel (2) 12 20 213 USG Wall Ties - 1000 35 USG Tie Wire (1) 501 coil 11) 25# hank 'll Aporoi. foeuff of rt: $71 ft: i$#|.--5.000 ft.; (2) Stt Chaactr 2 for pitfuct Otwriomn. 1.000 ft 0 S !o( ," CUPS AND SCREWS A complete line of specially formed steel clips and self-drill ing steel screws is available to provide positive attachment and rapid erection of USG gypsum plaster bases and metal lath. Various types are designed for use with different USG partition and ceiling systems. Bridjoint Clips provide a rigid alignment of Rocklath Plas ter Base where ends of lath do not fall on structural mem bers, thus adding crack resistance at vulnerable points; Clips: PRODUCTS 77 Brace-Tite Clips, of special wire, attach %' Rocklath to metal 061110? grillages, exterior wall and beam furring chan nels, and Trussteel Studs in partitions; Trus-LoK Clips at tach %' Rocklath to Trussteel Studs; USG Bracing Clips and Ceiling Runner Clips attach Long Length Rocklath to channels and runners. USG Resilient Clips provide a non-rigid or floating attach ment of H" Rocklath Plaster Base and USG Metal Lath to the structural frame, thus affording increased protection against plaster cracking due to structural movement, and increased sound resistance. BRIDJOINT FIELD CUP B-l is used to support and align end joints which do not fail opposite structural members; sizes for both % " and Vi' Rocklath. BRIDJOINT CORNER CLIP 8-2 is used in conjunction with B-l clips to eliminate nailing of Rocklath in intenor corners or angles; also when ceilings are resilient and walls nailed direct For %" Rocklath only. BRACE-TITE FIELD CLIP BT-1 is used for suspended ceilings, exterior wall and beam furring and hollow pipe chase parti tions. Provides support across full width of lath. For use with standard % ' cold rolled channels. BRACE-TITE STARTER CLIP BT-1 is used in conjunction with BT-1 field clip to start first course of lath. TRUS-LOK FIELD CLIP TL-1 is designed for attaching %' Rocklath Plaster Base to Trussteel Studs. TRUS-LOK STARTER CLIP TL-2 is used in conjunction with TL1 Clips, MS-1 Clips and runner track to start first course of lath. 78 PRODUCTS: Clips TRUS-LOK Drive-In Starter Clip MS-1 Clip USG 8raeing Clip CZ, Ceiling Runner Clip TRUS-LOK DRIVE-IN CLIP is used to anchor ID bottom course of lath in direct attachment to TRUSSTEEL Studs, and (2) top course of lath in partitions to underside of monolithic con crete flat slab or concrete joist filler construction: also as starter-finisher clip with Metal Stud-RocKLATH Partition. MS-1 CLIP serves for direct attachment of H" Rocklath to channel-type USG Metal Studs. USG BRACING CLIP is provided for attaching ^4" channels to 34' long length Rocklath as temporary braces in 2' solid Rocklath and plaster partition construction. CEILING RUNNER CLIPS are used for attaching Long Length Rocklath to "L" shaped ceiling runners. RESILIENT CLIP TR-1 attaches 34" Rocklath to TRUSSTEEL Studs spaced 16' o.c., furs lath 36' from stud face. RESILIENT STARTER-FINISHER CLIP R-SF is used with start ing and last courses of resiliently attached Rocklath Plaster Base on wood studs or Trussteel Stud snap-in runner track. RESILIENT CLIP R-l. for wood studs or joists spaced 16" o.c.. is attached by nailing with 13-ga., 134 ' lathing nail. Rocklath is floated 34 " free of framing members. RESILIENT CLIP R-2 is for internal angles of wood frame construction when both surfaces are resiliently furred. Furs lath 34' from framing. Clips: PRODUCTS 79 RESILIENT CLIP R-5 is used on masonry walls or for face attachment over sound deadening' board. Rockiath Plaster Base is resiliency furred out V4' from face of masonry or backing board. RESILIENT CLIP NO. 100 is used to resiliency fur %' cold rolled channels from 1V4 ' runner channels in suspended ceil ing construction. Alternate clips on each channel are reversed. Lath is furred 1 Vi' from runner channel. RESILIENT CLIP NO. 200 attaches Vi" pencil rods to wood studs or joists, thus floats metal lath H" free of framing members when lath is wire tied to rods. On walls, rods are snapped into clips; on. ceilings, clips are slipped onto rods. Clips are attached with 13-ga. lVi" lathing nails. RESILIENT CLIP NO. 400 is snapped over outer flanges of Trussteel Studs, 14' pencil rod is snapped into protruding tongue of clip, and metal lath wire tied in place Vi' from stud face. RESILIENT CLIP NO. 500 provides furring and resilient at tachment of metal lath on masonry surfaces. A Vi" channel is wire-tied inside protruding tongue of the clip and metal lath is tied to channel, thus is furred out %' from face of masonry. BB013 0244 80 PR00UCTS: Fasteners FASTENER SELECTOR GUIDE--ROCKLATH PLASTER BASES Framing Mai. Frame Spacing C. to C. Attachment Fastener Spacing C. to C. H" ROCKLATH Plaster Bas* wood 16' Nails--13 ga., 1ft' long. **Ai' flat head, blued 4 per Staples--16 ga. galv. flattened wire, flat 16' width crown 'At wide, ft' divergent legs of lath R-l & R-Z Clips 1 per 16' USG metal stud 16' Screws-USG 1', Type S 2 per 16" width. V from edges TRUSSTEEL stud metaf nailing stud ft' channel TL-1 clips 16' TR-1 resilient clips (& accessories) Nail or staple as recommended by 16' stud manufacturer 16' BRACE-TITE clips (4 accessories) 16' along stud 4 per 16* width 1 per 16'width USG metal furring channel Screws--USG I". Type S 16' 3 per 16' width, 1' from edges & center ROCKUTH Plaster Base wood 24' Nails--13 ga., 1ft 'long, "/it'flat head. blued Staples--16 ga. galv. flattened wire, flat crown 'At' wide, 1' divergent legs 5 per 16'width of lath FASTENER SELECTOR GUIDE-USG METAL LATH Framing Wood Studs Wood Joists Steel Studs, Channels or Rods Nailing Studs Attachment Fastener 1 Spacing | C. to C. Nails--4d common, driven to ft' penetration and bent over to engage 3 strands or through the rib Nails--l' roofing nail 'At' head, engaging 2 strands or through the rib 6' 6' Staples--1', 14 ga. wire staples, engaging 2 1 strands or a nb ! 6' Nails--1H'. 11 ga. barbed rooting nail. 'At' head, engaging 2 strands or a nb 6' No. 18 ga. be wire 6' Nail or staple as recommended by manufacturer of the member 6' Fasteners: PRODUCTS 81 US6 LATH ATTACHMENT CLIPS-PRODUCT DATA Product BRIOJOINT Clip B-l Clips Per IX Sq. Yds. Surface 0) ISO 350 Shipping Unit (Pcs.) H'-5X H'-4X wt./ MPcs. (Ujs.) 38 37 BRIOJOINT Clio B-2 BRACE-TITE Field Clip BT-1 (21 550-600(3) 750-800(4) 5X 55 500 55 BRACE-TITE Starter Clip BT-L (5) 5X 21 TRUS-10K Feld Clip TL-1 550-600 10X 26 TRUS-LOK Starter Clip Tl-2 TRUS-LOK Drive-In Clip MS-1 Clip (6) (6) 550-600 500 15 500 22 10X 22 USG Bracing Clip (7) 500 14 Celmg Runner Clip (8) 5X 10 Resilient Clip TR-1 Resil. Slarter-Fmsher Clip R-SF Resilient Clip R-l 550-6X (6) 550-600 250 68 250 22 250 68 Resilient Clip R-2 Resilient Clip R-5 (21 550-6X 250 68 200 64 Resilient Clip Np. IX (9) 500 56 Resilient Clip No. 2X (10) 5X 44 Resilient Clip No. 4X Resilient Clip No. SX (11) 500-510 10X 27 5X 78 (U QwMif baud on irud apaciftf of 16'o.c. uniots0ofw<M not*d.(2l I u. |fi'of anftaeoriiur. (3) H' chan. tram* 16# o.c. (4) H ' chan. from* 12* o.c. t5l l dtp at taeh eftao. tram# and jtartar iotn roncturo. (6) t ta. 16' at bottom oof* ot first courso-ma? bo uiod o top rtft of last court* --odapubto to varrtnf thckntists ot board. (7) l oa. lath at tomo. bractnc chaint*)--2 at oacn chan. ond. Ill 2 oa. laib. (9) 350 dips coo'd, with fornof cnan. 12' o.c--<75 dioa rac'd. wtn fur. eftsfl. 16' o.c (10) 600 roq'd. with dips soacod 16* o.c aloof stud--750 roo'd. with dips toocod 12* o.c *o| joist. (U) 775 roo'd. with dips spocad 12' o.c aloof stud--MO rop'd, with dips soacod 16' o.c aionf stud. USG SCREWS are the recommended means of attaching Rocklath Plaster Base in certain applications and are also used for attaching large-size Imperial Plaster Base and Red Top Radiant Heat Plaster Base. For application of single layer %' RocKLATH Plaster Baae to USG metal studs, or furring channel USG 1' Type S Bugle Head Screws are used. For attaching metal door frames to steel studs, USG %' Type S-12 Pan Head Screws are used; for steel studs to metal runners, USG H" Type S Pan Head Screws. See general screw data--pages 36, and 38. 0" 82 PRODUCTS: Basecoat Plasters BASECOAT PLASTERS AND APPLICATION Basecoat plasters are expected to be uniform, plastic and freespreading:. They must be easily mixed and must provide high coverage while setting to maximum hardness and greatest possible strength. For the beauty and durability of which plaster is capable, requirements should be followed as to the number of coats applied. Three-coat work is necessary on all metal lath and on edge-supported gypsum lath used in ceilings; three-coat work is desirable on all gypsum lath; two-coat work is ac ceptable on unperforated gypsum lath when properly sup ported and on masonry plaster bases (PykoBah Tile, rough concrete block, clay tile, or porous brick). In preparing for plastering, consideration should be given to the selection of materials not only for comparability but for the quality of the structure to be plastered. It is wise to upgrade plastering specifications when possible. Following are general recommendations listed in order of preference. No. 1 in each case can be expected to produce the highest quality results: BASECOAT PLASTER OVER METAL LATH Scratch Coat 1. STRUCTO-BASE (1) Plaster, sanded 100:2 Brown Coat STRUCTO-BASE Plaster, sanded 100:3 2. Wood fiber, neat or sanded up to 100:1 Wood fiber, sanded up to 100:1 3. Wood fiber, neat, or sanded up tp 100:1 RED TOP Gypsum Plaster, sanded 100:2 4. Wood fiber, neat, or sanded up to 100:1 STRUCT0-LITE Plaster (sand float finish only) 5. RED TOP Gypsum Plaster, sanded 100:2 RED TOP Gypsum Plaster, sanded 100:3 6. RED TOP Gypsum Plaster, perilled 100:2 RED TOP Gypsum Plaster. perilled 100:2 (sand float finish only) (0 Vtfrty varitoiJfty mtti rout local U.S.G. Safas raprataitiaova: S X BASECOAT PLASTER AGGREGATES OVER GYPSUM LATH (A i Select Plaster from Technical Data Chart according to requirements and aggregate preference below. 1. Sand 2. Mill-mixed perlite 3. Job-mixed perlite 4. Job-mixed vermiculite dote: Liintwwtht lurtfin xnnuW not bo uuU on i conjtructioa wboro sound isolation u i canMorotion. Basecoat Rasters: PRODUCTS 83 RED TOP Wood Fiber Plaster A gypsum plaster containing fine particles of selected wood fiber, normally requiring only the addition of water. When used over masonry or gypsum lath or as a brown coat on metal lath, 1 cubic foot of sand per 100 lbs. of plaster should be added. Wood Fiber Plaster can be applied to all standard lath and masonry surfaces and is recommended as a scratch coat for metal lath. Outside masonry walls should be furred prior to plastering to prevent seepage and condensation. Wood Fiber, neat, weighs approx, hi less than a sanded gyp sum basecoat, has nearly twice the compressive and tensile strength of sanded plaster and generally provides greater fire resistance than normally sanded gypsum plaster at a slightly higher cost. Complies with ASTM C-28 and Fed. Spec. SS-P-402 Type W. RED TOP Gypsum Plaster This is a gypsum basecoat requiring the addition of an aggre gate, to be used on approved plaster bases. It is supplied as either ftbered (recommended for scratch coat on metal lath) or unfibered, in three types: (1) REGULAR: use with sand aggregate, hand application. BB013 0248 84 PROOUCTS: Basecoat Plasters (2) LW: use with lightweight aggregate, hand application. (3) Machine Application: for use with sand or lightweight aggregate. When used with perlite aggregate and machine applied, vertical lift should not exceed 30 ft. and hose length 150 ft. All three comply with ASTM C-28 and Fed. Spec. SSP-40'2 Type N. STRUCTO-BASE Plaster Developing higher strength than conventional plasters, this gypsum basecoat plaster is highly recommended for such areas as schools, hospital corridors, handball courts, etc., or wherever a high-strength basecoat is needed. Complies with Fed. Spec. SS-P-402 Type N, and ASTM C-28, Gypsum Neat Plaster, including a strength requirement of 2800 psi min. STRUCTO-LITE Gypsum Plaster A mill-mixed perlite aggregate gypsum plaster that requires the addition of only water at the job site. It is formulated in four types: Regular--for use over gypsum lath, hand appli cation; Masonry--for use on high suction unit masonry base only, hand application; Regular for Machine Application-- for use over gypsum lath; Masonry for Machine Application-- for high-suction unit masonry. Structo-Lite weighs less than half as much as a sanded basecoat, provides three times the thermal insulation of sanded plaster and offers excellent fire protection. Over-all cost is comparable to job-mixed lightweight aggregate plas ter. Complies with ASTM C-28, Gypsum Ready-Mixed Plas ter. Same machine application limits as for Red Top Gypsum Plaster--perlite mix. Portland Cement-Lime Plaster Required for interior use where high moisture conditions exist such as steam rooms, dairies, showers, etc.; also used as an extenor basecoat for stucco. A Portland cement-lime plaster is prepared on the job in the following proportions: SCRATCH COAT: l sack Portland cement, 2 sacks USG Moktaseal Lime, 7Vi cu. ft. sand; 2 lbs. fiber (over metal lath or stucco mesh). BROWN COAT: l sack portland cement, 2 sacks Mortaseai. Lime, 9 cu. ft. sand. FINISH COAT: Oriental Exterior Stucco (mill-mixed) or a float or texture-finish plaster. ' With Portland cement-lime plaster, scratch and brown coats require cunng with water after set. Self-fumng metal lath must be used over smooth dense surfaces, gypsum lath or Basecoat Plasters: PRODUCTS 85 gypsum block. Control joints should be provided to compen sate for the shrinkage of the Portland cement piaster during drying. A Keenes Cement-Lime Putty Plaster cannot be used over a Portland cement basecoat. Application of RED TOP Basecoat Plasters. The piaster basecoat is the most important element of the plastered wall; therefore it is necessary to select the proper basecoat plaster and apply it in an approved manner. TWO-COAT WORK: over gypsum lath and masonry apply the basecoat with sufficient material and pressure to form a good bond to the base and to cover well; then double back to bring the plaster out to grounds, straighten to a true surface with rod and darby without the use of additional water, and leave rough to receive the finish coat. THREE-COAT WORK: apply scratch coat with sufficient mate rial and pressure to form good full keys on metal lath and a good bond on other bases, then cross-rake. After the scratch coat has set firm and hard, apply the brown (second) coat, bring out to grounds and straighten to a true surface with rod and darby without the use of additional water. Leave rough to receive the finish coat. Important Job Precautions EQUIPMENT AND STORAGE OF MATERIALS: all successful plas ter jobs require adequate equipment: mortar boxes, mortar boards, scaffolding and tools. Ample scaffolding should be provided to permit continuous application of both basecoat and finish plasters for a complete panel of wall or ceiling. Keep all mixing tools clean by washing in clean water only. To keep stored plaster dry, stack on planks raised off ground and away a from damp walls or floors. (0 O u HEATING: plaster must not be applied to surfaces that con tain frost. A minimum temperature of 55* F. should be main- O tamed for an adequate period pnor to, during, and after Jj 1 -f T 36 PRODUCTS: Basecoat Plasters application of the plaster. In cold, damp or rainy weather, properly regulated heat should be provided but precautions must be taken against rapid drying before set has occurred. This prevents "dry-outs." VENTILATION: As soon as the plaster has set, free circulation of air should be provided to carry off excess moisture and pre vent "sweat-outs." After piaster has set, heating should be continued to insure as rapid drying as possible. In hot, dry weather, protect the plaster from wind and from drying un evenly or too rapidly before set has taken place. If glazed sash are not in place, exterior openings m the building should be screened with cheesecloth or similar material. Application over Concrete SURFACE PREPARATION: monolithic concrete surfaces should be brush-cleaned of all dust, loose particles and other foreign matter. Remove all laitance and efflorescence by washing with a 10% solution of commercial muriatic acid and water, then rinsing well with clear water. Remove grease or form oil by wiping with naphtha spirits. A high-quality plaster bonding agent should be applied to all surfaces according to manufac turer's directions. BASECOAT PLASTERS-TECHNICAL DATA Product and Mix Com pressive Strength Psi-- Ory(l) Coverage/Ton Plaster Weight Bag (Sq. Yds.)(2) Lhs./Cu. Size Gypsum Metal Unit Ft.--Ory (Lbs.) Lath Lath Masonry STRUCTO-LITE (regular) Wood Fiber neat Wood Fiber (sand) 100:1 STRUCTO-BASE (sand) 100:2 IMPERIAL (Basecoat) neat RED TOP mixed vnm- (Sand) 100:2 100:2tf 100:3 (Perlite) 100:2 100:3 600-800 1500-2000 1200-1600 2800-3200 3000-4000 750-1100 650-850 550-750 600-800 450-600 50 82 97 124 107 107 108 109 48 41 80 135-145 70-80(3) 130-140 100 85-95 45-55 100-110 100 125-145 65-75 100-110 100 90-105 155-170 80 360-470 300-400 200-220 105-120 175-190 50to 100 180-190 80-95(3) 145-155 (1) Awiii laooratory Tt Results, Fiauras mss vary miner for products from moiviOMl pums. Tssim m accorosncs witn ASiM cart. tie (Z) Grounds Ondudint fntisA coal)' Grosum lain--14* rtaca of lath), mom lain--(back . of lam), unit masonry-- H*. IMPERIAL Plnraf--J/o` |SS (1) ij|Mrotfnt aurtfatoo plasters ara not rocammonosO ouor motat latn wnan tno ftnnn coat TCU. it to to smoM* trow*to. 2k Finish Plasters: PRODUCTS 87 VENEER PLASTERS Today's plastering includes: high-strength veneer plasters-- Imperial Plaster Basecoat with Diamond Plaster Finish (an extra hard finish) and specially fortified heat-resistant Red Top Radiant Heat Plaster. See Chapter 2 for complete de scription and application of these products. FINISH PLASTERS AND APPLICATION Finish plasters serve as a leveling coat over the basecoat to provide a durable surface with the required resistance to abrasion. Some finishes are used as a base for decoration while others provide the final finished surface themselves. There are several types of gypsum finish plasters, some re quiring the addition of water only and others which are a blend of gypsum, lime and water, or of gypsum, lime, sand and water. They are selected according to job requirements for texture, color, hardness, sound absorption and for compatability with the basecoat. Since the finish plaster coat comprises about 75% of the visible room area, it is important to select high-quality mate rials, mix them properly and use according to directions. BB0I3 0292 88 PRODUCTS: Finish Plasters USG FINISH PLASTERS--TECHNICAL OATA Product Gauging Wt. Sq. Yds. Finish Physical to Lime, per per Ton Texture Properties (Dry Wt.) Bag (1) ORIENTAL Interior Finish Float or Texture Finish Hard and Resistant to Abrasion neat 100 250-300 V,' STRUCTOGAUGEand Lime Putty Smooth Trowel Extremely Hard and Resistant to Abrasion 100 lbs. gauging 100 lbs. lime 100 300-375 50 Hard and Resistant to Abrasion 100 lbs. gauging 200 lbs. lime 100 335-400 50 DIAMOND Finish Keenes CementLime Putty Smooth T rowel Smooth Trowel Hard and Resistant to Abrasion Hard and Resistant to Abrasion neat 400 lbs. Keenes 100 lbs. lime 50 390-445 100 260-340 50 Med. Hard and Re sistant to Abrasion 200 lbs. Keenes 100 lbs. lime 100 285-400 50 Gauging Plaster Lime Putty Smooth Trowel Standard SO lbs. gauging 100 lbs. lime 100 390-465 so Keenes Cement. Lime Putty and Sand Float Finish Gauging Plaster, Lime Putty and Sand Float Finish ORIENTAL Extenor Stucco Float or Texture Finish Hard Standard Extremely Hard and Resistant to Abrasion 100 lbs. Keenes SO lbs. lime 400 lbs. sand SO lbs. gauging 100 lbs. lime 400 lbs. sand neat 100 250-300 so 100 250-300 50 100 150-200 Vi' (I) 'At' to** ticwt u Mlad MONOTRON SURFACE HARDNESS-GAUGING PLASTERS i KilotnfM rtotrd to fore* 10 mm. aumttw it--t bail 01* into oiasttr rc*> Gauging/Lime Ratio 1:4 1:2 1:1 2:1 4'1 STRUCTOGAUGE 27 48 105 162 206 Regular Gauging 24 34 51 74 96 Bold lacad laocoto roeommondM propo/licmn|. Keene's Cement or ' Regular 14 Quick-trowel O' -19 19 25 27 37 34 51 ff-.i 40 S3 S3 Finish Plasters: PROOUCTS 89 TROWEL FINISHES: used where a smooth, easily maintained surface is desired, often as a base for paint or other wall coverings. The degree of hardness, porosity, and polish is determined by the materials and application techniques used. When a smooth-trowel gauged lime putty finish is used over a basecoat containing lightweight aggregate on any plaster base, it is necessary to add at least SO lbs. of fine silica sand or V4 cu. ft. of perlite fines per 100 lbs. of gauging plaster to improve the comparability of the finish with the basecoat. FLOAT OR SPRAY TEXTURE FINISHES: provide pleasing, dur able finishes where surface textures are desired. They are recommended over all types of gypsum basecoats and are the most desirable finishes from the standpoint of crack-resist ance. The surface texture is easily controlled and can be produced by spray application, power float, or a variety of hand tools. OTHER TEXTURE FINISHES: many pleasing and distinctive tex tures are possible using various techniques in finishing. Fin ishes may range from an extremely fine stipple to a rough, heavy or course texture. Variety is limited only by the imagi nation of the designer or the ingenuity of the applicator. ORIENTAL Interior Finish This is a factory-prepared white finish containing properly graded aggregate to insure easy-working qualities and uni formity in results. It requires no further decoration and may be applied to produce many types of surfaces ranging from very fine sandfloat finish to a heavy texture. It is highly resistant to abrasion because of its great hardness and is uniform in color. To eliminate need for further surface deco ration, color may be added to the plaster mix. Mixing and Application Add clean water only and hoe the plaster into the water. Allow to soak 20 or 10 min. and mix thoroughly to a smooth, creamy, easy-working consistency. This plaster must be ap plied to a set, "half-green" basecoat of gypsum plaster. If the BB013 0294 A i 90 PRODUCTS: Finish Plasters basecoat is exceptionally dry, it should be sprayed uniformly with clean water the night before finishing. Apply by hand in a two-coat double-back operation. Scratch in a thin coat well ground into the base and double back with a second coat, filling out to a true, even surface. The surface can be floated with a sponge, sponge rubber or carpet float. Do not use water while floating. The finish can be applied in any desired texture except a smooth trowel finish: also can be spray-applied. For uniform appearance, spray finishes must be applied over a smoothly troweled level finish plaster surface. * \ * ; i : DIAMOND Finish Plaster A new pre-mixed interior finish that provides exceptional surface hardness, greater crack resistance and excellent trowelling features. See Chapter 2 for complete description and application. ~ ^ RED TOP Concrete Finish Mill-prepared plaster for leveling and texturing interior monolithic concrete surfaces which have been treated with a highquality bonding agent for bonding gypsum plaster or gauged lime putty directly to interior monolithic concrete surfaces. Red Top Concrete Finish is an exclusive spray-textured finish that is economical both in initial cost and application. The spray-on coat eliminates need for further decoration. i * 51 | ? ^ | i Exterior Stucco: PRODUCTS 91 Mixing and Application Mix Red Top Concrete Finish using clean water and clean equipment. Machine-mix to a thin consistency and allow to stand a minimum of 30 min. Re-mix to a smooth consistency before using. Concrete Finish can be soaked the day before use, if desired, and remixed to a plastic consistency just be fore using. Use highly gauged mix (approx. 20% Red Top Gauging) to fill in and level deep irregularities and allow to set. For the leveling coat, gauge (approx. 15% Red Top slow-set Gaug ing) only sufficient material to permit application and final troweling in 20 to 25 min. Grind a thin coat into the bonding agent and previously ap plied fills, and double back for a level surface. Trowel two or three times to a level surface. SPRAY TEXTURE FINISH: allow leveling coat to dry before applying spray texture. Mix Red Top Concrete Finish to a creamy consistency, using clean water only. In applying, use a hand texturing gun, or small mechanical texturing machine having an orifice size and air pressure sufficient to produce a fine, uniform texture. Spray all areas in a uniform pattern, crossing surface in four directions (up and down; side to side). Allow Concrete Finish to dry naturally; furnish heat and ventilation in cold or slow-drying weather. ORIENTAL Exterior Stucco Oriental Exterior Stucco is a pre-mixed, water-resistant fin ish for use over exterior Portland cement-lime basecoats only. This material is available in 10 designer colors and white for hand application. Use only white for spray application. It is suitable for application on new work or for remodeling and is an economical means of beautifying in two ways: with tex ture and color. , Machine spray Dashed and troweled  92 PRODUCTS: Exterior Stucco This finish is plastic, easy to apply and permanently durable and can be worked in a number of textures: rough coat, stipple, sponge or fine-grained float finish. Mixing and Application HAND APPLICATION: Oriental Exterior Stucco needs only the addition of water for mixing. Use clean water and meas ure accurately. Do not add anti-freeze, waterproofing com pounds or sand. Hoe the stucco into the water and allow to soak approximately IS min. Then hoe thoroughly to a smooth consistency. Mix each batch for the same length of time to in sure color uniformity and mix only enough material for 3 hours' use. "2:.- Spraying Portland cement base for ORIENTAL Extenor Stucco Apply Oriental Exterior Stucco only over a Portland cementlime and sand basecoat that is level but left rough under the darby, or broomed and properly cured. Water-spray basecoat to provide a uniformly damp "half-green" surface. Remove loose and projecting particles from the basecoat. Then apply i a thin coat well ground into the base and completely covering 1 it Double back and fill out to a uniform surface about hi' thick, covering total area in one operation to eliminate join ings. Trowel three or four times before starting to texture. For a float finish, use a cork, wood, carpet or sponge rubber float and work the surface to an even texture, free from blemishes, as the material stiffens and starts to set. Floating. must be done without the use of additional water. Gauging Plasters: PRODUCTS 93 MACHINE APPLICATION: Oriental Exterior Stucco (white only) may be applied in a single-coat or two-coat operation. Excessive mixing water should not be used as this may result in "lime bloom." One-Coat Application: Spray-apply material to basecoat to uniform thickness of approximately hi". Work from wet edges to complete an entire unbroken area in one continuous operation to eliminate joinings. Two-Coat Application: Apply first coat with a trowel as in hand application. After troweling uniformly level, apply tex tured second coat by machine-spraying to a total thickness of approx. V4". After setting, fog-spray surface with water periodically for several days to cure the finish and help to prevent glazed spots and "lime bloom." Apply as much water as is readily absorbed. The frequency of spraying will depend on the weather. GAUGING PLASTERS AND APPLICATION Lime, when used alone as a finish plaster, does not set, is subject to shrinkage when drying and lacks a hard finish. Therefore, gauging plaster is blended into the lime putty in the proper proportions to provide controlled set, early hard ness (see Monotron Surface Hardness table page 88) and strength, and to prevent shrinkage cracks when used as a finish coat. High-strength Keenes and USG StructO-Gauge Gauging Plaster are to be used only over sanded or wood fiber basecoat piasters. Over lightweight aggregated basecoats use white or regular gauging plaster that is properly aggregated. BB013 029B USG GAUGING PLASTERS-TECHNICAL DATA Product CHAMPION (wmtt) STAR (white) RED TOP Gauging (local-gray) RED TOP Gauging (local-gray) RED TOP regular Keenes Cement (white) RED TOP quick trowel Keenes Cement (white) STRUCTO-GAUGE (white or light gray) Set Time with Lime Putty (Min.) quick set 20-30 slow set 40-60 slow set 45-60 quick set 20-30 160-360 60-120 slow set 60-75 quick set 30-40 Sag Size (Lbs.) 100 5G 100 50 100 100 300 so 100 50 100 94 PRODUCTS: Gauging Plasters CHAMPION, STAR and RED TOP Gauging Plasters Red Top Gauging Plasters are carefully ground and screened to proper particle sizes to make the plasters quick-soaking and easily blended with lime putty. Champion (quick-set) and Star (slow-set) are white gauging plasters for finish work. Red Top Gauging is slightly darker in color and is available in quick-set (QS) and slow-set (SS). These plasters are also available with added perlite fines and are designated as `Qual ity," for use over lightweight aggregated basecoat plasters. Mixing and Application Add gauging plaster to lime putty in proportions of 1 part dry gauging plaster by weight to 2 parts dry lime by weight or 1 part dry gauging by volume to 3 parts lime putty by volume. To mix, form a ring of lime putty on the mixing board. The volume of putty used depends on the wall or ceiling area to be covered. A hod of lime putty weighs approximately 100 lbs., a 12-quart bucket of lime putty about 35 lbs. (50 lbs. dry lime equals 100 lbs. lime putty). After forming the putty ring, pour clean water into the center of the ring in correct proportions: 6 qts. of water to 100 lbs. of lime putty: 2 qts. of water to each 12-qt. bucket of lime putty. Next, sift "slow" or "quick" set gauging plaster into water; 25 lbs. gauging plaster to one hod of lime putty. Thoroughly wet the gauging plaster and blend the materials thoroughly to prevent gaug ing "streaks" and provide uniform density. +<4uA (*** Gauging Plasters: PROOUCTS 95 To protect against finish coat check or map-cracking, add % cu. ft. perlite fines or 50 lbs. silica sand to every 100 lbs. of gauging used. This addition is necessary when applying smooth troweled finishes over lightweight aggregate basecoats. Mill-aggregated "Quality" gauging plasters are gener ally available and eliminate the need for on-the-job measuring. Apply the gauged lime putty over a partially dry basecoat. Scratch in a thin coat, well ground into the basecoat, and double back with a second coat, filling imperfections. After the basecoat has absorbed most of the excess water from the finish, trowel to densify the surface. As final set takes place, water-trowel the surface to provide a dense, smooth surface. j STRUCTO-GAUGE Gauging Plaster | This is a new, high-strength gypsum finishing plaster designed for use with lime putty to produce an easily applied finish of extreme hardness. It is available in "Quick Set" (30 to 40 min.) and "Slow Set" (60 to 75 min.) and complies with ASTM C-28 for gypsum gauging piaster and Fed. Spec. SS-P402 Type G and has the added property of a compressive j strength of at least 5000 lb. psi when tested in accordance ' with this specification. Finish hardness may be altered by varying the proportions of lime putty and Structo-Gauge. Since the material cannot be retempered, use regular Keenes Cement when retempering is a factor. Structo-Gauge may be used for wall and ceiling finishes as in residential bathrooms, kitchens and where sur faces of extreme hardness and durability are required such as hallways or traffic areas in hospitals or schools. It is not recommended for use where excessive or continued moisture conditions exist. Application must be over high-strength sanded or wood-fibered gypsum basecoats or Imperial Basecoat only. ' : ' | i' ' Mixing and Application For a "hard finish," mix in proportions of 100 lbs. dry hydrated lime (200 lbs. of lime putty) to 100 lbs. StructoGauge. For a "medium hard" finish, mix in proportions of 200 lbs. dry hydrated iime (400 lbs. of lime putty) to 100 lbs. Structo-Gauge. CB Apply like regular gauging over a partially dry gypsum 5 basecoat. Scratch in the thin coat, well ground into the base, M and immediately double back with second coat, filling imper- (J fections. Water-trowel to a smooth, hard finish, free of all blemishes. Continue troweling until final set has taken place. S Clean tools and equipment after each mix. q, O 1 96 PRODUCTS: Finish Limes RED TOP Keenes Cement A high-strength white gypsum plaster used with finish lime putty for extremely hard, dense surfaces. It is the only gyp sum plaster that can be retempered. Made in two types: Type I or regular, slow setting (3-6 hours) : Type II or quick troweling, setting (1-2 hours). Quick-troweling Keenes must be used with a minimum of 25 lbs. dry hydrated lime per 100 lbs. of Keenes. Both products comply with ASTM C-61 and Fed. Spec. SS-P-00410 Type I and II. Keenes Cement-Lime Finish is similar in many respects to a lime gauged finish except that Keenes Cement, instead of gauging plaster, is used in varying proportions depending on the hardness required and is generally used as a float finish. If a smooth trowel hard finish is desirable, use StrcctoGaUCE Gauging Plaster. Keenes Cement is for interior use over sanded or wood-fibered gypsum basecoats. Do not apply smooth troweled finish over lightweight aggregate basecoats. Mixing and Application KEENES CEMENT-LIME FINISH: for medium hard finish, mix in proportion of 100 lbs. lime putty (50 lbs. of dry hydrated lime) to 100 lbs. Keenes Cement. For a hard finish, use 50 lbs. lime putty (25 lbs. of dry hydrated lime) to 100 lbs. Keenes Cement. Apply the finish coat over a set basecoat that has been broomed and is partially dry. Spray with water if surface is too dry but do not soak. Scratch in a thin coat and then double back with a second coat to a true surface. Trowei with water to a smooth, glossy finish, free from blemishes Continue troweling until finish has set. . ; I , ; . SAND FLOAT FINISH: a commonly used, hard float finish which may be satisfactorily colored. Mix in proportions of 100 lbs. Keenes Cement to 50 lbs. dry lime and 400 lbs. sand, with or without lime-proof colors. Apply in same manner as indicated for Keenes Cement-Lime Finish but instead of the final troweling, use a wood, cork, sponge or felt-covered float to bring the sand particles to the surface to produce a pleasing, durable sand finish. : ' * ? . J FINISHING LIMES AND APPLICATION The purpose of finishing lime is to provide bulk, plasticity and ease of spread for the finish coat. Made from specially selected limestone of high purity, the most popular limes come from the dolomitic fields in northwestern Ohio. Finish lime produced in this area has excellent working qualities and is widely demanded. There are three types of finishing limes: (1) double hydrate, (2) normal hydrate, and (3) quicklime. Each material re quires different handling for slaking or soaking in order to produce a good finishing lime putty. 9: S u Finish Limes: PRODUCTS 97 Brand FINISH LIMES-TECHNICAL DATA Type Material U.S.G. Mlg. Mill Size Contain* Approximate Putty Preparation Coverage Per Ton IVORY DOUBLE HYDRATED FINISH LIME Dolomitic Ooubie Genoa. Ohio Hydrjte 50 lbs. Nona (list immadiately) HYDRATED FINISH LIME GRANO PRIZE Dolomitic Hydrate Genoa. Ohio 50 lbs. Soak IS hrs. RED TOP Dolomitic Hydrjte Genoa. Ohio SO & 25 lbs. Soak 16 hrs. RED TOP High Calcium Hydrate New Braunfels, Texas 50 lbs. Soak 16 hrs. 500-700 Yds. 500-700 Yds. 500-700 Yds. 500-700 Yds. FINISH QUICKLIME High New RED TOP Cataum Braunfels, Quicklime Texas 50 lbs. Soak 16 ha 800-1000 Yds. IVORY Double Hydrated Lime ___ This finishing lime immediately develops high plasticity when mixed with water and does not require overnight soaking. It mixes easily by hand or mechanical means, is easy to apply and has excellent spreading qualities. Ivory Double Hydrated Finish Lime is over 92% hydrated and eliminates harmful delayed hydration, expansion and separation in walls. This material, properly gauged and troweled, produces a hard, glossy finish. It complies with Fed. Spec. SS-L-351 Type F and ASTM C-206 Type S. Mixing and Application Machine mixing equipment must be eiean. Place 5% to 6 gal. clear water per 50 lb. bag of Ivory Hydrated Lime in mixer. BB0I3 026 98 PRODUCTS: Finish Limes Using a mocor-driven, propeller-type mixer, the complete mixing of lime putty takes 2 to 3 min. and results in a highquality, easy-working putty. Machine-mixed putty is plastic and coverage is increased from 10 to 15%. With a paddletype mixer, the mixing time is about 15 min. HAND-MIXING: for immediate use, place 5H to 6 gals, of water per 50 lbs. Ivory Double Hydrated Lime in mixing box. Add Ivory Lime to water and hoe sufficiently to eliminate lumps. Screen putty through an 8-mesh screen before using. OVERNIGHT SOAK: place water hose in bottom of a level soak ing box. Run water continuously while sifting Ivory Double Hydrated Lime through screen into water. When lime is soaked in this manner, there should be a small amount of excess water over top of lime. If excess water remains on the sur face the following morning, absorb excess water by screening in additional Ivory Lime, allow to soak a few minutes, then blend into putty by hoeing. RED TOP and GRAND PRIZE Hydrated Limes These finishing limes are hydrated during manufacture so that only the addition of water and soaking are necessary to bring material to full plasticity. They are economical, easyworking, uniform, white and plastic. Both products conform to Fed. Spec. SS-L-351 Type F and ASTM C-6, Type N. Mixing and Application MACHINE MIXING: produces a smoother more plastic putty, easier to use and with better coverage. Use approximately 6 gai. of water to each 50 lb. bag of Red Top or Grand Prize Hydrated Finishing Lime. Mix lime and water to a soupy consistency and then pour into soaking box. Soak mix for a minimum of 16 hrs. to develop maximum workability and plasticity. Screen mix through 8-mesh hardware cloth to assure smooth, lump-free putty. HAND MIXING: slowly sift Red Top or Grand Prize Hydrated Lime into water in soaking box. Allow material to take up water for about 20 to 30 mm. and then hoe briskly to mix thoroughly. Let mix soak for minimum of 16 hrs. to develop full workability and plasticity. For use, screen through 8 mesh hardware cloth and mix with desired gauging piaster that meets job requirements. RED TOP Finish Quicklime A high-calcium finishing lime. Red Top Finish Quicklime pro duces lime putty that is very plastic and economical to use because of its greater yield. It requires 16 hrs. of soaking and must be handled carefully to prevent burns or clothing dam age. Meets Fed. Spec. SS-Q-351 Type C and ASTM C-5. E9EO c io a a Finish Limes: PRODUCTS 99 Mixing and Application In slaking Red Top Finish Quicklime, use approximately 15 gals, ciean water per 50 lbs. quicklime and 18 gals, per 60 lbs. of quicklime. Sift quicklime into the water and hoe immedi ately, working thoroughly and breaking up all hot spots. Con tinue hoeing until boiling action stops (about 15-20 min.) and then run material into a water-tight aging box. Soaking or aging of slaked quicklime is necessary to insure complete slaking of all particles, to permit putty to cool be fore mixing, to develop its full plasticity and to permit the putty to stiffen for easier hodding to gauging board. Allow finely ground and pulverized quicklime to soak at least 16 hrs. before using. Select proper gauging putty for job requirements and mix with the Red Top Finish Quicklime putty. Hot and Cold Weather Precautions--Finish Lime IN COLD WEATHER: a few precautions will result in improved quality and easier working. Where weather and water are cold, lime develops better plasticity when soaked overnight. The best conditions are a warm room and water over 50* F. It is important to note that in cold weather the lime puttygauging mixture requires a longer time to set. Therefore, gauging content should be increased or quick-set gauging added to offset the slower setting time. Proper heat and ventilation are musts. Windows should be opened slightly so that moisture-bearing air moves out of the building. Fast drying after setting is essential to a hard finish. Many cold weather problems with finish lime are a direct result of improper basecoat conditions. Finish should go over a set, fairly dry basecoat. Since the basecoat will dry slowly in winter, heat and ventilation are needed. The water retentivity of lime putty, plus a cold, "green" base, does not pro vide enough suction to remove excess moisture. Blistering and cracking can occur due to slow set or the lime may work back through set of the gauging. IN HOT WEATHER: precautions include proper soaking of lime putty. When the sun is hot, hydrated lime requires H to 1 gal. more water per 50 lbs. The water should be cool--not over 60*F. Soaking of putty in shade prevents undue water evaporation and helps to prevent curdling and loss of spread ing properties. Avoid soaking for periods longer than two or three days. For application of lime putty-gauging finish plaster, make sure that basecoat is set and partially dry. If applied over a dried out basecoat, water will be drawn from the finish coat resulting in severe check-cracking. Spray the basecoat before finish coat application and trowel finish coat until final set. BB0I3 0264 100 PRODUCTS: Acoustical Plasters ACOUSTICAL PLASTERS The main function of acoustical plaster is to absorb sound and reduce noise level. A wide selection of pleasing: finishes combined with medium to high light reflection is available. Low in initial cost, they provide greater sound absorption per dollar than most other commonly used acoustical materials. Basically mineral, they are incombustible and provide an added measure of fire safety whenever used. \ ' : ' ' USG ACOUSTICAL PLASTERS-TECHNICAL DATA Product HI-LITE Finish stippled stipple perforated NRC (1) .60 .60 Light Reflectance (2) 30% 77% Bag Size (Lbs.) 10 Coverage/ Ton (Sq. Yds.)(3) 250-290 AU0IC0TE machine textured .55 Satin White 65% Spec. White 70% 33 350-400 (I) Now reduction coortictool-- from sundard rests si s rocoimzod lioorstory. Csrs must o tikon to mix th mstonsl to soocjhod consisianctes and xpoiy lo uniformly full iroufldx. 3(?) U|ht rttloctsiKs iron ttsti it so iMoooMont roeoinuod isooratory. ( ) Co*ota(o oaiao on Vi* thicknou; amounts snown ttl wary oaoandmi upon mathod at application. Whan oroarmf, spoeity application motftod and sq. yds. to ba coworad. Stippled Stipple-perforated Machine textured HI-L1TE Acoustical Plaster This lime base acoustical plaster is pure white, making it particularly suitable for use in schools and office buildings where light rerlectance is of importance. It can be used in areas of high humidity because of its high moisture re sistance; also resists spreading of rust stains. Hi-Lite plaster develops its acoustical properties by mechanical opening of the surface by stippling and perforating. When perforated, this acoustical piaster can be painted without loss of sound absorption qualities. Mixing and Application Mix by machine. Add approx. 33 qts. water per bag of HlLm Plaster and mix until mortar weighs 15 to 17 lbs. net per 12-qt. pail (about 10-15 min. depending on muter speed). Prepare 1 hour's supply of plaster at a time. Acoustical Plasters: PRODUCTS 101 Stippling HI-LITE Acoustical Plaster Perforating is done after stippling Application over metal lath, gypsum lath or masonry bases (except monolithic concrete) requires a full scratch coat and brown coat of gypsum plaster that has been cross-raked. Where basecoat resistance to high humidity is required, USG Hi-Lite Acoustical Plaster may be applied over a full, crossraked Portland cement-lime basecoat. For the first coat of acoustical plaster, apply over a set and dry, partially dry or semi-``green" basecoat. Scratch in hard H' and double back to a total thickness of H". Use a wood or serrated metal darby for a true, uniform, roughened surface and allow plaster to dry overnight. Apply finish coat tt ' thick, working from wet edge to avoid joinings. STIPPLE FINISH: after surface sheen has disappeared (15-30 min.), stipple with a rice root stippling brush. Work on areas around doors and windows first since they dry faster. PERFORATING: for a stipple-perforated finish, perforate about 30 min. after stippling (when surface is hard enough to give clean perforations). Use perforator with stainless steel prongs and hold so that prongs are at right angles to plaster surface. Perforate about 3/16' deep, 500 per sq. ft. AUDICOTE Acoustical Plaster A low-cost material for machine or hand application, used over properly prepared gypsum or Portland cement basecoats, eo monolithic concrete or stable, prefabricated concrete units. O Available in Satin White and Special White, the uniform texture when spray-applied is ideal for use on large continuous u surfaces. It is fire-resistant, may be decorated with minor re oduction in sound absorption and can be economically refinished N with a spray coat of Ausicotc. S. I. i ; 102 PRODUCTS: Acoustical Plasters Mixing and Application MACHINE MIXING is the recommended method. For first coat, use about 55 qts. clean water per bag of Audicote. For ma chine-applied finish coat, use more water--70 to 90 qts.--de pending on machine used and finish desired. More water pro duces a finer texture. For hand-applied finish coat, mix with about 55 qts. water per bag. Add plaster to water and mix for at least 5 min. HANO MIXING: requires about 48 qts. water per bag. Hoe the mix to develop even consistency, free of lumps. MACHINE APPLICATION: apply first coat 7/16" thick, level with darby and point up with trowel for a smooth, even coat. Allow to dry partially and apply 54" thick finish coat. HAND APPLICATION: for the first coat, apply Audicote H" thick. Level with darby to smooth, level base, allow to dry partially and apply 54" thick finish coat. After finish coat has taken up sufficiently, it may be stippled, stipple-perforated, floated, darbied or troweled for the desired finish. Painting Acoustical Plasters Remove dust and dirt with vacuum cleaner. First coat: 1 part Texolite Standard Paint to 1 part water by volume. Second Coat (if required): 1 part Texolite Standard Paint to 2 parts water by volume. Use Binks Model 18 spray gun-66 SS (.070 onfice) with 30-40 lbs. pressure in gun and 20-30 lbs. on paint. Hold nozzle 14' to 18' from work and cover in one pass. Allow overnight drying between coats or longer in humid weather. SPECIAL PLASTERS U.S.G. produces a number of special plasters, among them Red Top Moulding Plaster and Rn> Top Casting Plaster. .. USG SPECIAL PLASTERS-TECHNICAL DATA Product RE& TOP Moulding Plaster RED TOP Casting Plaster Bag Size (Lbs.) 50 100 100 Approx. Cu. Ft. per 100-ib. Bag 1.3 1.5 Special Plasters: PRODUCTS 103 RED TOP Moulding Plaster Used for specialized work such as ornamental trim or run ning cornices, the grind of Red Top Moulding Plaster is very fine, to bring out details when used neat for cast work. For running cornice work, add a small amount of lime putty to add plasticity and to act as a lubricant for the template. RED TOP Casting Plaster Red Top Casting Plaster is like moulding plaster but has finer particle size. This gives smoother castings--important in casting fine plaques and art statuary. It is highly plastic and has great surface hardness and strength. For mixing, add only water. RED TOP Partition Tile Cement This is a specially prepared gypsum cement, used with sand and water, for setting interior partition units of Pykobab Gypsum Tile or clay tile. Red Top Partition Tile Cement makes an easy-working, economical mortar for column fire proofing coverings. It provides definite set, fine bedding and early high-strength qualities that insure strong, rigid joints for any non-load bearing partition. MIX RED TOP PARTITION TILE CEMENT in a clean mortar box. Use 1 part cement to 3 parts sand by weight and add clean water to bring to the right working consistency. Add sand to comply with ASTM Specs. Do not retemper tile mortar. RED TOP Retarder and RED TOP Accelerator Red Top Retarder and Red Top Accelerator are available for use with plaster when required by job or climate conditions. When used in excess, setting and drying problems can arise. Avoid especially use of too much retarder which can weaken the plaster finish. SOUND CONTROL PRODUCTS Adequate sound control is one of the fastest growing require ments in today's buildings. The public has become sufficiently "noise-conscious" to demand effective measures to control unwanted sound in both commercial and residential construc tion. With its advanced research, U.S.G. has been a leader in developing new systems and products for efficient, low-cost 2 sound control for plastered walls and ceilings in all types of new construction and remodeling. (J THERMAFIBER Sound Attenuation Blankets O These are semi-rigid, paperless, spun mineral fiber blankets O of uniform dimension and controlled density. When inserted i ................................... ............. 104 PRODUCTS: Sound Control Products in the partition cavity from floor to ceiling, these blankets help provide excellent Are ratings and substantially increase STC ratings of partitions. Sound Attenuation Blankets in partitions in some assemblies obtain an STC rating as high as 55. THERMAFIBER Insulating Wool (Regular) Blankets These blankets consist of mineral fibers mechanically formed into a uniform mat of definite dimension and controlled den sity. One side is enclosed with a strong asphalted paper which also forms nailing flanges. The breather side is enclosed in a durable fire-resistant, porous kraft paper; open-faced batts are available if required. This is a top-efficiency product pro viding an STC rating as high as 56 for sound isolation m partition systems. See Chapter 4 for sound test data. THERMAFIBER Blanket Data Type Thickness Sound Attenuation l'lVi'ori* Regular 2'or 3' NOTE: Chtch locti conOittoni lor pacajg* Width (Inch) 16 or 24 15. 19. or 23 jnd content. Length (Feet) 4 4. 8. or 24 USG Wood Fiber Sound Deadening Board A Vt" thick, 4' wide, low-density board, it is used with R-5 clips, Rocklath base and plaster to reduce sound transmis sion through a partition. This structural board is nailed to 2x4 wood studs and provides a resilient base for the R-5 clips. Limited to interior uses only. Lengths: 4', 8', 10' and 12', packaged: 6 pcs. per bdl., weight: 750 lbs. per M sq. ft. PAINT PRODUCTS USG Paints comprise a complete line of latex, alkyd, oil and texture products specially formulated for plaster and other surfaces--made by the company that knows walls and ceilings best. Included are sealers, primers and other surface prepa ration products; interior flat finishes, matching enamels and texture paints that are especially effective on veneer plaster ceilings. Recommended applications to plaster are listed in the Selector Guide on following page. o-i+iAvv Alt** Paint Selector: PRODUCTS 105 SELECTOR GUIDE TO USG PAINT PROOUCTS Type of Finish Desired Special Surface Treatment New Work | Redecorating PLASTERED INTERIOR WALLS Finish Product -- Description Thinners Method Application Hours One Gal. Drying Tima Coverage Touch | Recoat (Sq. Ft.) Velvet Flat Flat Semi Gloss Gloss (posy Glare TEXOLITE Primer Sealer TCXOlllE Primer Sealer TEXOLIU Primer Sealer USG Alkyd Primer Sealer USG Alkyd Primer-Sealer USG Penetrating Sealer None None None USG Alkyd Enamel Undercoal USG Alkyd Enamel Undeicoat ACREPOX Finish GRAND PRIZE Latex Wail Paint PRO KYD Alkyd Flat NR/w NR/ms Bl. Rl. SI Rl. SI. Bl USG Alkyd Flat Enamel USG Satin-lustre Enamel DIAMOND lustre Enamel ACREPOX Finish NR/ms Bl. Rl. SI NR/ms SI, B2. R2 NR/ms SI, B2, R2 SS/USG SI. B2, R2 Vt 1 t 3 3 4 24 450 24 400 24 400 24 450 500 24 450 8 190 220 PLASTERED INTERIOR CEILINGS Elat Flat Rough Texture USG Alkyd Primer Sealer TEXOLITE Primer-Sealer None (smooth where required) USG Alkyd Primer-Sealer None, or TEXOLITE Primer-Sealer None (smooth where requited) PRO KYD Alkyd Flat NR/ms Any USG lalex paint shown loi ini. walls IMPERIAL QT Texture Finish W Bl. Rl. St - S only l 24 24 - not fee. 400 - NOUS: "Dfyinf Fmr "Covtui*" ttwiilti it* btd 60 <(* conditions. Touch - lufitiluio can ba lalufnad lo tivini arcat. Abbiavulmu, llathod of Apotkatlon: - brush, I rollai. S - spfiv. I > trowol; I, 2. | - oidor of piafoianca. AbbiamUona, Tbiooau: MH/a--Nolrocommtndtf. oi aalai spaiingljr; NM/ina-- Noliacointnandad, uianmiaial ipuiinl naadcd, SS/USC--Special Solvent manulacluf ad by U S.Cyptum. ozco Etoaa CHAPTER 4 CB Systems and oa Performance Data o M >4 chapter 4 page Partition, Wail and Ceiling Systems Metal Stud Partitions Metal Stud-lMPERiAL Partition Chase Wall Partitions Metal Stud-ROCKIATH Partition TRUSSTEEL Stud-ROCKLATH Partition TRUSSTEEL Stud-Metal Lath Partition Solid Plaster Partitions IMPERIAL-Solid Partitions Solid Long Length Rocklath Partition Solid Metal Lath Partitions Masonry Partitions Pyrobar Tile-Plaster Partition PyROBAR Tile-ROCKLATH Partition Pyrobar Tile-Metal Lath Partition Wood Frame Partitions & Ceilings --Imperial Partition & Ceiling --Rocklath Partitions & Ceilings --Metal Lath Partition & Ceiling Radiant Heat Ceilings Metal Framed Ceilings Metal Furring Channel-Gypsum Lath Ceilings Brace-Tite Ceiling System Metal Lath Furred. Suspended Ceilings Exterior Wail Furring Systems Metal Channel Furring Systems --Imperial System --Long Length Rocklath System --Channel Stud-Metal Lath System Wood Furrmg-RoCKLATH System TRUSSTEEL Stud Furring Systems Metal Stud Furring System Exterior Plaster System Structural Fireproofing Metal Lath Fireproofing Caged Beam Installation Pyrobar Tile Fireproofing Gypsum Lath Fireprooting Fire and Sound Tests 109 110 112 114 115 120 126 129 129 132 134 138 138 141 143 144 1 z l CHAPTER 4 Systems and Performance Data PARTITION, WALL AND CEILING SYSTEMS United States Gypsum has developed a complete line of parti tion, wall furring and ceiling systems. A system consists of necessary components that, when erected, wilt offer the func tions desired to provide attractive appearance and meet building requirements. Each of these systems has been engineered to provide differ ent characteristics of structural stability, fire rating, sound transmission loss or other factors. Maximum crack resistance is built in; insulation value and vapor barriers also are in cluded in some combinations. All systems are planned to offer constructions that are lightweight, space saving and easy to install. This section describes the types of systems, their advantages and methods of construction. See Chapter 3 for complete information on products mentioned. METAL STUD PARTITIONS These partitions are strong, lightweight, non-load bearing assemblies consisting of wire web-type TRUSSTEEL Studs or channel-type USG Metal Studs anchored to door and ceiling runners. This framing is covered with Imperial Plaster Base (one or two layers), Rocklath Plaster Base or metal lath-- depending on particular needs--and plastered as specified. See Chapter 3 for complete description of materials and ac cessories used in these systems. Metal stud partitions are ideal space-saving dividers within units, economical corridor partitions and, in certain cases, highly sound-resistant party walls (see details under specific headings). Among their advantages are the following: ECONOMY: low material cost, speed of installation and versa tility of the system provide construction cost comparable to that of any partition of same thickness. od LIGHTWEIGHT: the completed systems weigh appreciably less (B than masonry partitions of the same thickness. O TIRE RESISTANCE: up to 2 hr. ftre-resistance rating. U SOUND RESISTANCE: STC as high as 52; suitable for party Q wall with some combinations. M STRENGTH: resists racking; withstands normal impact loads. (J 110 SYSTEMS: Metal Stud-1 mperial Partition Metal Stud-IMPERIAL Base Partition (Single Layer) This system consists of lightweight steel channel studs set into floor and ceiling runners. Sound attenuation blankets are placed between studs if specified and each side of the framing is faced with or Imperial Plaster Base. Either Imperial Plaster Finish is applied in a single-coat system, or Imperial Plaster Basecoat is used in two-coat application as a base for Diamond Finish, Strccto-Gauce Gauging Plaster and lime, or Keenes-lime-sand float finish. This construction is ideal for interior partitions in office and industrial buildings, high-rise apartments, hotels, motels and similar construction. There are three stud and runner widths: IS"; 2H" and 3S" with allowable partition heights of 8'-6"; ll'-O" and 14'-6" respectively. Chase wall height limit is lO'-O". Installation First step is to align metal floor and ceiling runners. To improve sound control characteristics, apply a non-hardening caulking material as specified for ceiling or partition perime ters. Fasten runners with H" concrete stub nails or powerdriven anchors spaced not over 24" o.c. Secure to suspended ceilings by wire ties or other positive fastening not more than 16" o.c. Position studs not over 16" o.c. to engage with floor and ceiling runners. Place studs in direct contact with ail door frame jambs, abut ting partitions, partition corners and existing construction elements. Fasten these studs to floor and ceiling runners using positive screw attachment or a USG Metal Lock Fas- ..J Metal Stud-1 mperial Partition: SYSTEMS 111 tener (see Chapter 5). Grouting of door frames is always recommended and is required where heavy or oversize doors are used (see Chapter 5 for grouting information). When necessary, splice studs with at least S' nested lap secured with 2 screws through each flange or by wire ties 1" from i each stud end. I I Where stud is to directly abut exterior wall and there is a possibility of condensation or water penetration through the wall, place an asphalt strip between stud and wall surface. Over metal doors and borrowed light frames, place a section or runner track horizontally with a web-flange bent at each end. Fasten with one positive attachment per flange. At the location of vertical joints over the door frame header, posi tion a cut-to-length stud extending to che ceiling runner. Apply single layer Imperial Plaster Base, face out, with long dimension at right angles to framing members. Ends and edges must abut over stud flanges. Use base of maximum practical length to reduce number of end joints and arrange joints on opposite sides of partition so that they occur at different studs. For horizontal application of base, space USG 1" Type S Screws max. of 12' o.c. in field of base and 12" o.c. staggered along abutting end join^. In optional vertical ap plication of the plaster base, space screws max. of 12' o.c. in the field of the plaster base and 8~ o.c. staggered along ver tical abutting edges. i 112 SYSTEMS: Metal Stud-1 M PE rial Partition Metal Stud--IMPERIAL Base Partition (Double Layer) This partition has a 2 hr. fire rating with Imperial Plaster Base Type X and a sound rating up to 52 STC. These features, in addition to its high strength and abrasion resist ance, make it especially suitable for use in schools, hospitals and for party walls in dormitories or apartment buildings. Installation Apply tt" or H" Imperial Plaster Base to metal stud framing in vertical position. Attach inner piaster base layer with USG l" Type S Screws spaced 24" o.c. and the outer layer of plaster base, with joints offset with USG l5*" Type S Screws, 12" o.c. For maximum STC rating runner tracks and end studs must be caulked each side as weil as perimeter of second layer of plaster base. Also, 1" Thermapiber Sound Attenuation Blanket should be stapled to back of plaster base, one side, leaving no voids. Apply Imperial Joint Rein forcing Tape the full length of joints, following procedures in Chapter 2. wall plan sections caulk-y j-- double layer (lammateo) IMPERIAL plaster base i I caulk r 1/2" min. 1 USG control joint * 093 control joint comer Wi D; O- U~- f 114 SYSTEMS: Metal Stud-1 imperial Partition Plaster Application Apply Imperial Plaster Finish to a min. of 1/16" and max. 3/32" finished thickness. Embed tape and fill beads with a tight, thin coat and allow to set. Then scratch in a tight, thin coat and double back to the full thickness, filling the voids and imperfections. When surface is firm, finish troweling using water sparingly. FOR TWO-COAT APPLICATION, use Imperial Plaster Basecoat and complete plastering as outlined in Chapter 2. Metal Stud-ROCKLATH Partition: SYSTEMS 115 The metal stud chase wall may be formed of two USG Studs bracketed together with 12" deep gussets of H" or 44" Imperial Plaster Base. Gussets should be spaced not to ex ceed 36' o.c. and securely attached to studs using three USG 1" Type S Screws. Limiting height for this chase wall is 10'. Installation Align wall partitions accurately using a double row of floor and ceiling runners spaced to accommodate service installa tions. Attach runners 24" o.c. to concrete slabs with concrete stub nails or power-driven anchors and to suspended ceilings with toggle bolts or staples. Position a double row of USG No. 138 Metal Studs opposite each other in pairs with flanges pointing in the same direc tion, and spaced no greater than 24" o.c. Anchor ail studs to runner flanges with USG 44" Type S-12 Pan Head Screws. For studs located at partition intersections and corners, anchor to runner flanges with Metal Lock Fastener or posi tive screw engagement through each stud and runner flange. Cross-brace between rows of studs with pieces of Vi" or -V Imperial Plaster Base 12" deep and a width to flt between studs. Fasten to stud webs at quarter points in partition height with USG 1" Type S Screws spaced 8" o.c. m each stud web or a minimum of three screws per stud web. Apply single face layer or base layer of '.4" or 44" Imperial Plaster Base in vertical position. Plaster as outlined for Single and Double Layer Metal Stud Systems, using beads, trim, and other required accessories. Metal Stud--ROCKLATH Plaster Base Partition i I 116 SYSTEMS: Metal Stud-ROCKLATH Partition with USG MS-1 Clips or USG Brand 1" Type S Screws. Either clip or screw attached, this system is an easily in stalled, incombustible, non-load bearing partition. It is espe cially suited for application where a strong plaster finish is required but speed and economy are also major factors. The clip-attached combination forms a resilient base for the economical application of gypsum piaster and in some areas is the lowest-cost plaster system oifering a 49 STC. The screw-attached combination offers strength and rigidity, and is especially suitable where adequate sound control plus the durability of plaster is important. Installation 1 For framing, except spacing, follow specific directions in sec| tion on Metal Stud-Imperial Plaster Base for layout, caulk< ing and assembly of metal stud framing. For clip attachment | or screw attachment space studs IS" o.c. Place a stud 2" from abutting partitions, partition corners, partition termi nals and door or borrowed light openings. Position Rocklath Plaster Base, face out, with the long di mension ac right angles to the framing members. Stagger end joints in successive courses and have joints fall between I studs. Make sure that the Rocklath is cut accurately to fit over electrical outlets and other openings. FOR CUP ATTACHMENT, fasten Rocklath with USG MS-1 Clips to studs spaced 16" o.c. and secure corners of lath with Bridjoint B-l Clips. FOR SCREW ATTACHMENT, fasten ROCKLATH Plaster Base to studs spaced 16" o.c. with USG 1' Type S Screws spaced 2" from edges of Rocklath. Use an electric screw gun. Secure comers between studs with Bridvoimt B-l Clips. Apply gypsum plaster in the 2-coat method to *4' grounds. Stud spacing may be 24" o.c. but requires 3-coat plaster ap plication for this wider stud spacing. See Chapter 3 for plas tering directions and descriptions of trim accessories. USG METAL STUD-PARTITION TECHNICAL DATA Stud Width IM' 2W 3V 1' 13) Section Modulus .G49'1 .086'' 142M .156'* Partition Thickness 3 V.' w- 5H- sy,- Maximum Height fl> (2) 3' 12- 16' I7'-3" (I) kddtrcu cviliiif otijfit oy >PKt. (]) Wnl Coast only. ,| lt|mwi|nt i(|r|iia baieceat i* used. (2) For 2<* stud Metal Stud-ROCKLATH Partition: SYSTEMS 117 BRIDJOINT B-l Clip ROCKLATH edge joint Screw application ROCKLATH plaster base clip attached -- 7/8" -use screw type S screw attached 118 SYSTEMS: Metal Stud-ROCKlATH Partition ceiling attachment ceiling attachment finished ceiling unfinished 8B0I3 0282 floor attachment & base ) ( (.. \p L> top set caulk / ) USG 2-1/2" metal / base USG splice plate metal TRUSSTEEL stud Partitions: SYSTEMS 119 The Trussteel Stud Partition System is a strong, light weight, non-load bearing assembly. Adaptable to virtually all types of construction, it is economical and easily erected. The system is often selected for school, hospital, apartment and office construction because of its high fire-resistance, excel lent sound transmission loss ratings, and space for piping and wiring. The open web of the truss design provides maximum free space for horizontal, vertical or diagonal placement of pipes or conduit. Web members can be cut to accommodate larger ducts and pipes without seriously impairing the strength of the partition. Trussteel Studs provide a strong frame for resilient or di rect attachment of H" RocxlaTH Plaster Base (plain or perforated) or USG Metal Lath. The studs come in 5 widths to provide wall thicknesses to meet almost every job require ment. Some of the advantages of this system are: VERSATILITY: studs are 1**, 2%', 3*', 4' and 6' to provide a variety of partition widths. LIGHTWEIGHT: partition assembly weighs about 11 lbs. per sq. y ft. plastered with perlite aggregate plaster; 14 lbs. per sq. ft. with sand aggregate plaster. ** (J FIRE RESISTANCE: uses incombustible materials in various combinations to qualify for 1 and 2-hr. fire ratings. g SOUNO RESISTANCE: as high as 52 STC possible; variations of 2 materials allow ratings over 40 STC. 120 SYSTEMS: Trussteel-ROCKlath Partition TRUSSTEEL Stud-ROCKLATH Base Partition RESILIENT ATTACHMENT of Vi" perforated Rocklath Plas ter Base to 1V4" Trussteel Stud framing reduces plaster cracking due to structural movement and with Vi" gypsumsand plaster provides a 1 hr. fire rating. With 314" studs, Vi" Rocklath Plaster Base and Vi " gypsum-sand plaster, the STC is 52. DIRECT ATTACHMENT of Vi " Rocklath Plaster Base to TRUSSTEEL Stud framing produces a strong, lightweight par tition assembly. With 2 H " TRUSSTEEL Stud framing, Vb' per forated Rocklath and Vi' gypsum-perlite plaster, the fire rating is 2 hrs. With lVi" TRUSSTEEL Studs, perforated Rocklath and li" gypsum-sand plaster, the fire rating is 1 hr. and STC is 41. Installation Align USG Snap-In or Regular Runner Track and anchor to concrete slab using concrete stub nails or power-dnven anchors spaced not over 21" o.c. For anchoring to ceiling grillage, tie runners with a double '* strand of 18-ga. tie-wire spaced not more than 16" o.c.: to t plaster or gypsum lath use toggle bolts or staples spaced not 2?;. more than 24" o.c. For best sound control, caulk perimeter of Rocklath and plaster at floor line. Install Thermafiber f Sound Attenuation Blanket to back of lath one side where Mi'-* indicated for desired rating. In all fire-rated partitions, TRUSSTEEL Stud must be attached to the regular or snap-in runner track with Trussteel Stud TRUSSTEEL-ROCKLATH Partition: SYSTEMS 121 Shoes at the ceiling. Snap-in runner track with studs cut accu rately to lengths may be used for floor and ceiling attachment where the construction is non-fire-rated. This track may be used at the floor in fire-rated partitions. With USG Regular Runner Track and Stud Shoes, the studs must be no more than 3" from ceiling; with USG Snap-In Runner Track, no more than from ceiling. Place studs vertically, 16* o.c., and snap into runner tracks at floor and at ceiling secure with a pair of shoes crimped or wire-tied in place, using a double strand of 18-ga. tie wire. Locate a stud 2" from abutting partitions, partition corners, partition ter minals and door or borrowed light openings. FOR RESILIENT ATTACHMENT, start at the bottom with the long dimension of the Rocklath Plaster Base at right angle to studs. Butt ends of Rocklath together and clip in place using Resilient Starter-Finisher Clip R-SF and Resili ent Field Clip TR-1, spaced not to exceed 16" o.c. Stagger end joints between studs and align corners of lath with Briojoint B-l Field Clips. FOR DIRECT ATTACHMENT of Rocklath Plaster Base, follow procedure for resilient attachment but use Trus-Lok Starter Clips TL-2 for first course and Trus-Lok Field Clips TL-1, spaced not to exceed 16" o.c., for succeeding courses. Fasten the finishing course of Rocklath with 1" No. 12 flat head self tapping sheet metal screws, driven between vertical stud wires and spaces 8' from ceiling. Stagger ends of lath between studs and secure corners with Bridjoint B-l Field Clips. Plaster Application Apply gypsum-sand or gypsum-perlite plaster to H' grounds in two or three-coat application. See Chapter 3 for. specific plastering directions. ^ A ,..rr TRUSSTEEL STUD-PARTITION TECHNICAL OATA Stud Width IV 2V 3V 4' 6* Section Modulus oar5 .1056'* .1420'* .1825'* .277'* Thickness Direct Att. 3v 5V 6' 8' Thickness Resil. Att. V 4V 5%' 6V 8V Maximuni Height Studs 16' o.c. S' 15' 21' 22' 26' i 122 SYSTEMS: TruSSTEEL-ROCklath Partition resilient attachment ceiling attachment 98S0 E ioaa Trussteel-ROCKLath Partition: SYSTEMS 123 I ' &%*** 124 SYSTEMS: TrussteEL-ROCKLATH Partition direct attachment ceiling attachment ~T cross section transverse to furring channel floor attachment & base cross section parallel to furring channel I 126 SYSTEMS. TruSSTEEL-Metal Latn Partition TRUSSTEEL Stud-Metal Lath Partition This partition system is readily adaptable to curved wails and special constructions as well as to conventional reciuirements. The mechanical keying and uniform reinforcing pro vided by the metal lath contribute to excellent over-aii per formance. The truss design of the studs allows a maximum of free space for encasing pipes, conduits or ducts horizontally, vertically or diagonally; studs may be cut and spliced easily without impairing the structural integrity of the assembly. The studs are attached to door and ceiling by ciios or runner tracks and stud shoes. Lath is either directly wire-tied to the stud or resilientlv attached by means of USG Resilient Ciios and N" pencil rods. The assembly qualifies for 2 hr. fire rating (with wood fiber piaster sanded 100:1) ana STC values as high as 50 with resilient attacnment. Non-load bearing; stua spacing and limiting neignts vary with type of metal lath and width of stud. Also used for furring and core wall construction. Installation ; FOR OIRECT ATTACHMENT of metal lath, folic ,-eneral directions on TruSSTEEL Stud framing assembly n section on Trussteel Stud-RocKLATH System. Erect Trussteel Stud framing in accord with type of lath and limiting heights indicated in the table following. j ,, f . TIE DIAMOND MESH LATH to stud flanges with 18-ga. tie wire - at 6" intervals along each stud flange. ES'T QJ ~ APPLY RI8LATH with nb projections against supports, and Oss wire-tie to supports 6" o.c. Nest side and end ribs of lath ana **" wire-tie between supports not to exceed 9" intervals. Stagger ends on all types of lath sheets so that lath on opposite sides ^3 and sheets below on the same side do not end on the same stud. Lace end laps or wire tie at 9" intervals. *0* 1 Trussteel*Metal Lath Partition: SYSTEMS 127 Plaster to *1" grounds using gypsum-sand 100:2, 100:3 mix in 3 coats. See Chapter 3 for plastering details. direct attachment corner floor attachment & base metal lath i^ gypsum plaster j. 1 partition intersection 1 6 2 0 ElO BB FOR RESILIENT CLIP ATTACHMENT, follow general pro cedures as for direct attachment, spacing studs not more than 16* o.c. Next, snap USG No. 400 Resilient Clips over the chords of studs, with clips located not more than 4' from floor and ceiling. Clip V*' pencil rods of ceiling height into small loops of resilient clips. Position USG 3.4 lb. Diamond Mesh Metal Lath with long dimension of sheets across supports with ends of lath lapped at least 1*. See Metal Lath section in Chapter 1 for general application direction. Using 18-ga. 128 SYSTEMS: TruSSTEEL* Metal Lath Partition wire, tie lath to pencil rods and all supports at intervals not exceeding 6". Plaster Application Plaster to ground thickness depending upon type of lath and stud spacing used (see table). Apply plaster in the three-coat method as described in Chapter 3. resilient attachment ceiling attachment finished ceiling rough ceiling caulk no. 60 casing bead floor attachment & base TRUSSTEEL stua snoe 1/4" pencil rod snap-m j runner track 'i l \ -caulk top set top set TRUSSTEEL STUD-PARTITION TECHNICAL DATA Stud Partition Thickness Maximum Partition Heights Width 1H' 2H' 3y' 4' 6' Section Modulus .66J5'> .1056'* .1420'* .1825'* .277'* Oia. Mesh or K" Z-Riblath Resilient Oia. Mesh 3VT 4*' 4r 5' <y.' sy.' 5H' Hi' m- 8W' H' Riblath 3H' 4H' 5W S' 8' Ola. Vf y.' Mesh Riblath Riblath Studs Studs Studs 16' o.e. ir o.c. 24" o.e. 9' -- -- 15' 14' 9' 21' 18' 13' 22' 20' 16' 26' 24' 20' Not*: Oitmond ida im H* Z-RibURi mow* it baud an 3.4-lb. par sqm** yard of lam. IMPERIAL-Solid Partition: SYSTEMS 129 SOLIO PLASTER PARTITIONS These Solid Plaster Partition Systems are economical and space-saving while offering good strength, excellent fire re sistance and acceptable sound isolation on area dividers. The monolithic plaster construction results in an extremely du rable and easily decorated surface making any of these sys tems nationally accepted for use where strong, non-load bear ing partitions are specified. The wide use of these systems in schools, dormitories, apartments and hotels shows that their many advantages are recognized by leading architects and builders. They are best used where few openings are required and special fitting or cutting is minimum. There are five combinations of gypsum lath-plaster or metal lath-plaster solid partitions: 1. Imperial Base-Solid 2. Imperial Base-Double Solid 3. Solid Long Length Rocklath 4. Solid Studless Metal Lath 5. Solid Channel Stud Metal Lath IMPERIAL Base-Solid Partition Consisting of Y;' Imperial Plaster Base laminated to both sides of 1' USG Coreboard secured to floor and ceiling runners, this partition is finished with high-strength Imperial Veneer Plaster that provides a beautiful, hard fin ish. Height limit is 10 ft.--thickness 2 *4 Advantages of the system are: FIRE RESISTANCE: estimated fire rating of 2 hrs. PERFORMANCE: ideal for areas requiring high strength and crack resistant features. VERSATILITY: adaptable to most dimensions or modules-- meets most normal design and job conditions. BB013 0293 130 SYSTEMS: IMPERIAL-Solid Partition ECONOMY: partitions go up fast. Finish can be rapidly ap plied by hand or machine. Installation Snap chalk lines on floor and ceiling to mark partition loca tions. Fasten 7i" x 1%' metal angle runner in place using concrete stub nails or power-driven fasteners spaced not over 24" o.c. Set all metal door frames before application of 1" coreboard and install borrowed light frames as coreboard erection proceeds. Cut USG Coreboard to fit between floor and ceiling runners. Where conduit and outlet boxes occur, cut necessary open ings. Install coreboard vertically with tongue edge leading and fasten with USG 1H" Type S Screws. Use two screws at top and two screws at bottom 2" from edges, to fasten core board to runners. At partition intersections or corners, use lOd nails to fasten coreboard. Nail along guiding center line, 24" o.c. After the coreboard has been installed, spot-grout the door frames where each jamb anchor clip is located (see Chapter 5 for details). Cut the Imperial Plaster Base to the full floor to ceiling dimen sion and strip-laminate (see page 49) to coreboard, arranging panels so that vertical abutting joints are at least 3" away from coreboard joints.. For good adhesion use USG Type G Screws, spaced 2' from end and 4' o.c. m field of panel; 1' from ends and 3' o.c. along vertical edges and 2" from vertical edges. Drive with electric screw gun. When adhesive has dried--about 48 hrs.--tape all joints and apply 1/16" to 3/32' Imperial Veneer Plaster following directions in Chapter 2. ceiling attachment rough or finished ceiling 7/8"xl 3/8" 22-ga. metal angle at ceiling i ;i ij 1 set \, /7 f b metal USG metal base USG metal base splice plate attached by bolt thru partition Bf o'! -P W V '.e r <-v T IMPERIAL-Oouble Solid Partition: SYSTEMS 131 IMPERIAL Base-Oouble Solid Partition Floor and ceiling runners for this double solid partition must be spaced not less than ll4" apart to provide 46 STC rating, and 3' apart for outstanding sound isolation of 55 STC. Thermafiber Sound Attenuation Blankets are stapled to the back of coreboard on one side of the latter assembly. It also serves as a chase wall. For runner attachment and coreboard erection, follow directions outlined for IMPERIAL Base-Solid Partition. Laminate face layer of IMPERIAL Plaster Base to coreboard as described in Chapter 2. Follow taping and plastering di rections in Chapter 2 for applying Imperial Veneer Plaster. ceiling attachment rough or finished ceiling floor attachment t base i a u o w 41 u . I * 132 SYSTEMS: Long Length Rocklath Partition Solid Long Length ROCKLATH Partition y irtf -.1 This partition assembly is an economical monolithic plaster construction, 2" to 2hi" in thickness, which has been readily accepted for its space-saving features. H", V-edge, Long Length Rocxlath Plaster Base is held vertically by floor and ceiling runners and plastered on both sides. Temporary bracing is required until the assembly has been partially plastered. Limiting height is 10'. This assembly is ideal for use wherever non-load bearing plastered partitions are desired and particularly where space saving and economy are the most important factors. Its fea tures are: ECONOMY: saves time and money. Quickly estimated and easily erected. No waste, even on small jobs. PERFORMANCE: used on many jobs with excellent results-- few problems. LIGHTWEIGHT: in structural design the dead load for 2" solid plaster partitions ranges from 11 to 16 lbs. per sq. ft., de pending on the type of plaster aggregate used. FIRE PROTECTION: constructed of incombustible components, this assembly has an established Are-resistance rating of 1 hr. STRENGTH: a 240 ft.-lb. impact load concentrated at the cen ter of a 2'x8'-0'xl6'-0' panel failed to cause serious cracking. Additional strength and rigidity may be gained by increasing the plaster thickness. Installation Snap chalk lines to mark partition locations. For floor tracks use USG Metal Base and Double Base Clips or USG Floor Runner and Screed attached with stub nails or power-dnven anchors at 24' o.c. Attach USG L-Type Ceiling Runner to grillage with double strand 18-ga. wire and to plaster or gypsum lath with toggle bolts or staples at 16" o.c. Cut Vt" Long Length Rocklath Plaster Base to size allowing Long Length Rocklath Partition: SYSTEMS 133 Yt" min. and IV1' max. clearance at ceiling. Erect vertically with the V-joint edges brought into close contact with the adjacent edge. Attach Rocklath to the floor runner or set in a groove of the grouted metal base and securely clip to the ceiling runner with two USG Ceiling Runner Clips per board. Wire-tie the Rocklath securely to the jamb inserts or door frames. Lath with cut vertical edges should be used only at the ends of partitions or at door frames and not in the central portion of the partition. Grout door and borrowed tight frames as described in Chapter 5. Temporary bracing should be not less than \" c.r. channels placed horizontally and 1V4" angle stiffener placed vertically. For partition up to 8'-6" height, place one horizontal brace near mid-height of the partition. For partitions over 8'-6" height, use two horizontal braces at third points. Use vertical stiffeners placed not over 6' o.c. on partitions over 6' in length. The horizontal channel should extend the full length of the partition and be fastened with USG Bracing Clip or securely wire-tied at the center of the lath and the ends of the channel. Wedge the vertical stiffeners at top and bottom and securely wire-tie to horizontal bracing. Keep bracing in place until the brown coat of plaster on the side opposite the bracing has set. Set grounds to provide *4" min. plaster thickness, including 1/16' finish coat. Plaster Application Plaster to grounds with 100:2-100:3 gypsum-sand plaster (for 1 hr. fire rating use 100:1-100:2 gypsum-sand plaster or gypsum-perlite at 100:2-100:3). Apply scratch coat %" thick--with max. set of 3 hrs.--to each side of the lath, both sides to be scratch coated within a 3-hr. interval. Cross-rake lightly in horizontal direction only. Apply brown coat to the unbraced side after scratch coat has set and partially dried (not less than 16 hrs.). After brown coat has set firmly (not less than 3 hrs.), carefully remove braces and brown coat the second side. Bring out brown coat to a true plane and leave rough. Apply finish coat plastering as described in Chapter 3. BB013 0297 ceiling attachment floor attachment 134 SYSTEMS: Studless Metal Lath Partition Solid Studless Metal Lath Partition This partition assembly is an economical monolithic piaster construction, 2", 214", or 2H" in thickness, widely recognized for its space-saving and crack-resistance features. USG H' Riblath, attached at floor and ceiling by special runner, con tributes vertical rigidity and reinforcement while providing an excellent lightweight plaster base. Nesting and wire-tying of ribs on adjacent sheets makes the riblath a nearly continu ous reinforcing membrane which requires temporary bracing only until the partition has been plastered on one side. This is a non-load bearing partition with a limiting height of 10`. This assembly is ideal for use wherever space saving and economy are the most important factors. Its features are: ECONOMY: saves time--money. Easy to estimate; goes up fast. PERFORMANCE: used in hotels and public buildings with ex cellent results--few application problems. FIRE PROTECTION: constructed of incombustible components, this assembly has a 1 hr. fire-resistance rating. STRENGTH: resists high impact loads without discernible cracking. Additional strength and rigidity may be gained by increasing the plaster thickness. Installation Install track to chalk lines snapped on floor and ceiling. The floor tracks are USG 214" Metal Base and Double Base Clips or USG Floor Runner and Screed securely attached 24" o.c. For ceiling runners use USG L-Type Ceiling Runner at tached 16" o.c. and located so that the USG H' Riblath will be positioned in the center of the partition. Attach to concrete with concrete stub nails or power driven anchors: to ceiling grillage with a double strand of 18-ga. tie wire; to piaster or gypsum lath with toggle bolts or staples. Erect nblath vertically, attach to the floor runner or set in a (jj groove of the grouted metal base and securely wire-tie 8" o.c. B B 0i3 C Studless Metal Lath Partition: SYSTEMS 135 to the ceiling runner. Wire-tie the nested edges of sheets 12' o.c. and tie the nbiath to jamb inserts or door frames. At all interior angles, form metal lath into the corners, carry out onto the abutting surface and adequately secure. Finish partition terminals and eased openings with USG Partition Terminal, wire-tied securely in place. Temporary bracing shall not be less than %' c.r. channels placed horizontally near mid-height of the partition, tied to the riblath 24' o.c. and braced with lii' angles placed verti cally, not over 6' o.c. Wedge vertical braces at top and bottom and tie the horizontal ' channel to hold lath in place. Plaster Application First apply scratch coat to side opposite bracing, allow to set and partially dry. Next apply brown coat to full grounds on side opposite the bracing. Be sure plaster is completely set before removing bracing; then apply brown coat to full grounds on side previously braced. Apply conventional finish coats to both sides of partition. For normal application use 100:2 scratch coat and 100:3 brown coat. For 1 hr. fire rating I 136 SYSTEMS: Channel Stud-Metal Lath Partition Solid Channel Stud-Metal Lath Partition 7 Economical in construction, this partition has the advantage of higher fire ratings--2 hrs. with 3.4 lb. diamond mesh lath and perlited plaster. USG Cold Rolled Channels serve as permanent studs, 16" o.c., attached to floor and ceiling by special runners with the metal lath wire-tied to studs. Metal lath for this assembly is available in two types: 2.5 lb. or 3.4 lb. diamond mesh lath; 2.75 lb. or 3.4 lb. Z-nblath. The excellent mechanical keying properties and equal distribution of reinforcing provided by this plaster base give these assem blies high Are resistance and acceptable sound transmission loss ratings. For greater fire resistance or increased ceiling height, solid partitions thicker than 2' may be used. Features: ECONOMY: easy to estimate and goes up fast. For small jobs, materials are readily available in dealer stocks. PERFORMANCE: widely used in schools, dormitories, apart ments and hotels with excellent results. LIGHTWEIGHT: 12 to 23 lbs. per sq. ft. depending on type of plaster aggregate and plaster thickness used. FIRE PROTECTION: constructed of incombustible components, this assembly has established Are ratings of up to 2 hrs. SOUNO ISOLATION: sound transmission loss considered satisfactory for normal requirements within offices, apartments and hotel units. STRENGTH: highly resistant to impact damage. Additional strength and rigidity gained by increasing plaster thickness. .; : ' Installation Snap partition lines on floor and ceiling. Fasten Z-type run ner to ceiling. Attach double base clips--spaced 16* o.c.--to structural floor with concrete stub nails or power-dnven fasteners.