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FOREWORD Because of the vastly increased use of gypsum drywall products, there is a great need for mechanics skilled in its application and a need for organized instructional material to help upgrade job quality. Por drywall contractors who install gypsum wallhoard. for builders, architects and students of architecture, this handbook of Siiuutuock Wallhoard construction will be invaluable. It provides information that represents many years of practical manufacturing and on-the-job experience by the United States Gypsum Company. . The following trade marks are owned by the United States Gypsum | Company and used by it to distinguish products only of its manufac ture. AH but those indicated by an asterisk are Reg. U S. Pat. Off. Sheetrock Wallhoard, Sealer Perf-a-tape Joint System PerF-a-bead Corner Reinforcement Texolite Paint Duraval Paint Textone Plastic Paint *Firecode Wallhoard Baxbord Gypsum Backing Board Dur-a-bead Metal Corner Reinforcement Perf-a-trim Gypsum Wallboard Trim, USG Metal Trim, Gypsum'Wallhoard Trim, Texture Paints Trussteel Studs Trus-lok Clips Briojoint Clips BB026 1890 CHAPTERS 1. BOARD APPLICATION AND FINISHING 2. FIELD PROBLEMS 3. METAL PRODUCTS ACCESSORIES 4. SYSTEMS 5. MISCELLANEOUS APPLICATION METHODS 6. TECHNICAL DATA 7. TOOLS 8. PRODUCT INFORMATION PAGE 5 31 41 47 79 91 103 115 W0 52 Copyright 1958 -- United States Gypsum Company -- August 1958 mm UNITED STATES GYPSUM The Greatest Name in Building BB026 1891 Gypsum wallboard is composed of a gypsum core encased in a lough, finish paper on the face side and a strong liner paper on the back side. Gypsum wallboard represents decades of laboratory research and on-the-job testing. The nation's foremost home builders prefer fireproof Sheetrock Wallboard over all other drywall systems when it comes to truly fine interiors. Through long experience they know that pre-formed Sheetrock panels will meet their own high standards for walls and ceilings every time--and will provide the quality features expected by discriminating home buyers. In re sponse to today's building needs for economy and speed of erection without sacrifice of quality or durability, Sheetrock Wallboard is installed in millions of fine residential and commercial buildings everywhere. Br'Tlnii' ii WSJ Board Application and Finishing CONTENTS FRAMING REQUIREMENTS.................................................................. ADVANTAGES OF GYPSUM DRYWALL CONSTRUCTION........................ PUNNING THE JOB............................................................................. ESTIMATING--LENGTHS AND FOOTAGE NEEDED.............................. SELECTING THE MATERIAL................................................................. PRINCIPLES OF SHEETROCK ERECTION.............................................. SINGLE UYER SYSTEM....................................................................... ADHESIVE NAIL-ON SHEETROCK WALLBOARD CONSTRUCTION.......... THE DOUBLE NAILING SYSTEM........................................................... RESURFACING OLD WALLS AND CEILING SURFACES.......................... ELECTRICAL CUT OUT OPENINGS......................................................... APPLICATION OF PREDECORATED SHEETROCK.................................. ARCHES................................................................................................ REPAIRING DAMAGED SHEETROCK WALLBOARD............................... NAILS AND NAILING............................................................................. NAIL SPECIFICATIONS...................................................... IMPROPER APPLICATION PROCEDURES............................................. TREATING JOINTS AND CORNERS WITH PERF-A-TAPE JOINT SYSTEM ALL PURPOSE RUDY MIXED PERF-A-TAPE CEMENT . ALL PURPOSE RUDY MIXED PERF-A-TAPE CEMENT--PROFESSIONAL APPLICATOR USE ONLY............................................................... HOW TO REPAIR PUSTER CRACKS WITH PERF-A-TAPE JOINT SYSTEM PAGE 6 7 8 9 10 11 12 14 17 18 18 19 19 19 20 20 23 25 29 30 30 FRAMING REQUIREMENTS The framework is the backbone of any building. Good framing is essential regardless of the type of wall surfacing material used. The framework, studs, joists, rafters and plates to which SnnnntocK Wallboard is applied perform the triple function of supporting the structure, transferring loads to the foundation and also provide a base for wall and ceiling finishes. The Essentials of Good Framing arc: 1. Framework should meet minimum requirements of F.H.A., V.A. and/or local building code regulations. 2. Framing and bridging members shotdd be adequate to c.arry the design or code loading. 3. Lumber should be of a good grade with a moisture content as low as practical or economically sound. U.S. Department of Agriculture pub lication, Wood Handbook No. 72, recommends 7% to 12% for dry southern states and 9% to 14% for the remainder of the United States. 4. Framing lumber should be straight, true, and of uniform dimension. 5. Studs, plates, joists and headers should be checked for accurate spacing and alignment. Spacing of framing should not exceed maximum allow able for the thickness of Sheetrock to be used. 6. Horizontal load bearing members should be of sufficient dimension, and trusses should be fabricated in such a manner that when the full design load is applied the deflection should not exceed 1/360 of its span. 7. Provide studs at corners for end or edge nailing of Sheetrock. 8. All joists must be level and correctly bridged in spans over 6'. Bridging should be securely nailed and should not extend below the bottom of the joists. 9; Electrical outlets, switch boxes, all concealed heating ducts and rough plumbing work should be set to receive the thickness of the Sheetrock Wallboard to be used on the job so that none will cause the board to be held away from the framing. Rough plumbing work and heating ducts , should be tested before Sheetrock application. 10.1 Window openings should be properly framed with double studs and headers. 11. Provide members for nailing at both sides of Sheetrock interior vertical angles. 12. Top plate shall be of sufficient dimension to transfer load from joists and rafters in a load bearing wall. Single plate may be used in non-load bearing partition. 13. Provide adequate headers to support fixtures such as sinks, cabinets, towel rods, soap dishes, etc. 14. Exterior door frames, window frames and sash should be set for the thickness of wallboard to be used. 15. ` After the house is enclosed, allow it to stand as long as possible prior to the application of the gypsum wallboard. Healing in winter or during . damp conditions is recommended. Provide a uniform temperature in a , range of 5()r to 70 F. Ventilation must be provided to eliminate excess I moisture. BQ026 1892 ADVANTAGES OF GYPSUM DRYWALL CONSTRUCTION FIREPROOF Gypsum will not support combustion. Gypsum when exposed to fire be haves like a cake of ice when the flame from a blow torch is applied to its surface. The ice melts on the surface in contact with the flame while the opposite side remains cool. Similarly, the surface of gypsum wallboard opposite the flame remains at a relatively low temperature until the gypsum core is completely decomposed. SMOOTH UNBROKEN SURFACES Perf-a-tape Joint System provides a means for concealing the joints between Sheetrock panels. DECORATION The strong highly-calendered manila face paper on Sheetrock Wallboard is suitable for any type of decorative treatment such as paint, texture or wallpaper and permits repeated redccoration during the life of the building. FREEDOM FROM EXCESS MOISTURE Sheetrock Gypsum Wallboard eliminates the use of tons of water on the job. Since excess moisture is not put into the house, the possibility of moisture damage is minimized. CRACK RESISTANT "Welded" together by Perf-a-tape Joint System. Sheetrock panels form walls and ceilings that are exceptionally resistant to cracks caused by structural movement, vibrations or minor settlement. UNIFORM QUALITY Sheetrock Gypsum Wallboard panels are factory-made products in which the raw materials and the manufacture are carefully controlled. SPEED OF ERECTION Homes in which Sheetrock Gypsum Wallboard is used can be quickly completed. SNUG FITTING TRIM Because of the uniform thickness of each panel, it is easy to install wood or metal trim snug and tight against the wall surfaces. NON-WARPING Expansion or contraction of Sheetrock under normal atmospheric changes is negligible and does not cause harmful warping or buckling. .t -V PLANNING THE JOB Planning is Ihc first step towards completing walls and ceilings. Prior to the assignment of a drywall application crew to a job. the individual structures that will receive SurcritocK Wallboard should be thoroughly inspected to be certain that all the trades who have previously worked on the job have com pleted their work in good order. A check should be made to determine if the necessary inspections have been satisfactorily completed. Ihc essentials of good framing as previously outlined on Page 6 should be accomplished. Builders usually assign to a capable carpenter in their employ the responsi bility of checking to see if studs or joists are out of alignment. Considerable emphasis should be placed on this work. Corrections should be made im mediately. Sueetrock Wallboard, when applied to studs and joists, follows the contour of the fram ing faces. If the framing is out of alignment, the surface of the wall will be correspondingly out of plane. If joists are out of alignment, 2"x6" leveling plates attached perpendicular to and across top of ceiling joists may be used. Toe nailing into joists pulls framing into true horizontal alignment and insures a smooth level ceiling con struction. BB026 1893 ESTIMATING LENGTHS AND FOOTAGE NEEDED Professional estimators have, from practical experience, developed many methods of determining footage required to complete various types of jobs. Basically, these methods stem from the simple principle of "scaling a plan", and determining the length and width and ceiling height of each room on the plan. Frequently, door and window openings are "figured solid" or no openings are included as openings. Exceptions may be large picture windows and large door openings. From these dimensions the estimator determines the square footage of each room. The footage of each room is added to determine the total footage required. From these figures, the lengths of gypsum wallboard needed may be determined. Generally, the professional has found that a maximum of three lengths of board are sufficient. The longest practical length of Sueetrock that will span the ceiling and wall area, eliminating butt joints entirely, or lengths that will result in the minimum number of butt joints to later be con cealed, should be used. Care should be taken where figuring walls adjacent to sloping ceilings so that the minimum amount of waste results and resulting waste pieces may be utilized elsewhere in the structure. In the event that the estimator or drywall contractor wishes to plot the wallboard layout graphically, sketches like the ones shown here may be made. Draw two horizontal lines crossed with two vertical ones. Close in the two ends and your layout represents ceiling and walls. Next, draw in doors and windows. Now indicate lengths of Sueetrock panels to be used. If ceiling height is 8'-3", or less, horizontal layout (at right angles to framing) of Sueetrock panels w'ill result in fewer joints, easier handling and less cutting. If ceiling height is greater than 8'-3'' or wall is 4' wide or less, vertical application will be more practical. Bowed or warped studs may be straightened by sawing the hollow sides at the middle of the bow and driving a wedge into the saw kerf until the stud is in line. Reinforce ment of the stud is accomplished by securely nailing F'x4" wood strips or "scabs" on each side of the cut. r 3 i '; VERTICAL LAYOUT V SELECTING THE MATERIAL There is a Siieetrock Gypsum Wallboard for every wall and ceiling need. Consult the Product Information chapter of this handbook for the selection of the type most suited to the construction requirements of the job. Job Storage If possible, the Siieetrock Wallboard should be ordered for delivery a day in advance of the drywall application. Materials stored on the job for a long period of time are subject to excessive abuse. The Sheetrock may be placed in the house. The material may be piled flat on the floor in the centers of the largest rooms. It is often desirable to place a select number of pieces of Siieetrock Wallboard in each room of the house. The Siieetrock planned for use on the ceilings should be placed on top of the pile for removal first. Piling long lengths on short lengths is apt to break the board due to the weight of the overhang of the longer board. This manner of storage should be avoided. An alternate method of on-the-job storage is that of placing the wallboard vertically against the framing. With this type of storage, however, some houses cannot be stocked until the electrical and plumbing installations are made. Caution should be exercised not to overload the framing members acting as a brace for this manner of storage and not to overload the floor space as a storage area when the board is piled flat on the floor. There are so many variable conditions of outside storage that in general outside storage of Siieetrock Wallboard is not recommended. If outside storage is absolutely necessary, contact the manufacturers of temporary covers or shrouds for their recommendations. A list of manu facturers will be supplied upon request. Under all temporary outside storage conditions the bed, possibly consisting of 2x4's lengthwise of the pile constructed with adequate crosswise support not more than 3 feet apart, should be raised from the ground a sufficient amount to provide circulation of air beneath the bed. No wrapping or shroud which is 100% effective is presently known. BB026 1394 PRINCIPLES OF SHEETROCK ERECTION Measurements All measurements should be carefully taken and be accurate. They should be taken at the approximate wall location of each edge or end of the board, whichever the case may be. Two measurements arc a cheek, one on the other, and it will usually warn the applicator of partitions or door bucks out of plumb so that allowances in cutting may be made. A twelve foot steel tape rule is recommended. Cutting the SHEETROCK Wallboard Straight line cuts across the full width or length of the board arc made by scoring the face paper, snapping the core of the board, and then cutting the back paper. The common took used to score and cut g>psum wallboard arc a Stanley wallboard trimming knife or a linoleum knife. Re gardless of the type used, the blade should alwats be kept sharp so tli.it the score will be made through the paper into the core of the g>psum wallboard. The use of a straight edge is recommended. An aluminum 4' T-square, ruled on both sides, facilitates clean, straight cuts. SCORING AND CUTTING Score the paper on the face of the board with a cutting knife using a straight edge as a guide. Break the gypsum core of tne SHEETROCK by snapping or bend ing away from the scored paper side. Complete the cutting by run ning the knife through the back paper from above or below. Smooth the cut edges with coarse sandpaper wrapped around a block of wood, a rasp, or trim with a cutting knife. 4 SINGLE LAYER SYSTEM Sheetrock Wallboard panels should be cut so as to slip easily into place. All joints should be loosely butted together. Boards should never be forced into position, as this will often cause one edge or end to override the other, resulting in a continuous ridge along the center of the joint. Tapered edges, except at angles, should always be placed next to one another. Butt joints should never be placed next to a tapered edge. To do so would result in a very difficult joint to conceal in the later stage of finishing with I'erf-a-iape Joint System. All ends and edges of Sheeirock Wallboard must be supported on framing members (except where end joints arc to be back blocked and floated--see chapter svsiems--"Back Blocking System"). Wherever possible, Sheeirock should be applied horizontally and in lengths to span ceilings and walls without end joints. If butt joints occur, they should be staggered and located as far from the center of the walls and ceilings as possible. SHEETROCK Wallboard Application-- Over-Under Windows; Over Doors In wall areas containing openings it is desirable, if practical, to apply Siieetrock Wallboard of sufficient length to span individual wall areas with large sheets, however, if it is necessary that joints occur near tin opening, the gypsum wallboard should he applied so that no vertical joints occur within 8'' of ex ternal corners of windows, doors or similar openings. Interior or exterior angles within the room excepted. Types and Spacing of Nailing Members Sheetrock may be applied directly over wood studs, joists and rafters. Wood Furring Sheetrock may be applied to wood furring strips -as follows: Furring strips over wood framing shall be 2" x 2" (nominal) minimum size. Where Sheetrock is applied parallel to furring strips securely attached to masonry walls, the furring strips should be 2" x 3" or I" x 3" (nominal) minimum size; where long edges of the Sheetrock are applied across the furring, the strips should be 2" x 2" or 1" x 2" (nominal) minimum size. Spacing of furring strips should follow the recommendations for maximum spacing of nailing members shown in the table below. Nails for application of Sheeirock over wood furring on masonry walls should not penetrate through the furring strip into the masonry. Special l'/n" long nails preferably CiWli-54 type (except for length) will be necessary for applying V" Sheetrock over 1" thick (nominal) furring. For application of panel Siir.EittocK over wood furring, see chapter sysiems--"Panel Sheeirock System." NOTE: The application of SHEETROCK over 1" thick (nominal) wood furring applied across framing members is not recommended since the relative flexibility of the furring during nailing prevents proper nailing and tends to loosen nails already driven. Maximum spacings for wood nailing members to receive Sheetrock Gypsum Wallboard shall not exceed those in the following tabic: WALLBOARD THICKNESS LOCATION APPLICATION METHOD MAXIMUM SPACING NAILING MEMBERS %" >/z" V?" %" %" Ceilings Sidewalls Ceilings Sidewalls Ceilings Sidewalls Horizontal Horizontal or vertical Vertical Horizontal Horizontal or vertical Vertical Horizontal Vertical or horizontal 16" o.c. 16" o.c. 16" o.c. 24" o.c. 24" o.c. 16" o.c. 24" o.c. 24" o.c. BB025 189t CEILINGS are applied first. Usually two men work on a ceiling, nailing from the center of the wallboard towards the ends and edges. SIDEWALLS are applied next. Where horizontal construction is used on walls, the top wall panel is applied first and butted against the ceiling. Vertical application should be used when the ceiling height is over 8'3", or where this method results in less waste or less joint treatment. TYPES OF APPLICATION OF SHEETROCK WALLBOARD Horizontal--Applying the long edges of the Sheetrock at right angles to the framing. Vertical --Applying the long edges of the Sheetrock Wallboard parallel to the framing members. Advantages of Horizontal Versus Vertical Application 1. Reduces lineal footage of joint treatment up to 25T. 2. Strongest dimension of board runs across framing members. 3. Bridges irregularities in alignment and spacing of framing members. 4. Better bracing continuity--each panel ties more framing members together. 5. Joints on walls are at a convenient height for the finishing operation with Perf-a-tape Joint System. ADHESIVE NAIL-ON SHEETROCK WALLBOARD CONSTRUCTION Siir.riROCK Brand Adhesive is specially formulated to adhere Sheetrooc (plain or insulating) to wood framing members in conjunction with supple mental nailing. The adhesive is of a rubber, resin type; plastic in nature. It is available in 5 gallon cans (approximate weight 52 lbs.). Meets Dry-Wall Adhesive Manufacturers Association Specifications. Sheetrock Brand Adhesive is .manufactured by Miracle Adhesive Cor poration, New York, N. Y. They have developed and pioneered many ad hesives used in the building field and were the first to market a dry-wall adhesive for nail-on attachment of gypsum wallboard. Sheetrock Brand Adhesive has unique characteristics. There is no other product that has all the necessary qualities provided in Sheetrock Brand Adhesive. Adhesion alone is not the predominant feature of adhesive nail-on wallboard attachment to framing. A product formulated primarily to provide adhesion will lack the other important qualities. The necessary qualities are as follows: 1. Bond. a. Contact adhesion--minimum droppings. b. Strength. 2. Resiliency. 3. Docs not detract from inherent fireproof qualities of gypsum wallboard. 4. No bleeding through decoration. 5. Retcnsion of bond on aging. 6. Uniform quality. 7. Workability. 8. Minimum delayed shrinkage. 9. Heavy body. a. Bridges irregularities. b. Provides maximum area of contact. c. Provides thick film. Advantages of Adhesive Nail-On Construction 1. 50% fewer nails--less nails to spot--less labor. 2. Reduces impact sound. 3. Reduces incidence of loose board due to improper nailing. 4. Bridges minor framing irregularities. 5. Resistant to moisture, vermin and heat. 6. Docs not detract from inherent fire resistance of Sheetrock Wallboard. Preparation All framing members should be in align ment. All plumbing, electrical conduit and receptors, fire blocks, backing, bridging, etc., should be flush with the plane of the framing members. All surfaces to come into contact with the adhesive should be free of dirt, grease, oil or other foreign material. 24 hours prior to application of the adhesive, it should be stored at a tem perature of approximately 70F. to facili tate ease of flow. Spacing of framing members shall be conventional for thickness of board used. Materials Sheetrock Brand Adhesive--approximately 2Vj gallons required per 1000 sq. ft. of Sheetrock Wallboard erected. NOTE: The film of adhesive, after nailing wallboard, should not exceed 1/16", which does not result in a sufficient reduction in the depth of the nail penetra tion into the wood framing to warrant the use of a longer naif to compensate for the thickness of adhesive. Equipment and Application Recommend USG Model A-3 Dry-Wall Admlsiw: Applicator. {V/i quart capacity caulking type gun has -Ik" nozzle cut to point at 45 angle!. Mechanically loaded (below--left) by Alemite Loader Pump Mode! 71'J7-1. clamped on Sheetrock Brand Adhesive pail. (Alemite Pump available from Alemite Co. distributors). Ames Mastic Meter (below--right) loaded with Ames Pump also recommended. (See chapter--tools). A continuous bead of Sheetrock Brand Adhesive is applied to the center of the face of all framing members which will be employed as a sup porting member for the gypsum wallboard. Adhesive is not required at inside corners, top or bottom plates, bracing or firestops, and is not ordinarily used in closets. On framing members where a joining of two adjacent pieces of wallboard will occur (ends or edges), a serpentine or zigzag bead pattern should be applied to permit proper bond when only half of the framing member's surface is initially covered. A-3 DRY-WALL ADHESIVE APPLICATOR AMES MASTIC METER Zigzag bead applied The size and shape of the head applied is partially dependent on the size and shape of the aperture in the tool used by the mechanic. In addition, the pressure built up within the tool (if any) may affect the amount of material extruded. A ptoperly formed bead should extend out from the face of the framing member a min imum of i" and contain a sulheient amount of material to spread over the entire surface of the framing member when the adhesive is (fattened to a thickness. I he proper foimntion of the head is most impor tant in achieving the desired results. No more adhesive should be applied than can be covered in a 15 minute interval. It contains volatile materials which may begin to evaporate and cause an initial surface hardness preventing full bond. DIAGRAM shows how the bead will spread over the stud face to about Winch thickness when it is com pressed by gypsum wallboard. This increases contact between the wallboard and framing members to create a more solid-sounding wall and acts as a leveling cushion between the two. As each piece of wallboard is put into place it should immediately be completely nailed, using the proper nail for the wallboard erected. Sup plemental nails arc required and should be spaced 16" o.c. on side walls and 12" o.c. on ceilings. Nails should be placed a minimum of %" from all cuds and edges and nails on adjacent panels should not be stag gered. If any adhesive is accidentally placed on an exposed surface, the ex cess should be removed. Although it may cause a discoloration, it will not bleed through a painted surface. There arc no asphaltic materials in Sucr.TKOC K brand Adhesive. Removal of Excess Material A petroleum solvent such as naptha, kerosene or white gasoline, should be used to clean tools or remove excess adhesive. Tools should be cleaned or they may be immersed in water to prevent hardening. Precautions Adequate ventilation should be provided. Normal precautions should be ob served with regard to fire, sparks and smoking. Unused portions remaining in the can should be rescaled or covered with a film of water which will temporarily prevent evaporation of thinners. All water must be removed prior to re-use. B3026 1397 THE DOUBLE NAILING SYSTEM Loose board may be the result of improper application procedures or lumber shrinkage. (See chapter--field froiilems for data relative to loose board and nails caused by lumber shrinkage.) By closely following the double nailing procedures, the danger of loose board caused by improper application is minimized. NOTE: Use of the Double Nailing System will not reduce the incidence or severity of nail pops due to wooJ shrinkage. The Double Nailing System was developed in 1954 and since then has been used on thousands of jobs with excellent results. The use of the second nail in close proximity (2") to the first, results in levs loose board due to carelessness--it is assurance that the board is initially nailed light. Based upon extensive investigations, we recommend the Double Nailing System. The Double Nailing System basically consists of nailing the hoard to each framing member with nails spaced approximately 12" o.c.--5 nails per 4' width for each nailing member plus an extra nail spaced approx imately 2" from each nail in the field of the board, making a total of eight nails for each 4' width of board. The sketch shows the correct finished nail pattern. Note that nails are spaced approximately T" o.c. at the ends of the board. Procedure proximately 2" from the first nails around the perimeter of the board. CEILINGS: Starting in the center of the board and working towards the edges and ends, nail the board to the ceiling joists with nails spaced approximately 12" o.c. Continue nailing the board with nails spaced 12'' o.c. until the board is sup ported. then proceed to drive the secondary nails ap driven. Only single nails are used SIDE WALLS: The picture illustrates the correct double nailing procedure on side walls. The board is first "hung" by driving edge nails at points "A," "B," "C," "D," etc. After the board is "hung," the mechanic com pletes the nailing in the se quence indicated in the picture. n * n \! II I ! ' GENERAL A. As the second nail in each group of two nails is driven home, the mechanic may observe movement between the board and the head of the first nail driven. Any movement indicates that the first nail was not holding the board tight against the framing and it should he given an additional blow or blows. B. Start nailing at the center of the board and work towards the ends. C. Hold the Sheetrock tight against the framing members while nailing. D. Check all nails for proper dimpling. E. Maximum spacing between nails in any one row is approximately 11". RESURFACING OLD WALL& CEILING SURFACES Where ceilings or sidewalls are so badly disfigured that an entirely fresh surface is desirable, they may be resurfaced using a layer of !V' or Ts" Smeetrock Wallboard. Remove all trim. (Ibis is not always necessary when using !4" SitrxiRocK). Remove all loose or poorly bonded material. Except when only small sections arc removed, voids must be brought out into a reasonably continuous plane with the wall surfaces by firmly nailing Smeetrock in place, cut to fit and shimmed out as required. SuKr.TKOCK is nailed through the old surface into joists and studs. Normally a fid cooler type nail should be used, but the nail must be of such length as to penetrate into framing members -Vn" minimum depth. Application of Vh" woodgrained Smeetrock over existing surfaces (walls) require VA" extra long matching colored nails (sec "Nail Specifications"--this chapter.) Joists and studs arc located by probing, and a chalk line is snapped to mark their full run. Where great irregularities of surface exist, furring strips should be applied not over lfi" o.c., using wood shingles to shim out to a true, even plane. Complete details on recommended nails and indl spacing for the triplication of SnrEtrock H'allhoard is found in this chapter under the heading--"Nail Specifications." ELECTRIC CUT-OUT OPENINGS Cut-out openings required for electrical switches, outlet boxes, etc., may be made with specially de signed cutting tools, so that die cut openings are produced to provide the exact shape of opening needed for various types of outlets. Detail at left shows use of one of several types of outlet box cutters. An alternate method of making cut-outs is accomplished with the use of a keyhole saw. (Sec chapter i nni s I APPLICATION OF PREDECORATED SHEETROCK WALLBOARD 33026 1898 Vh" Woodgrained Smeetrock is usually applied vertically because of the difficulty of successfully handling butt joints in a wall surface. I'rcdecoratcd Smeetrock is available in 4' widths and in T. S', and 10' lengths. 1W long colored nails are available to blend with each predecorated wall- board finish. Drive nails with a plastic headed hammer, a raw hide mallet, or with a regular hammer having pliable leather placed over the head. Nail spacing should not be less than -la" from ends or edges and spaced a maximum of 12'' o.c. on walls. Generally, predecorated Smeetrock is not used on ceilings; however, if so applied, nail spacing should be a maximum of 1" o.c. If the specific lengths used do not span the ceiling, butt joints will result. For this reason, it is not a practical ceiling finish. (See chapter product information-Td" Woodgrained Siileirock" for de tails as to additional decoration data and recommendations for the use of this material. See "Nail Specifications" section in this chapter for ad ditional information regarding colored nails.) ARCHES Arches of any radii are easily faced with Smeetrock. Score or cut through the back paper at approximate 1" intervals on a piece of Smteirock previously cut to the width and desired length of the soffit. REPAIRING DAMAGED SHEETROCK WALLBOARD Any wall may occasionally be subject to excessive abuse or heavy blows that will fracture or break the finished wall surface. Should Smeetrock Wallboard walls become damaged or broken, the fracture or hole can easily be repaired in the following manner; Inscribe an equilateral triangle on the wall surface large enough to cover the hole or broken area. (An equilateral triangle is one in which all angles and sides are equal. The triangle should clear the damaged section by at least one inch on all sides. Cut the triangular plug of damaged Smeetrock Wallboard from the wall with key hole saw, sloping the edges of the plug inward at a 45 angle. A similar triangle of the same size should be prepared from a piece of Smeetrock Wallboard of like thickness. Again cut all sides inward at a 45 angle. Shape the plug to a loose fit with a sanding block and tl sandpaper. Butter all edges of the plug with Perf-a-tape Cement and fit it to the wall opening. Apply Perf-a-vape Joint System to nil joints and finish in the manner recommended for a butt joint. The equilateral triangle is recommended to save time in fitting. As all sides are equal, the new plug will fit the wall opening regardless of its orien tation. Damaged areas of Smeet rock walls treated in this man ner arc permanently repaired and concealed. NAILS AND NAILING One of lhe most impoitmil steps in the pioper nppliealion of n Situ.trock Wallhorud joh is the nailing of the Siiiliuikk to the framing members. Knowledge of the l>pe of nail and nailing pioeedme is vital if a good joh is to he assmed. It is olnions that the nail selected must have snllieient holding power to keep the hoard in place. 15 m " (5d) and I 'h " (dill cement coated and hright finish cooler type nails base been Used for the application of j" and Sin unni k Wall- hoard for many years and have proven that their holding power is adequate. I he holding power of these nails was determined to piovide a yardstick for designing a shorter nail which would have suflieienl "in .service" hohliiu; power. l-istensise experiments have shown that the holding power of an annular ring nail with an over-all length of 11 r " is approximately equivalent to that of the I 1 2" cement coaled cooler type nail. I litis the I'i" annular ring nail satisfies the holding power requirements ami its use results in reduced penetration of the lumber and less exposure of the nail shank due to subse quent wooil shrinkage. The figure below illustrates a comparison of the penetration of the wood by a l?n" nail anil a I'i" nail. The 1%" nail penetrates the wood %" deeper than the 11T " nail, or 50r,c more. T herefore, we can expect that the additional exposure of the l5'x" nail will be approximately 50rr more than the I'i" nail under similar wood shrinkage conditions. The diameter of the shank of the nail appeals to have little or no affect oil nail behavior. Authorities are in some disagreement on the effect of the design of the shank (annular ring versus plain shank versus other designs) on the reduction of nail exposure. It is the opinion of the majority that there is little, if any. difference. However, the annular ring design is advantageous because the prettier hohiinp power of sitth n tlesipn permits the use of shorter nails. NAIL SPECIFICATION CHART BB026 1899 For %" SHEETROCK and %" BAXBORD (Where No Specific Fire Rating Required) \y." Annular Ring Nail (Specifications Same as GWB-54 Except 13/a" in Length) Space a maximum of 7" on ceil ings, 8" on walls: approximately 315 nails per pound. 4Vi lbs. per 1,000 sq. ft. For y2", 3/a" and */4" SHEETROCK; %' and >/2" BAXBORD Backing Board \ l>/" GWB-54 Annular Ring Nail, Flat head, Vi" Dia. Slightly Countersunk, .098 Gauge, Bright Finish, Vz" Clearance at Head, 20 Rings per Inch. Medium Space a maximum l'f on ceilings, 8" on walls; approximately 555 rails per pound. 6Vi lbs. per 1.000 sq. ft. Alternate Nail for W SHEETROCK Wrdlbcard I t r-------......................... '------------ 1 yB" 5d Cooler Type Nail (Bright Finish) Space a maximum 7" on ceilings, 8" on walls, approximately 504 nails per pound, 6 lbs. per 1,05') sq. ft. Alternate Nail for 3/8" SHEETROCK !===- l3/e" 4d Cooler Type Nail (Bright Finish) Space a maximum 7" on ceilings. 8" on walls: approximately 488 nails per pound, 4:,.- lbs. per 1,000 sq. ft. Alternate Nails for *4" SHEETROCK *_ 1 %" 4d Cooler Type Nail (Bright Finish) For direct application to framing. Space a maximum 7" on ceilings. 8" on walls; approximately 4S8 nails per pound, 4'/< lbs per 1,000 sq. ft. NAIL SPECIFICATIONS The chan on next page indicates nail specifications and nail spacing recom mendations. Additional nail spacing recommendations pertaining to the Double Wall System, Siillikock Wallhoard--Truss t I'.u Stud Partition System, and Panel SllLEiitotK System will be found under the chapter svsirxrs. Also see chapter--misclli aneous aim'lication Miniums. t--------------------------------------------- l7/9" 6d Cooler Type Nail (Bright Finish) For use o.er existing surfaces Space as above: approximately 275 nails per pound. 6!i lbs per 1.000 sq. ft. For s/g" SHEETROCK F1REC0DE 60 (Where 1 Hour Fire Rating Required) 1% 6d Cement Coated Cooler Type Nail Nailed to wood framing members' space 6' on ceilings. T' on walls. 275 nails per pound. 6',i lbs. per 1.000 sq. ft. For y2 SHEETROCK FIRECODE 45 (Where 45 Minute Fire Rating Required) I 5d Cement Coated Cooler Type Nail Nailed to wood framing members: space nails 6" on ceilings, 7" on walls; 275 nails per pound, 6l/ lbs- per 1,000 sq. ft. For %" BAXBORD or SHEETROCK FIRECODE 60 j --vmrn'1Nrrn'Ti'^ I No. 11 ga. 1V*" Fetter Ring Annular Type Nail Vis" Head For use with nailing channels: space 6" o.c. on ceilings; approximately 355 nails per pound, 6% lbs. per 1,000 sq. ft. For Woodgrained SHEETROCK and Striated Finishes --ll/a" Predecorated Nail For use with all predecorated SHEETROCK, matching colored nails; space 12" o.c. on walls; approx. 840 nails per lb., 2 lbs- per 1,000 sq. ft. 17/b" extra long matching color nail over existing walls; 350 nails per lb. 7'/? lbs. per 1.000 sq. ft. (16" wide), 5 lbsper 1.000 sq. ft. (4' wide). For %" Plain Panel SHEETROCK b= l`/a" 3d. 1S* Ba- **' Flath- fooler Type Nail For use with Plain Panel SHEETApproximately sWnaifs per ptnjnd* 3 pounds per 1,000 sq. ft. ' While the spacing of the nails is most important, care should also be taken in their placement. Nails should be driven not less than %" from ends or edges of Sheetrock. Nails on adjacent ends or edges should be opposite each other to assure edge comformation. Nailing should be accomplished from the center of the Sheetrock Wallboard toward the outer ends or edges. While nailing, apply pressure on the wallboard adjacent to the nail being driven. The use of a crowned head hammer or a Wxl-Boxkd hammer (see chapter tools) is recommended. Drive nails with the shank reasonably perpendicular to the face of the board. With the last blow of the hammer, seat the nail so that the head is in a slight uniform dimple formed by the last blow of the hammer. Do not break the paper at the nail head or around the circumference of the dimple by over-driving. Maximum depth of the dimple should not exceed 1/32". After the board has been completely installed, inspect by pounding on walls to detect rattles which indicate loose nails, and by pushing on the board adjacent to nails to see if there is any movement. If loose nails are detected, drive them tight. Whenever nails have punctured the paper, hold the board tight against the framing and rcnail properly approximately lfi" away from the nailhead which punctured the paper. 27 BB026 1900 improper application procedures NAIL HEADS PUNCTURING FACE PAPER Fig. 1A--Nail heads have punctured paper and shattered core of the board. Such nails have very little grip on the wallboard and will very likely cause a nail pop. Fig. IB--A properly driven nail. Xote slight uniform dimple--with nail hciid bearing on paper and holding the g\psum wallboard tccureh again\t framin'.' member. FIG. 2. LACK OF PRESSURE ON BOARD DURING NAILING It is impossible to align all studs or joists perfectly, be cause of minor bowing and warping of individual fram ing members prior to erection. Ihc h" Ik*.id of the nail alone Cannot be relied upon to pull the wallboard into firm contact with all uneven framinu members - additional pressure is needed. Dunne final blows <./ the hammer, apply ample pressure with the hand on face of board adjacent to find (Fig. 2) to bring board m firm contact with nailing member. 1t _ FIG. 3. BOARD IMPROPERLY FITTED Fig. 3--Board wedged into place--it is too long for the space intended. Back of board cannot be brought into natural contact with the framing. In all probability a high percentage of nails on the central ` uds will puncture the paper. Board\ like this should he remo\ed and replaced u/// hoti/ds cut to fit piopeth. Sfj i 4. I. .. --. , j ------- =--:-- Jr- NAILING FROM ENDS AND EDGES TOWARD CENTER Fig, 4 illustrates what can happen when the practice of nailing from ends toward the center is followed. Obviously, if the ends of the board are securely anchored, it will be impossible to bring the back of the board into contact with the f.'.e of the center nailing member. Howe\er, by starting to nail on center framing mem ber and proceeding towards each end or edge, board can be brought i`i:o font contact with all nailing surfaces. ____ / sK 1 FIG. 5. PaBUTiO" \k i/'i` - .. .. ..V FRAMING MEMBERS OUT OF ALIGNMENT i '' Framing members which are more than lj" out of alignment with reject to adjacent members (as illustrated in Fig. 5) also cause a situation in which it is diflicult to bring the back of the board into firm contact with all nailing surfaces. Before beginning the application of board, the alignment of studs <md joists should be checked, ami corrections made hcrc\er r.ecis<ar\. In ad Utmn to reducing nail pops, this procedure will result in s'i\uerncr ua;/\ <<r icding*. FRAMING MEMBERS TWISTED Figure 6 illtislr.ucs \v;illho;irri applied (o a flam ing member which has not been properly squared with the plates. In nailing tire hoard to this member, there is danger of puncturing the paper with the nail head. There is also the danger of a re\ersc twisting of the member as it "dries out," in which case the board will be loosely nailed and a pop will occur. All twisted studs should he squared before the application of wallhoard. IMPROPERLY ALIGNED STUDS, JOISTS OR HEADERS u-V Figure 7 illustrates a misaligned top plate and stutl. II mimering in the areas indicated by "X" will probably result in the nail heads puncturing the paper or cracking the board. Focn though the paper is not punctured, the chances of a pop are far greater than if the stud ami plate had been properly aligned. Studs, plates or heatlcn which are not in alignment should be conected heftnc the appheatum of the hoard. If necessary, the faces oj the studs or plates should he shimmed out flush with adjoining surfaces. FIG 7 WALLBOARD APPLIED OVER PROTRUSIONS Figure 8 illustrates bridging projecting beyond the face of the joist. This projection will prevent the back of the board from being brought into contact with the nailing sin face. Nails dri\cn in the area of the protrusion will propably puncture the face paper. Headers, lircstops or various mechanical installations can create similar situa tions. Before applying hoard, make certain that there are no materials projecting beyond the plane of the nailing surface. / V, /- . / /, < / // / /* A \//- NAILS INSECURELY DRIVEN Figure 9 illustrates nails not properly anchored. If the nails arc not properly anchored within the wood framing member, vibrations from doors closing, bumps against the wall or sounds may work the nail loose, causing a nail pop. Nails that miss framing members or are not secure should Ire iemo\ed promptly, and a new nail driven properly. FIG 9 BOWED STUDS--IMPROPERLY PLACED JOISTS A badly bowed stud, a highly crowned joist or a joist placed with the crown down creates a situation in the area of the bow similar to a framing member badly out of alignment. Badly bowed studs may he detected during the alignment check and should he straight ened within reasonable limits. All ced ing areas should he checked for alignment and proper crooning of joisis, and adjustments made. NAILS LOOSENED BY POUNDING Occasionally when board is applied to the second side of a partition, the dri\ing of the nails will tend to loosen the nails on the opposite side. This is particularly true when lightweight, soft lumber or undersized studs (2x3 or under) are used. A good practice is to check the tightness of the hoard on the side of the partition where the hoard was first applied. If looseness is delected, strike each nail head an additional blow with the hammer. TREATING JOINTS AND CORNERS WITH PERF-A-TAPE JOINT SYSTEM B' :02 Mixing the Cement Mix Perf-a-tape Cement in a clean, metal container. A 1" x 2" I 4' long) makes a convenient wood mixing paddle or the common couur.cn ial potato masher is effective. Power mixing saves considerable time, particularly where mixing in a central location is convenient. Power may be supplied by a Vi" heavy duty electric drill operating on 115 volts AC-DC at not oxer 400 R.P.M. (200 to 300 R.P.M. even better). Drills operating at high speeds whip air bubbles into cement. Mixing paddles may be of many variations. (See chapter TOOLS). Mix clean, lukewarm water (not hot) in the proportion of 1A12-1 71 i pints per 25 lbs. of powder for hand application; up to. but SOT Ol'T.R 191/' pints for machine application. Add the powder to the water. Stir vigorously for several minutes: make sure all cement is uniformly damp. Allow the mix to soak for 30 minutes (longer at lower temperatures) to allow proper solution of the material. DO NOT OVER-THIN CEMENT WITTT WATER. Excess water will not acctlernte the solution process although the cement may appear to be in a workable consistency. Over thinned or "soupy" cement often leads to excessive or delayed shrinkage as well as bond failure. A final short mix prior to use is necessary to properly disperse all the materials ir. the cement. IMPORTANT: Add nothing to Perf-a-tape Cement except clean water; otherwise, the bonding quality may be seriously affected and a ioh failure may result. CAUTION: In cold weather heat must be provided both day and night prior to and during the entire joint treatment operation. A minimum temper ature of 55' F. is required at all times until the cement is completely dry. Ventilation should be provided to eliminate excessive moisture. In glared buildings, this may be accomplished by keeping windows open approxi mately two inches top and bottom (or side pivoted windows approximately four inches) to provide air circulation In enclosed areas lacking in natural ventilation, temporary circulators should be used. Under slow drying con ditions. allow additional drying time between coats of cement. Axoid di.ffts during hot. dry weather to prevent too rapid drying. (See chapter Fit I o problF.ms--"Cold Weather Tips--Perf-a-t\pe Joint Sy'-tem Product-. .1 Buttering the Joints Check all nails. Protruding B3026 1902 nails in the field of the hoard should he driven home, leaving a dimple in the surface paper of the Siieetrock Wallboard to receive Perf-a-tape Ce ment. Rutter the Perf-atapf. into the channel formed by the tapered edges of Sheet roc k Gyp sum Wallboard, tilling the channel fully and evenly. Avoid heavy fills. f ix Spotting Nail Heads Apply the first covering coat of cement over all nail . heads immediately prior to or after embedding tape. Use sufficient pressure on the knife to finish cement level with wall surface. . Spot nail heads in a simi lar manner during the sec ond coat application of ce ment over joints. During the application of the third coat over the joints, Embedding the Tape sand nail heads lightly and apply a third finishing coat oser nail heads to level any defects. Allow cement over nail heads to completely dry. Light sanding may be necessary before decoration. Center the Perf-a-tape re inforcement and press it down into the fresh ce 7 ment. By holding knife at an approximate 45" angle to the board, draw knife along joint with sufficient PERF-A-TAPE Topping and Finishing Materials pressure to remove excess cement. Leave sufficient ce ment under the tape for proper bond but not over }'m" under feathered edge. Do not use topping or fin ishing cement for embed Perf-a-tape Topping or Finishing Material is used for finish work only. This easier sanding, smoother working material is available only in 25 lb. bags. Most professional applicators prefer this material for second and third coats and especially for spotting nail heads on all three coats. Pi iu -atape Topping or Finishing may be applied over Perf-\-bl\d or Dur-a-hem) external corner reinforcement. (See chapter xif.tvl products accessokiiI ding tape. Covering the Tape As soon as the tape is em bedded. cover with a thin layer of cement to fill the recess between the tape and the board surface flush with the board. Second Coat Application Alter the embedding and coveting coat is completely dry (under good drying conditions. 24 horns) ap ply second coat. Icmhcicd beyond edges of lii't coal approximately one and one-half inches Third Coat Application Alter second coat is dry, sand lightly. Apply a thin `finishing" coat to joints, f eather joint edges tin inch or two beyond second coat. Sand lightly when dry. Finishing Corners INSIDE: Fold tape along center crease. Butter both sides of the corner with Perf-a-tape cement and apply the tape. Apply the second and third coats of cement in the same man ner that you would use to finish fiat joints. OUTSIDE: Use Duk-a-uead (as shown) or Perf-a-head corner reinforcement for all outside corners. (Con sult chapter metal prod ucts accessories for product and application details.) ALL PURPOSE READY MIXED PERF-A-TAPE CEMENT B3025 1903 All Purpose Ready Mixed Perf-a-tape Cement is the ideal material for the reinforcement and concealment of joints in gypsum uallboard construction as well as covering nail heads and forming interior and exterior angles. Advantages Ready mixed--no job mixing--saves time and effort. Outstanding coverage. Excellent bond. Less shrinkage--especially on nail heads. Pleasant odor. Non-irritating. Practically no droppings--eliminates costly job cleanup. No waste--use what's needed-- replace the lid. Fast tool cleanup--cleans easily with water. Extra smooth finish--good workmanship makes most sanding unneces sary. Sands easier than powder cement. Tends to minimize ridging. No paint discoloration--will not burn through paint. Recommendations for Use 1. Store in warm place before use. 2. If any liquid has separated from cement, remix before using. 3. Normally thinning is not required. 4. Allow cement to dry thoroughly between coats. Overnight drsing is usually sufficient. Spot nail heads as required. In some cases two coats will be sufficient. xfeyiv1#t-w. -Wiif-.iit ALL PURPOSE READY MIXED PERF-A-TAPE CEMENT-PROFESSIONAL APPLICATOR USE All Purpose Reuc.lv Mixed Cement is packaged in a polyethylene bag enclosed in a 5-gal. corrugated carton. Advantages 1. Available in two consistencies; one for hand application and the other especially designed for Ames tools. 2. A 3 in 1 material out of one package . . . embedding, topping and texturing cement. 3. Easier sanding, l.ow shrinkage. 4. Better slip--a butter-like property. 5. Less tendency to surface crust. 6. If thinning required for use with mechanical tools, the addition of water can easily be made and mixed with a potato masher type tool (sec chapter --TOOLS ) . 7. Extra smooth finish. Minimized sanding required especially on feathered edges. 8. Has package life of I year--longer under ideal storage conditions. Ames tool formulation has package life of 60 ilays. 9. Compatible with Perf-a-tape powder cements. Thorough "clean-out" of tools and containers to avoid contamination no longer necessary. Use ns a Topping over thoroughly dried powder cement or as taping cement when powdered Perf-a-tape Cement is used as a Topping. Limitations Ready Mixed Perf-a-tape Cement products must be protected from freezing and arc sensitive to cold weather. If material becomes frozen allow it to thaw at room temperature (do not force the thawing process). Retemper and it will again be usable, unless it has been subjected to several freeze-thaw cycles. HOW TO REPAIR PLASTER CRACKS WITH PERF-A-TAPE JOINT SYSTEM AND ALL PURPOSE READY MIXED PERF-A-TAPE CEMENT Large structural cracks and cracked interior corner angles in plaster can be readily repaired with Perf-a-'iape Joint System or All Purpose Ready Mixed Perf-a-tape Cement. In remodeling or redecorating old plastered surfaces, it gives lasting concealment and reinforcement to disfiguring cracks. The strength of Perf-a-tape Joint System helps assure enduring conceal ment of cracks in old plastered walls. Merely filling large cracks with a putty type material will not usually provide the reinforcement needed to prevent reopening. Remove all loose material. Sand a 12" wide area around crack. "Butter" it with cement; embed Perf-a-tape Reinforcement. Finish with two coats of cement for a strong, smooth surface. Occasionally pits or craters may develop in the cement as it dries due to application over a well sealed surface. These are not cause for alarm, as the pits are easily filled on the final thin skim coat. Order Perf-a-tape Joint System in handy 60' packages containing 60' of tape and 4'A lbs. cement; or large economical 250' bags containing 250' of tape and 18 lbs. of cement. Tape is available separately in 60', 250' and 500' rolls. Field Problems CONTENTS NAIL POPPING--DEFINITION AND CAUSES..................................... PAGE 32 LUMBER SHRINKAGE AND RESULTING NAIL POP......................... 32 REPAIRING NAIL POPS......................................................................... 35 SHEETROCK WALLB0ARD PROBLEMS............................................. COLD WEATHER TIPS--PERF-A-TAPE JOINT SYSTEM PRODUCTS 36 40 mm l904 o -u S3 S</> NAIL POPPING: DEFINITION AMD CAUSES The use of drywall has increased in volume as the efficiency of drywall mechanics developed, and its use has spread from low cost housing to the most expensive homes. This has resulted in greater over-all perfection of the finished job as a normal requirement. As more serious difficulties have been overcome, the problem of nail popping has become relatively more important. A nail pop is 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 head of the nail 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 popping may occur with any type of material secured to wood with nails. The same principles which cause nail popping in gypsum wallboard construction also apply to any other type of construction where nails are used. Causes: Whenever the back of the gypsum wallboard is not heldreasonably tight and secure against the face of the framing member by thehead of the nail, a potential nail pop exists. Figure 1 shows gypsum wallboard held reasonably tight and secure against framing member. Figure 2 shows the board spaced away from the framing. Visualize an inward pressure on the face of both boards and you can readily see that the nail head in Figure 2 will push through the thin covering pad of cement to produce a protruding nail or nail pop. In Figure 1, movement of the face of the board with relationship to the head of the nail will not take place; hence no pop will occur. The condition which is illustrated in Figure 2 will henceforth be referred to as a "loose nail". LOOSE NAILS ARE CAUSED BY: 1. Improper application procedures. 2. Lumber shrinkage. 3. A combination of 1 and 2. Sec section "Improper Application Precedures" in chapter--board application and finishing which is a compilation of pertinent data and information which is also relative to the con ditions which cause loose nails. LUMBER SHRINKAGE AND RESULTING NAIL POP When wood penetrated by a nail shrinks, the nail tends to protrude from the wood. (This condition is sometimes referred to as "nail creep".) The emer gence of the nail or increased exposure of the nail shank results in loose nails--the basic cause of nail pops. Here is an explanation of this condition. Characteristics of Wood Shrinkage Framing lumber as commonly used has a moisture content in the range of 15% to 19%. However, individual pieces may be considerably higher or slightly lower. Wood having a moisture content at the time of construction in the 15% to 19% range may, in service, eventually reach a moisture content of from 5% to 10%, except in the damp Southern coastal states and the dry South western states, where the ranges may be 8% to 13% and 4% to 9% respec tively. Thus, when wood is framed into a building and the building is put into service, the framing lumber loses some of its moisture content. After the lumber has eventually reached equilibrium with surrounding conditions, there will be only minor residual increases and decreases in its moisture content. B325 2905 The important fact to he established here is that the first and by far ike ftreatest change in moisture content usually occurs during the first year after construction. Living wood may contain from 30% to 300% of water. This water is divided roughly into two parts--free water in cell cavities and water ab sorbed by the capillaries of the fibers and ray cells. When all the free water has been removed and the absorbed water remains, the wood is said to have reached the fiber saturation point, which is approximately 30%. Wood shrinks as the moisture content of the wood is reduced below 30%. Very little, if any, shrinkage occurs for reductions of more than 30% in moisture content. As the moisture content of a piece of wood is reduced below the fiber saturation point, the unit of shrinkage is fairly uniform, being approximately of the total shrinkage which may occur for each 1% loss of moisture content. Wood shrinks most in the direction of the growth rings (flat grain) some what less across the growth rings (edge grain: see Figure 3) and very little, as a rule, along the grain (longitudinal!) ). Generally, heavier pieces of the same wood species shrink more than the lighter ones. (These characteristics often account for a concentration of nail pops along the length of a particular stud or joist.) Under job conditions, the gypsum wallboard 1' 1 .____ i_ - is usually applied within two to four weeks after the building has been enclosed. During this period the framing will dry out to a certain 1 I'i extent, depending upon drying conditions. How ever, even under the most favorable drying T -i -- conditions and four weeks exposure, it is doubt ful that the moisture content of the framing \ "L" \ \ r. -h Ti ~~ -- will reach a percentage as low as that which will occur "in service." (The authority for the preceding is U.S. Hat gbain EDGE GBain Department of Agriculture publication. Wood FIG. 3. Handbook No. 72, in a section titled "Control of Moisture Content and Shrinkage of Wood." It is obtainable by writing to Supt. of Documents, U.S. Government Print ing Office, Washington 25, D.C.) Each increment or part of a mass of wood shrinks at a fairly uniform rate. Shrinkage in a mass of wood is towards the center. The movement of any point on the wood or boundary, such as an outer surface towards the center, is equal to the total of the shrinkage of each increment between that point or boundary and the center. For example, in Figure 4 we illustrate a mass of wood 4" wide by 2" thick divided into T' increments. For purposes of illustration, a total of Vu" shrinkage has been selected for each 1" incre ment under conditions wherein the moisture content has been reduced from 19% to 10%. The outer plane of Areas "A" has moved yu" closer to the horizontal center line. The outer sur face of Areas "B" has moved Is" closer to the hor izontal center line ('/,*" for the shrinkage in Areas "A" plus '/,s" for the shrinkage in Areas "B"). Similar pro portionate shrinkage also oc curs in relationship to the vertical center line. 11 FIELD PROBLEMS Effect of Wood Shrinkage on Nails IMPORTANT NOTE: The dimensions used in Figures 6 to 8 inclusive arc selected only for con venience to illustrate principles and :ire not to be construed as actual measurements. The left hand drawing Figure 5 represents the cross section of a piece of framing lumber with a moisture content of 19% through which has been driven a steel rod with both ends sheared off flush with the surface. The right hand drawing represents the same piece of wood after the moisture content has been reduced to 10%. Note that the shrinkage of the wood has resulted in a movement of each outer edge surface of the wood Va" towards the center line, also, that the steel rod pro trudes from the lumber on each edge Va". 'r 1 L: . _____ fig. 5. Figure 6 illustrates the same conditions as in Figure 5 ex cept that nails have been driven different distances into the 19% moisture content wood, one nail penetrating 2" and the other 1". The sections of the nails pro truding from the wood were then sheared off flush with the surface as illustrated by the drawing on the left. In the drawing on the right, the wood penetrated by the 2" section of the nail shrank Va", resulting in an exposure of Va" of the nail shank. In this same drawing, note that the wood penetrated by the 1" nail shrank resulting in an exposure of the nail shank of only The yu" shrinkage of the wood between the point of the l" nail and the center line resulted in the nail's moving y,," towards the center line. In Figures 7 and 8 we illustrate Vt" gypsum wallboard attached with nails having a penetration of 2" and 1" respectively. The figures on the right show how the emergence of the nail due to wood shrinkage creates a space between the back of the board and the nailing surface. A comparison of the distances between the backs of the boards and the nailing surfaces of Figures 7 and 8 shows that the use of the shorter nail resulted in a smaller space between the back of the board and the nailing surface. Extensive experiments conducted by Forest Products Laboratory and Pur due University have shown conclu sively that the recession of the wood nailing surface from the nail head is almost in direct proportion to the depth of the penetration. That is, the longer the nail, the greater the ex posure of the nail shank; the shorter the nail, the less the exposure of the nail shank. -F- t C! 4 FIG. 8. J--f Nail Pops Due to Wood Shrinkage BB026 190b As previously shown, as the framing lumber shrinks the distance between the head of the nail and the nailing surface of the framing member in creases. Assuming that the nail originally held the gypsum wallboard reasonably secure against the framing, the board is held less securely after the framing has shrunk. If the additional nail shank exposure is in the range of 'At' (.0625) to (.03125) the board will no longer be held tightly against the framing. This is the condition (loose nail) which is the basic cause of nail pops. Fortunately, minor emergence of a properly driven nail (up to .005") seldom results in a visible pop. Were it not for this, nail pops due to lumber shrinkage would be much more common. Nail pops of the magnitude of .004" to .005" may be objectionable when they occur in a surface painted with a smooth, uniform paint film or a surface having a gloss or semi-gloss paint finish. If the surface is painted or treated with a paint or material that has some grain or texture, pops of minor magnitude will be somewhat less visible. Many pops have been measured and, as a matter of interest, they range from .003" to .022". The latter, of course, are very unsightly. Actually, pops of over .006" arc usually considered objectionable. REPAIRING NAIL POPS When to Repair Nail pops which are apparent before or during decoration should be re paired immediately. In all probability, they are caused by improper job procedures. Nail pops which occur after one month's heating or more are, in all probability, caused by shrinking lumber or a combination of shrinking lumber and poor nailing. These should not be repaired until near the end of a heating season. If the pops are repaired before the lumber has shrunk sufficiently, further shrinking may occur; as a result, the pops may re appear---even if to a lesser degree. How to Repair Using the proper nail for the thickness of wallboard used placed approxi mately \Vi" away from the popped nail, drive it in the prescribed manner while at the same time applying sufficient pressure against the hoard adjacent to the nail head to bring the board in firm contact with the fram ing. Strike the popped nail with a light blow or blows as required to seat it below the surface of the board. Remove loose cement and then apply finishing coats of joint cement and paint. Will Pops Recur? If the framing lumber has been subjected to a full heating season, the chances are good that the lumber has reached a moisture content approach ing the lowest point of its equilibrium range. During the following spring, summer and fall seasons, the lumber will undoubtedly pick up some moisture and swell to a degree. During the following winter's heating there will again be a loss of moisture content and subsequent shrinkage. Although there are no factual data on what actually occurs, it is believed that the seasonal fluctuations are, except in unusual cases, in the ranee of not more than 2% to 4% moisture content differences. Under these con ditions, the movement is so slight that there is little danger of future pops. F ltlD PR0BIFMS SHEETROCK WALLBOARD PROBLEMS It is to your advantage to know and understand certain conditions which may adversely affect the quality of the finished job. Irregularities which arc the result of joint treatment will occur in a straight line pattern. These can be caused by starved joints, joints on twisted studs, joints on high studs or joists, boards out of plane, joint finishing in which de layed shrinkage has occurred, or any combination of the above. Cements used for joint finishing are a "drying type" material and therefore harden as the contained water is evaporated. As they dry, their volume shrinks. The shrinkage is proportionate to the amount of water used in mixing the cement (consistency) and also to the depth of cement application. Watery cement and deep fills will obviously shrink more than heavy cement and shallow fills. Three coats of powder cement should be applied over joints and nail heads, though ready mixed material may only require two coats over nails or outside angles; and, in all cases, the underlying coat should be dry before application of the next coat. JOINT TREATMENT CONDITIONS Starved Joints High Joint CAUSE Delayed shrinkage -- caused principally by the failure to allow each coat of joint cement (and under lying board paper) to fully dry before applying the next coat of cement or before painting. Un der the above condi tions joint cement shrinkage progresses until drying is com plete. Insufficient cement applied over tape to fill channel formed by tapered joint -- Cement too watery -- I nsuff icient drying time be tween successive lay ers of cement -- Over sanding. Needless piling of cement in channel. Cement not feath ered out beyond shoulders -- Insuffi cient or no sanding. REMEDY OR PREVENTION Apply full covering coat (1st) of cement over tape immedi ately after embed ding since this will be the heaviest ap plication of cement. Most of the shrink age will take place in this coat making it easier to properly fill channel. Sand joints to a flush surface. Opposite of "starved joint" above. Framing out of alignment contrib utes to this problem. (See "Framing Re quirements" and "Improper Applica tion Procedures" in chapter -- BOARD APPLICATION AND FINISHING.) Corn'd. JOINT TREATMENT CONDITIONS Blisters in Tape Edge Crack in Tape Adjacent to Tape Edges Cracks in Inside Corners Paint Discoloration CAUSE Insufficient cement under the tape -- Tape not initially pressed into good contact with the cement. BB026 1907 REMEDY OR PREVENTION Open up blistered area by slitting tape. Fill cut with joint ce ment and press tape back in place with knife blade.When dry. sand to a smooth level finish. FIELD PROBLEMS Improper application -- too fast drying conditions -- too deep a fill under tape -- cement mixed too thin. Do not apply PERF-ATAPE Joint System over hot surfaces caused by hot pipes, radiators, salaman ders. In hot dry weath er avoid application in drafts and prevent radical changes of temperature and humidity by control ling ventilation dur ing the drying cycle. Repair cracks as soon as they appear and when cement is dry, by grooving out crack with a sharp tool to remove all loose ma terial. Apply a coat of shellac to this grooved area. When dry, fill with PERF-ATAPE Cement. Too much cement over the tape at apex of angle. Wipe down corners correctly leaving only a small amount or no cement in the apex. Painting over a joint before it is complete ly dry throughout. No painting should be done until all ce ment is thoroughly dry. In cold damp weather this may re quire 48 hours or more. Corn'd. .17 NEED PROBLEMS JOINT TREATMENT CONDITIONS Nail Pops Nail Spots CAUSE See '"Framing Re quirements", "Nails and Nailing", chapter -- BOARD APPLICA TION AND FINISH ING and "Lumber Shrinkage and Result ing Nail Pop", chap ter -- FIELD PROB LEMS. REMEDY OR PREVENTION See "Framing Re quirements", "Nails and Nailing", chapter -- BOARD APPLICA TION AND FINISH ING and "Lumber Shrinkage and Result ing Nail Pop", chap ter -- FIELD PROB LEMS. JOINT TREATMENT CONDITIONS Damaged Edges Due to a greater dis sipation of heat directly over the nail head, a deposit of dirt (dust particles) may accumulate over the nail heads in out side walls and top floor ceilings. Nail spots are great ly minimized in the Double Wall System using SHEETROCK Wallboard because face layer nails are removed. In single layer construction, the spots can be washed off enameled sur faces, removed with wallpaper cleaner or surfaces affected may be redecorated. The severeness of spotting will be di rectly proportionate to the cleanliness of the air within the house, and to tem perature differences between the framing and the room side of the board. Compressed or Forced Boards CAUSE Paper-bound edges of gypsum wallboard damaged or other wise abused results in a loosening of the paper from the gyp sum core, a ply sep aration along the paper edge as well as a certain fractur ing or powdering of the core itself in this immediate area. Even when not com pressed, these dam aged portions of the board edges are seemingly more sus ceptible to expansion of the paper surfaces upon wetting, there by tending to con tribute more readily to the ridge when joint system is ap plied. 3B026 19^8 REMEDY On PREVENTION Avoid butting t o gethersuch edges that may easily be compressed. Handle SHEETROCK with reasonable care. Any severely damaged edges should be cut back to sound board before application. Boards that have been forced irto place or nailed op posite to the recom mended procedure will often buckle causing one end or edge to over-ride the other. Cut SHEETROCK Wallboard so as to slip easily into place. Nail from center of the board toward the ends and edges. Ap ply pressure to wallboard while nailing. Ridging See "Back-Blocking System", chapter -- SYSTEMS. See "Back-Blocking System", chapter -- SYSTEMS. Twisted Studs or Joists Burred Ends Ends of the boards become roughed up and can be felt as a ridge along the end of the board. The burr should be sanded off before board is erected. Cont'd. Framing members that are twisted in place presenting an angular nailing sur face which, when board is applied, pro jects an uneven sur face or offset along the entire joint. Warp ed dimension lumber may contribute to this type of deform ity. Align all twisted framing members be fore application. See "ImproperApplicaticn Procedure" and "Framing Require ments", chapter -- BOARD APPLICATION AND FINISHING. METAL PRODUCTS ACCESSORIES COLD WEATHER TIPS PERF-A-TAPE JOINT SYSTEM PRODUCTS All joint cements tenet to cold weather. Under atheist ttmtliiions, /tarticnlarly if cold mixing ieater is used, the cement mix should slant! at least M) minutes anti often much longer. Failure to recog nize and adhere to proper cold weather practices can lead to serious and costly complaints. BB026 1909 DO'S AMD DON'TS DO provide ventilation and adequate heat. (See chaplet--hoard application and finishing I. Temporary heat provided by salamanders, space heaters or unvented gas burners is often unsatisfactory. Insufficient venting to carry off fumes can cause staining of joint cement. Inadequate heat causes uneven drying, leading to bond failure, delayed shrinkage and joint discoloration. DO allow sufficient drying time between coats of cement and before decora tion. Under adverse job conditions 24 to 48 hours drying time is often insuffi cient. (Sec chapters--hoard apim.icaiion and finishing--field problems). DO plan work well ahead. Coordination between builder and dry wall con tractor is particularly essential during cold weather. DON'T add extra water to speed up or case mixing. Extra water causes ex cessive "watering down". Drying time is significantly slowed down, resulting in delayed shrinkage on the surface. DON'T store Perf-a-tape and Perf-a-tape cement in areas subject to dampness. DON'T use dirty or excessively cold water. Bond failure and delayed shrink age can occur. (Blow torch applied to side of water bucket will take chill off cold water.) Distal Products Accessories CONTENTS NO. 100 PERF-A-BEAD CORNER REINFORCEMENT............................. PAGE 42 NO. 101 DUR-A-BEAD CORNER REINFORCEMENT ........................... 42 NO. 300 PERF-A-TRIM METAL CASING............................................... 43 NO. 400 USG METAL TRIM................................................................. 44 NO. 200-A USG METALTRIM............................................................ 44 NO. 200-B USG METALTRIM............................................................ 45 NO. 200-C USG METAL TRIM............................................................ 45 NO. 500 USG SNAP ON TRIM........................................................... 46 41 METAL PRODUCTS ACCESSORIES No. 100 PERF-A-BEAD Corner Reinforcement Perf-a-head is a metal corner formed of electro-galvanized slecl with Perf-a-tape wings securely gripped by metal flanges. It is easily applied with Perf-a-iape ce ment (embedding) and designed to pro vide lasting corner protection in drywall construction. Pi-:rf-a-ueao forms an ex cellent corner for any outside angle, uncased opening, pilaster, beam or sollU. I'r.RF-A-m--ad is packaged 200 lin. feet | and 1000 lin. feet per carton. (6'8" or 8' '` lengths). (1 ) Apply Perf-a-tape cement on both sides of the corner over the entire area ' V;. to be covered by Perf-a-bead. (2) Hold- ; ing the Perf-a-bead in n vertical posi- . tion, place it tightly against the corner. ' (3) Completely scat the bead by run ning the thumb and forefingers up and down the outside nose of the corner. Apply pressure with the fingers to both of the paper flanges. (4) Embed the paper flanges by drawing the board knife down in each side of the corner. Excess cement thus removed under flanges later used in filling. Hold metal corner in place with one hand adjacent to the knife during embedding operation. (5) Using the metal corner angle as a screed, cover both the paper flanges with a smooth fill of cement 3" to 4" wide. Allow to dry 12 to 24 hours. (6) Apply second coat of cement (third coat if necessary) feathering edges 2" to 3" beyond preceding coat. Sand as required after each coat to remove iagged particles from metal angle. No. 101 DUR-A-BEAD Metal Corner Reinforcement Dur-a-bead is a metal corner reinforce ment of electro-galvanized steel, to pro vide lasting protection to outside angle comers in gypsum wallboard construc tion. Dur-a-bead is easily nailed to fram ing through Sheetrock Wallboard, and concealed with Perf-a-tape cement to a smooth finished corner. Lengths and Packaging--6'8", 8'--200' cartons and 1000' cartons. (1) Apply with gypsum wallboard nails spacing nails 3" apart. (2) Using metal bead as a screed, cover both flanges with Perf-a-tape cement about 3" to 4" wide. Allow 12 to 24 hours to dry. (Un der slow drying conditions, allow more time.) (3) Sand lightly if necessary-- apply second coat (third coat if neces sary) feathering edges 2" to 3'' beyond preceding coat. vjoo?_fs vno No. 300 PERF-A-TRIM Metal Casing An electro-galvanized channel with Perf-a-tape flange attached. It is de signed for use as a casing around door and under openings and at ceiling angles, and suitable for single layer or double wall gypsum wallboard con struction. Perf-a-trim is embedded with joint cement to produce a flush edge reinforcement. It is ready for painting. The Sheetrock is erected in the conventional manner, except that it is not nailed closer than one stud away from the area in which Perf-a-irim is to be installed. A space -3s" to W' wide is left between the edges of the jamb and the gypsum wallboard. This spacing adds a fluted effect to open ings and provides space for hardware or door bucks. The Perf-a-tape wing is held open, the metal flange of the Perf-a-tape is inserted between the frame and wallboard and pressed into place. The face of the trim is aligned parallel to, and Y" to Vi" away, from the face of the jamb. With, the wing still open the Sheetrock is nailed in position. The nail will penetrate the flange and hold it to the framing. The wing is then embedded with Plrf- \tape cement and the fill and finish coats are applied in the regular manner, using the edge of the trim as a screed to get a smooth, even finish. Perf-a-trim may be cut with either a hack saw or tin snips. Corners may be mitered by using a miter box. Lengths and Packaging--Is" and I 3" in 7' and 10' lengths. 43 METAL PROOUCrS ACCESSORIES No. 400 USG METAL TRIM A strong clcctro-galvanizcd metal channel for use as an edge protection and trim around door and window openings and as a moulding at ceiling angles in single and double layer gypsum wallboard construc * tion. USCi Metal Trim is economical, easy to install and provides a clean appearance often replacing old fashioned wood trim. USG Metal Trim is applied to the wall before the Sum rock goes up, by nailing i into the flaming through the long leg at approximately 8" intervals. USG Trim conies unpainted for use with plain Siieet- kock. and may be painted to harmonize with Striated Panel Sm.r.lROtK, and with Woodgrained Siiieirock. It is available in 7' and 10' lengths and in ->h"-Vi" thickness. The exposed face leg is Vi" wide; the con cealed or nailing leg is deep. 'Ihe metal trim is easily cut with a hack saw. For angular cuts a miter box may be used. USG Metal Trim is packaged 350 and 500 lin. ft. per carton. No. 200-A USG METAL TRIM No. 200-A USG Metal Trim is a channel type steel casing that provides maximum protection and a neat finished edge to gyp sum wallboard at window and door jambs. Apply Siieetrock Wallboard omitting nails at framing member where metal trim is to be installed. A space V" to Vi" wide is left between the edge of the wallboard and the face of the jamb. Slip metal trim over edge of wallboard and nail through nail holes provided in knurled flange into wallboard anti framing or jamb, using nail recommended for thickness of wallboard being applied. Space nails not more than 6" o c. Complete installation by applying Perfa-tape cement using nose of trim as a guide for determining proper thickness of cement. Apply cement in at least two coats, allow ing adequate drying between coats. For Vi" Sheetrock Wallboard only. BBQ26 1911 ft I -^ No. 200-B USG METAL TRIM No. 200-13 USG Metal Trim is similar in finished job appearance to the No. 200-A Metal Trim. By the elimination of a back flange, installation is sim plified. Metal trim is applied to the edge of the wallboard with the knurled fiange exposed and nailed not more than 6" o.c. No mitering is re quired; simply butt trim together at corners. Complete installation byapplying Perf-a-tape cement as for No. 200-A Trim Designed for : ' wallboard thickness only. s </ O <> No. 200-C USG METAL TRIM No. 200-C USG metal trim requires a slotted jamb for installation. Byinserting the open "v" flange into the slot of the jamb, this trim is adjust able for use with ?", Vi" and **" wallboard. Prior to installation, door and window jambs arc kerfed Is" wide and Vi" deep, the kerf being Va" back from face of jamb. Insert metal trim in kerf, with knurled flange over the face of the board. Nail as above. Design assures a clean tight joint without precision fitting. Apply Perf-a-i.ape cement as de scribed previously. i* 'i r l 45 -,V -V'v iSX'.iw*.' i iVt'/i-d}.ix&iii&jMbXiloijiiM 5 No. 500 USG SNAP-ON TRIM No. 500 USG Snap-On Trim is a modern metal trim for doors and windows and is designed to snap into position quickly and stay in place permanently. It reduces labor costs as much as 500?. The positive locking action holds the trim tight. No unsightly voids between trim and frame--no shrinkage to cause miters to open up. Resists damage and eliminates dust catching ledges. Also provides an excellent guiding edge for the application of wallpaper. It's bonderized ready for painting with no special preparations required. Snap-OnTrim goes on amazingly fast. The wood jambs are purchased slotted or kerfed from the millwork manufacturer or can be done on the job by using a 16 gauge planer type saw and making a slot not more than 1 j,;" wide the entire length of both sides and head jambs. Ibis slot or kerf, should be s/n" in depth and at approximately an 85 degree tingle toward the opening. No cutting is done. Kvcry package is complete and precut to size of door openings in following door sizes: 1-6, 2-0, 2-4, 2-6. 2-8. 3-0. 4-0, 5-0, 6-0 inclusive. Package contains 12-7 ft. pieces, left mitre, 12-7 ft. pieces right mitre. 12 head pieces cut to exact length, and 24 corner clips. A single package is enough for two sides of six doors. Instructions for installation tire contained in each package. Requires no special tools except a carpenter's hammer and nail punch. Systems BB026 1912 CONTENTS JOB LAMINATED SHEETR0CK GYPSUM WALLB0ARD-- PAGE THE DOUBLE WALL SYSTEM............................................................. 48 BACK BLOCKING SYSTEM...................................................................... 52 BACK BLOCKING CEILING JOINTS ............................................... 54 FLOATING--BACK BLOCKING END JOINTS--SIDEWALLS ................. 57 BACK BLOCKING HORIZONTAL SIDEWALL JOINTS...................... 60 RECOMMENDATIONS FOR CORRECTING A RIDGING CONDITION . 62 GOOD JOB PRACTICE TO MINIMIZE RIDGING....................................... 63 SHEETROCK WALLBOARD-TRUSSTEEL STUD PARTITION SYSTEM 63 NAILABLE STEEL STUD PARTITION SYSTEM.......................................73 SHEETROCK WALLB0ARD AND BAXB0RD BACKING-BOARD ACOUSTICAL TILE BASE....................................................................... 73 Vi" AND BAXBORD GYPSUM BACKING BOARD-ACOUSTICAL TILE BASE ............................................................................................73 DETAILS-ATTACHMENT SHEETROCK FIRECODE 60 WALLB0ARD AND %" BAXBORD FIRECODE 60 BACKING BOARD TO METAL NAILING CHANNELS ............................................................................ 74 PANEL SHEETROCK SYSTEM 75 At. JOB LAMINATED SHEETROCK GYPSUM WALLBOARD-THE DOUBLE WALL SYSTEM The basic double wall system consists of two layers of Vs" gypsum wallboard laminated together on the job. A base later of Baxiiord Gypsum Baching Board is nailed to the framing, and a l ace layer of .Siill t roc k Wallboard is adhesively applied to the base layer. Walls and eeilings so constructed offer greater strength, greater fire resistance ami greater resistance to sound trans mission. Moreover, they are highly resistant to cracking, easy to decorate; and they minimize the possibility of imperfections from face nails. Speedy erection cuts building time, permits earlier occupancy. Materials Needed BASE LAYER--Vs" B axrord Gypsum Baching Board in 4' x 8' panels specially designed for the double wall system. Both faces and the long round edges are encased in strong gray liner paper. This is not a finished product. The face side is not suitable for decoration. Baxhord Backing Board is economical, easy to handle, available plain or with aluminum foil on one surface to pro vide a vapor barrier and reflective insulation on exterior walls and top floor ceilings. (Regular 3/e" Sheetrock Wallboard may be used as an alternate to Baxbord for the base layer.) FACE LAYER--Vs" Tapered Edge Sheet rock--4' wide and up to 14' long. Several face layer alternates are available for walls: Vs" Panel Sheetrock 16" wide--7', 8', 9' and 10' long (depending on location)--Plain--Striated-- and Ranch Pine finishes; Vs" Woodgrained Sheet rock Wallboard--4' wide-- 7', 8', 9' and 10' long. NAILS--For base layer 4d cooler type, GWB-54 nails or power driven staples, 16 U. S. Standard gauge flattened galvanized wire, Vi" wide, 1" long, with divergent points. For temporary support of face layer nails of sufficient length to penetrate minimum %" into nailing member, temporary bracing, shoring or by double headed scaffold nails, stucco furring or 6d cooler type nails. ADHESIVE--Use Perf-a-tape Cement. Approximately 55 to 60 lbs. per 1000 sq. ft. of wall area. Note: The high ridges obtained bridge uneven areas and assure continuous bond. JOINT TREATMENT Perf-a-tape Joint System. For Tapered Edge Sheetrock 1000 sq. ft. wall area requires approximately 312'/2 tin. ft. of Perf-a-tape and 52 lbs. of Joint Cement. Spacing of Nailing Members Two layers of Vs" wallboard are the usual thicknesses used in the double wall system, however, greater thicknesses may be used to achieve additional value. The maximum spacings for nailing members is determined by the thickness of the base layer employed. Nailing member spacing should not exceed those shown in the following table: BASE LAYER THICKNESS LOCATION APPLICATION METHOD MAXIMUM SPACING OF NAILING MEMBERS %" Vs" y2- & %" Vt" &%'' Ceilings Sidewalls Sidewalls Ceilings Horizontal Horizontal or vertical Horizontal Horizontal or vertical 16" O.C. 24" O.C. 24" o.c. 24" o.c. NOTE: Where adhesive is not used between layers, limitations of nailing member spacing of single layer construction apply to both the base and face layers. 48 Framing BT3026 1919 Make a thorough check of the framing. Studs and joists must be in true alignment; bridging, fire stops, soil pipes, etc., must not protrude beyond framing. For best results heat should be provided to maintain a uniform temperature in the range of 45 'F. to 70 F. well in advance of and during board application, joint finishing and decorating. Ventilation should be provided to eliminate excessive moisture. Planning Two secrets of a good gypsum wallboard job tire the elimination of un necessary joints and locating joints which must occur at the least con spicuous locations. Careful advance planning of the job is important be cause the manner in which the face layers may he applied is largely de pendent upon the placement of the base layer panels, since joints between the two layers should he offset a minimum of 10". Generally, horizontal construction on sidewalls results in less lineal feet of joints. However, ceilings should be spanned with a single sheet if possible, regardless of the direction of the joists. The first step in good planning is to determine how the face layer board should be applied. Then, considering the location of the joints in the face layer, erect the base layer board so that the joints between the two layers shall be offset as described above. Application--Base Layer r* / f fy a % 4 n Cr: **Sv Nail BAXBORD Backing Board horizontally on ceiling first. Space nails a maximum of 7" o.c. End joints may occur on or between framing members and must be stag gered. On walls, apply BAXBORD vertically, long edge joints must occur on fram ing members. Space nails a maximum of 8" o.c. If staples are used, drive staple crown parallel to long dimension of framing member so that crown bears tightly against BAXBORD, but does not cut into paper. Spacing is the same as for nails } ! i i Application--Face Layer The face layer on ceilings may he applied either vertically or horizontally (refer to preceding paragraph 'Thinning"), depending on whichever results in least number of end joints. On walls, horizontal application is normally used. B8026 1914 DIRECTIONS FOR MIXING PERF-A-TAPE CEMENT (used as a laminating adhesive) c Mix Perf-a-tape Cement in clean metal container, using sturdy mixing paddle. (See Chapter--tools.) Use clean lukewarm (not hot) water for mixing up to 22 pirns of Witter to 25 lb. bag of cement. Pour all the Witter into a pail of suitable size, then pour all the cement to be mixed into the water. . Without wailing, stir vigorously for approximately Hi minutes; untie sure alt cement is uniformly damp. Allow' the mix to stand for 30 minutes. This is important. Stir vigorously for approximately 1 minute taking care to break down any lumps. The cement is now ready for use. Approximately 55 to 60 lbs. of cement are required for 1.000 sq. ft. of second or face layer of Sheeirock. Cut and fit face layer of 4' wide SHEETROCK Wallboard for the ceil ings. Then spread the PERF-A-TAPE cement adhesive uniformly over the entire back surface to the extreme edges of the board, using the ad hesive spreader blade. After the adhesive has been applied to the back surface, the face layer board *s erected. Wipe olf any ad hesive forced out along the edge. In horizontal application, face layer end joints may occur on or between framing members. When the end joints occur between framing members, the back block ing surface alignment procedure should be followed, using wood supporting strips to assure align ment. The face layer may be tempo rarily held in place with nails of sufficient length to penetrate a minimum of -Id" into the nailing member, by temporary bracing, shoring or by means of double Following application of the upper boards, erect face layer of SHEETROCK Wallboard on tower walls Upper and lower boards should be loosely butted together. Note how the PERF- A-TAPE cement adhesive has been ap plied to the back surface of the board headed scaffold nails to which large fiber or wood washers are applied, stucco furring nails or (id cooler type nails hacked up by liwnoitD or Sitiim hock blocks (used as washer). Temporary nailing or bracing should provide support every Id" to 24". After the laminating adhesive has thoroughly dried (usually 24 to 48 hours) the temporary nails should be pulled or the double headed scaffold nails, the nails supported by washers, and the temporary shoring or bracing, should be removed. Where double headed or furring nails have been used without a washer, a thin wood block should be placed under claw hammer head when nails are pulled to prevent damage to face layer surface. For best results dimple holes left by temporary nails with crown head hammer directly over hole to facilitate concealment with Perf-a-tape cement during joint treatment application. 50 Only the overlapping panel of Baxbord is nailed to the corner framing, securing both boards into the corner. The " SHFnrrock face layer is not nailed. A ''floating" type of corner results after reinforcement by application of the Perf-a-tape Joint System. i Only ihe face layer of Smi.i irock not the Baxhord--is nailed to the framing. When naii-on corner re inforcement is applied, use tem porary nails at locations shown: otherwise use permanent nails penetrating framing approximate!) U" and countersink as shown or conceal by the corner reinforce ment. Finishing Nail heads are spotted with Pf.rta-i ape Cement and joints are treated with Perf-a-tapc Joint System according to directions. (See chapter board application and finishing--"Joint and Corner Treatment" and chapter technical data -- "Paint and Finishing Guide*'). Handy, Easy-To-Make Spreader Blade Metal blades are recommended. With blades made of other mate rials the cement tends to accumu late and dry in the notches, pre senting proper spreading action. Stainless or galsam/ed steel makes the best spreader. Ii should h.oc the approximate stillness of a plaster-trowel blade. Ihe blade should be kept reason ibis Jean at all times. A 5" \ Id" blade is most eileetoe lor spreading ce ment. As shown .those, the recom mended spacing of notches is lli", with notches >. i" deep, taper ing out to 5 16" in width at edge of tool. Note that notches base a rounded, i other thin a sharp apex. (See chapter loots). USG BACK BLOCKING SYSTEM* Introduction Gypsum wallboard diywall construction has made rapid progress in the last few years, Gtpsum wall hoard is fast heeoming the standard wall and ceiling material for residential construction. The proliciency of the mechanics doing joint finishing win k has been highly instrumental in the growth and public acceptance. 1 lie skill with which joints are now being concealed highlights certain basic problems which several years ago were not noticed or recognized. We refer to the difficulty of properly concealing end and edge joints under all practical working conditions. We refer specifically to a deformity at the joint called "ridging" or "beading.'' The construction procedure herein described was developed by the United States Gypsum Company as a means of minimizing "ridging" deformities. The procedure is simple and effective. It has been tried and proven. The following has been prepared in order to give you general information on the subject of ridging and the steps which may be taken to minimize it. Ridging Defined "Ridging" or "beading" is a joint deformity which appears, as the name im plies, as a continuous ridge or head along the length of the joints. It is often confused with other types of deformities, principally a starved joint, or joints, which occur on twisted studs. In general, ridging can be diagnosed reasonably accurately by its uniform fine ridge-like pattern along the exact center of joint. Characteristics Unlike other defects which are apparent almost immediately, ridging gen erally develops and becomes apparent after the joint finishing work has been completed. Tin's period of time may be from a few hours up to several months before it first becomes apparent depending upon factors described later on. Many drywall contractors, general contractors and builders are of the opinion that ridging is a relatively new problem--that years ago they were never bothered by such a condition. Actually, we first observed ridging in 1940. We know that this condition has always existed and we have observed that ridging does not become a serious problem until a certain skill in joint finishing is attained. Ridging in the past was generally not specifically noticed because of the many other imperfections due to relatively poor workmanship. Today, with large numbers of drywall contractors doing extremely high quality work and with a more critical market, ridging has become a problem requiring recognition. It is often felt that ridging occurs only on ceilings. Actually, it occurs on side walls with the same frequency as on ceilings. However, it is much more apparent on ceilings than side walls because the ceiling is the largest unbroken surface in the room and the angle of view and light conditions are more favorable for the detection of blemishes; however there is usually a need for minimizing ridging of horizontal sidewall joints. Conditions Causing Ridging We know, not only by observation but also by laboratory tests, (hat not all jobs ridge to the same degree. The degree to which they will ridge depends upon a combination of factors. We know definitely that the possibility of ridging is greater on jobs when the joints are taped and finished during cold, damp or high humidity periods. We also know that in the case of two joints --one finished with a high crown or heavy fill and 14" wide, and one finished flat and 8" wide--that under the same climatic conditions during taping and drying the flat and narrow type of joint concealment will ridge to a lesser degree. Joints finished with a high crown during damp, cold climatic condi tions or under conditions of high humidity are almost certain to ridge to an objectionable degree, whereas joints finished fiat and narrow under ideal drying conditions seldom ridge to a degree where it is visible to the eye under 'The Back Blocking System herein described is covered by U S. Patent No. 2736929 Bj3026 1915 normal lighting conditions. These two combinations represent the extremes of causes and results. There are many in-between combinations which mat' cause objectional ridging. Ridging is not a result of a quality defect. The explanation as to exactly what causes the ridges to develop is com plicated and difficult .to explain with ut a lengthy dissertation on the subject. Since we feel that this information has little practical value, it is not covered. Prior to World War II, construction activity was generally stopped dur ing the winter months or periods of inclement weather. However, since that time, and due to an unprecedented demand for homes, residential construction is carried on during all months of the year. To maintain the year-around building program, builders have found ways and means of protecting various other components of the building from the hazards of extreme climatic conditions. These measures are costly but are the penalty for building during adverse weather conditions. The costs are reflected in the price of the house and the buying public has accepted the penalty. Building under adverse conditions and at an increased tempo has had its effect upon the overall quality of joint finishing, and particularly wiih respect to the more frequent occurrence of ridging. This fact, ccmhincd with the increased proficiency of the joint finisher and a more critical market, dictates that steps must be taken to minimize the danger of ridging in gypsum wallboard jobs. Recommendations for Minimizing Ridging The United States Gypsum Company back blocking system was developed to minimize ridging, its continuous use over a period of years by many drywall contractors and builders is conclusive proof of its effectiveness, and likewise it is also proof that the cost is not prohibitive. We urge all drywall contractors, builders and general contractors to adopt this system as a standard for all single layer wallboard construction. We recommend back blocking ail ceiling joints along tapered edges and floating and back blocking all end joints, side walls, and ceilings. End joints, side walls and ceilings may be tapered as shown at the discretion of the contractor or applicator. On almost every job there are exceptionally critical wall areas where joint ridging would be noticeable, such as large unbroken surfaces subject to harsh natural or artificial side lighting which magnifies any surface variation. Noticeable ridging in these areas can be minimized by back blocking only the one side of the partition that is most critical in appearance. In cold weather when back blocking is used the building should be heated during the application to maintain a uniform temperature range of 45 to 70F and ventilation should be provided to eliminate excessive moisture. Following is a pictorial presentation of the procedure for floating, backblocking and tapering end joints and back blocking cJge joints. 53 BACK BLOCKING CEILING JOINTS 1. Tools and Materials Needed-- Hacking blocks arc cut from scrap wallhoard. Use /" or i" thick hacking blocks for Ir" wall or ceiling finish; Vz" or 5h" thick blocks for -Vs" wall and ceiling finish--use face side of blocks for lamination if foil back material is used. They should be approximately 10" wide and of sullicicnt length to fit loosely between the joist spaces. T hey need not be ac curately cut. The adhesive is Pi ki-\-iAi'i: (embedding) Ce ment or All Purpose Ready- FIG. 1 Mixed Pt.K/-A-1ai-r; Cement mixed to a consistency which permits easy spreading and leaves a standing ribbon of cement. The spreader as shown can be made locally. The notches should be 5/16" wide by Vi" deep and spaced approximately \Vi" o.c. ' 2. Applying Ceiling--When the ' back blocking is used the gyp sum wallhoard must be applied with the long edges at right angles to the joints as shown in the picture. This procedure facilitates the placement of the blocks along the full length of the edge and ends of the board. The board in figure 2 and following sequence of pictures will be applied in a manner illustrating floating end joints. Additional advantages are gained by floating the end FIG. 2 joints, in that the difficulty of forming a good joint over a twisted stud or joist is eliminated. As described later, the buck blocked, floated end joint may be tapered to facilitate easier joint treatment. FIG. 3 3. Spreading Adhesive -- The adhesive is spread on the blocks as shown. T he adhesive is ap plied so that the ridges will be perpendicular to the joint. It is important that the ridges are well formed and are a mini mum of 14" high before in stallation. The cement should be spread on the blocks just before the blocks are to be in stalled. Vibration due to nail ing of face boards will cause blocks to settle and the adhesive to spread. FIG. 4 BB026 4. Positioning Blocks for Floating End Joints--Note a different procedure is used in blocking ceiling end joints. Blocks are placed prior to erec tion of succeeding board. The same size blocks, xxhich are used for the edges, are used for the ends, thus eliminating the need for different sized Mocks. Blocks and cement arc gener ally cut and mixed respectively in advance of the erection of the board. The general pro cedure on the iob is for one man to complete nailing the board while the other applies cement to the blocks and placethem. FIG. 5 5. Continuing Board Erection -- Immediately after all the blocks are in place the next board, which has been pre viously cut, is erected. To pre vent the cement from drying and a resultant loss of bond al ways apply cement on blocks just prior to erection of tbe wallhoard. The ends are loosely butted. Care should be exer cised to avoid tight fitting ends. On the other hand they should not be spaced apart. The ends of the boards should be free to move independently of one an other. 6. Positioning Blocks for Edge Joints -- After the next board has been cut to the proper size, the blocks along the tapered edge are positioned. Slightly over half of the width of the block is resting on the ceiling board. Note that in all cases the cement ridges are perpen dicular to the joint. The partner of the mechanic placing the blocks has finished nailing and is getting the next two gypsum wallboards cut to size. FIG. 6 55 FIG. 7 7. Continuing Board Erection -- The mechanic is finishing nailing the first board of the second course in place. His partner is spreading cement on the blocks for the end joint. The next board which has been cut to size, will be positioned and nailed as soon as the end joint is blocked. Mechanics should always apply all face boards required to conceal blocks in position before going to lunch or taking normal job breaks. Nails, nail spacings and nailing practices arc the same as for the conventional single layer gypsum wallboard con struction. 8. Tapering Ceiling End Joints -- End joint "A" should be tapered as soon as board 1, 2 and 3 are in position. It is nec essary to have board 3 in posi tion before tapering since the wood strip over the end joint extends beyond the joint and on to the surface of board 3. The procedure for tapering end joints is the same as shown in steps 7 and 8. Do not depress ends of board more than Va". The wood tapering strips are FIG. 3/s" x f'/i" oak flooring or any good quality wood strips. The three shorter strips are approximately 4" to 6" longer than the distance be tween nailing members (22" long for framing spaced 16" c. to c.), pre-drilled at each end to accept a 2Vi" double head scaffold nail. Pre-drill nail holes in wood strips to conform with framing spacing. The shorter strips are first loosely nailed to the Sheet rock surface. The longer strip, which is approxi mately 54" long, is then centered over the joint and underneath the horizontal strips as shown. (In lieu of wood tapering strips, supporting strips of wallboard may be used as described in step 14 merely to assure alignment of adjoining ends.) I BRACES IN PLACE 7. BRACES REMOVED FIG. 8A FIG. 8 A 8-A. Cross Section of Tapered Butt Joint--Here is a cross sec tion showing tapering and back blocking of a floated end joint. Note the wood strip in the top drawing, depressing the ends of the boards. When this strip is removed, a tapered formation remains as shown in the bottom drawing. Taping should not be started until 24 hours' drying time has elapsed following the installation of the back block ing System. B3026 1917 9. Back Blocking End Joints Which are Centered on Joists --As shown above, end joints may be successfully hack blockej without floating the joint between the joists. !n this method the ends of the hoarJ are nailed to the joist in the conventional manner. Then the back blocking strip, with adhe sive applied, is placed on top of the ceiling board as shown in the sketch. Fic, 9 This system is effective in minimizing ridging. However, it does not haw the advantage of compensating lot twisted joists as dtws the float ing nicthoil. FLOATING --BACK BLOCKING END JOINTS -- SIDE WALLS 10. Stopping Strips for Back Blocking -- Strips of gypsum wallboard approximately 2" wide and 52" long arc tacked in place along the side of the stud with a minimum of three nails and set back from the sur face of the stud the thickness of the back blocking which is to be used. The purpose of the stopping strip is to hold the back blocking in position until the adhesive has bonded the blocking and surface boards to gether. 11. Side Wall Blocks -- The side wall hack blocking is cut .slightly less than the width of the stud space and approxi mately 4" longer than the space to be blocked, allowing the block to extend behind the up per course of board as shown. Note the high ridges of l'i hi a-1'xpe Cement or All I'uipose Ready-Mixed Pi nr-1\iu: Ce ment applied so as to he at right angles to the vertical end joint. (Ceiling end joints tire blocked in a slightly diUVrcnt manner as shown in I'ig. 4 ) 57 12. Positioning Side Wall Blocks--The block is in posi tion and is being nailed to the stud from the lace as shown above. Three nails along each edge arc sufficient. The block is held in the plane of the wall as formed by the studs and by the scabs along the sides of the studs as shown in Figure No. 10. Always make certain that the blocking is flush or slightly back of the nailing face of the studs--never allow it to pro trude. 13. Applying Gypsum Wallboard -- The next step is to position and nail one wallboard panel in place. Note the end of this board occurs approximately mid-way between the supports and over the blocking. Also note that the end joints between the upper and lower courses of panels are staggered. As the gypsum wallboard is nailed along the stud, the end of the board is forced into the cement on the blocking. 14. Applying Gypsum Wallboard Continued -- The adja cent panel is put into place, loosely butted to the preceding one and nailed to the studs bringing the face board into contact with the cement. To as sure alignment of the adjoining ends of the wallboard, 6" wide strips of wallboard are used in lieu of the oak flooring strips shown in Figure 15. After 24 hours the strips are removed and the joint is back blocked ready for taping. Joints treated in this manner will require the usual finishing technique of crowning necessary for end joints. \ k - Bi?02 s l9ls 15. Tapering End Joints--In lieu of using strips of wallboard to maintain alignment as described in Figure 14, the end joints may be tapered by fol lowing the procedure pictured on the left. The strips are pieces of 1'h" x 1" oak floor ing. The horizontal strips are first loosely nailed, with double headed nails, to the undetlying supports. The vertical piece, which is approximately 54" long, is then centered over the joint and underneath the hori zontal strips as shown. Ceiling joints are tapered in the same manner. FIG. 15 16. Tapering End Joints Con tinued--After the vertical strip is in position and centered over the joint, the double headed nails arc driven in light caus ing an inward pressure on the vertical strip. This pressure aligns and depresses the adjoin ing ends of the board. After 24 hours when the strips are re moved. the end joints will spring outward, but a slight concave depression will remain. The depression is usually sufiicient to permit concealing and finishing the joint flat without the usual crowning. FIG. 16 MllWWHPWf'WM! 59 immm BACK BLOCKING HORIZONTAL SIDEWALL JOINTS --BOTH SIDES OF PARTITION FIG. 17 17. Stopping Strips for Hori zontal Sidewall Back Blocking --When both sides of a critical wall arc to be back blocked, two gypsum wallboard stopping strips cut from scrap Sheetrock arc tacked in place at the 4' level of the joint along the side of each stud. Two nails per strip are sufficient. They arc set back from the surface of the stud the thickness of the back blocking which is to be used. The thickness of the back block ing used, therefore, governs the width of the stopping strips (approximately 2'A" wide for 'A" Sheetrock). Stopping strips arc approximately 10" long. 19^ 3B026 18. Positioning Sidewall Blocks --The stopping strips hold the back blocking in the plane of the wall as formed by the studs and the stopping strips along the sides of the studs. The blocks arc toe nailed to the stud from the face: The blocks arc cut slightly less than the width of the stud space and approximately 10" wide. When a sullicicnt number of back blocking strips have been tacked in place, Pere-a-tape Cement or All Purpose Ready Mixed Cement may he spread on the blocks already in position, Im mediately following the applica tion of the cement the top and bottom sheets of Sheet rock Wallboard should be nailed in place in the conventional man ner on one side of the wall. 19. Spreading Adhesive on Blocks--To complete the back blocking installation of both sides of a critical wall the same procedure described in Figure 18 is followed on the opposite side of the wall. Always make certain that the back blocking is flush or slightly back of the nailing face of the studs--never allow it to protrude beyond the stud face. Perf-x-tape Cement or All Purpose Ready Mixed Cement is spread on the blocks after a sufficient number of blocks are in place. Note the high ridges of the cement applied so as to be at right angles to the horizontal joint formed by the Sitr.F.FROCK soon to be applied. 61 60 T 20. Applying Gypsum Wallboard -- Hoiizontal application of the top sheet of Snr:t.ihoc k Wallboard in the conventional manner follows immediately alter spreading ad hesive on the blocks. I he adjacent and bottom panel is then put in place. The tapered edge joint so formed is now back blocked. After 24-4X hours drying time, joints should be Heated in the normal man ncr. FIG. 20 BACK BLOCKING CRITICAL SIDE OF PARTITION On almost every job there are exceptionally critical wall areas where joint ridging would be noticeable, such as large unbroken surfaces subject to harsh natural or artificial side lighting which magnifies any surface variation. Noticeable ridging in these areas can be minimised by back blocking only the one side of the partition that is most critical in appearance. 21. Block Installation on Fin ished-One Side Partition--Where back blocking is desired ONLY ON ONE SIDE of a critical wall, back blocking strips are adhesively applied to the back side of the horizontal joint formed after the Siileirock has been applied to the framing members. The blocks are merely tacked into place by nail ing into the stud to provide brac ing while the cement dries. The gypsum wallboard stopping strips me not nm'iwm'. fig. 21 RECOMMENDATIONS FOR CORRECTING A RIDGING CONDITION When ridging occurs oil joints which hove not hern inn k blocked take fol lowing sle/>\: 1. Let ridge develop fully bcfoic repair is undertaken. Usually six months is xullieient time. It should he repaired under hot and dry conditions. 2. Sand the ridge down to the reinforcing tape without cutting through the tape, bill the concave areas on either side of the ridge with a light fill of thick mix cement. After this is dry, float a very thin film of cement over the entire area. 3. Examine the area with stiong side lighting to make certain that the ridge has been concealed. If not, use additional coals of cement. Redecorate. BI3025 1920 Joint ridging is almost never encountered when job laminated Double Wall System with Sheetrock Wallboard is used. If cost is a consideration, the USG Double Wall System can be used on ceilings only where joint ridging is generally most noticeable. Recognizing that not all jobs can afford the additional cost of the Double Wall System, it is suggested that consideration be given to the back blocking system. THE FOLLOWING GOOD JOB PRACTICES WILL TEND TO MINIMIZE RIDGING ON JOBS WHERE THE PRECEDING DESCRIBED METHODS ARE NOT USED 1. Houses should be heated at least two days before joint treatment is started. Temperature of 70 F should be maintained day and night until the bouse is occupied. Ventilation should be provided to eliminate excessive moisture. 2. Cement for all coats should be used at as heaviest workable consistency. 3. Emhed the tape and immediately follow up with a covering coat. 4. At least two days' drying time should be allowed between the first and second coat of cement. 5. The fill and finish coats over tapered edge or butt joints should be held to the minimum width required to produce a smooth finished joint. 6. At least one day's drying time should be allowed between the second and third coats of cement. 7. At least four days' drying time should be allowed before decorating 8. Use of All Purpose Ready Mixed Perf-a-t.vee Cement in itself will tend to minimize ridging. SHEETROCK WALLBOARD-TRUSSTEEL STUD PARTITION SYSTEM DESCRIPTION AND ADVANTAGES The Sheetrock Wallboard-TRUSSTEEL Stud Partition System is a non-load bearing partition consisting of lightweight, open-web steel studs faced on each side with a base layer of -Ik". 2` wide by S' long Bsmioro Gypsum Backing Board clipped to the studs and surfaced with a layer of -'C Sun trock Gypsum Wallboard 16" wide or 4' wide adhesively bonded to the base layer. Either metal or wood floor and ceiling runners may be used, depending on code regulations or insurance requirements. Savings and adaptability are inherent in the Sheetrock-Trusstrr.L Partition System. Along with the usual drywall advantages of speed and cleanliness, the system offers: Open-Web Stud Construction--The open-web stud design simplifies installation of electrical conduit and plumbing pipes--generally no cutting of stud is required. Fire Resistant--Consists of incombustible steel studs and attachment accessories plus Sheetrock Gypsum Wallboard facings. Lightweight--The finished partition will weigh approximately 7 IK per square foot--less than other steel stud partitions with ' ; " or 7*' thick facing materials. Adaptable--May be used in new construction or for modernizing old buildings--for commercial, industrial or residential work. Dating mod ernization, the normal work can progress with a minimum oi mess and disturbance. Economical--Because A. Low Material Cost B. Speedy Election C. Dry Wall Assembly limitations of use 1. I ho Siii:i: i ruck \Vallbonrd-Titus.SM-:i:i Stud Partition System wax designed for use only as a non-hearing partition. 2. Maximum stud spacing 24" ox. 3. Should not be used where normally exposed to excessive moisture or humidity. 4. Sun: iroi'K facings shall be adequately protected against welting or mois ture absorption. TECHNICAL DATA Stud Width Maximum Stud spacing Maximum partition height Finished Wall Thickness Snap in track Snap-in and shoes track only 1'h" 3vr 4" 6" 24" o.c. 24" o.c. 24" o.c. 24" o.c. 10' 4%*" 4V 12' 5V 5 3/14" 14' 6 5%" 14' 8'/"(l) Not applicable (1) 6" Snap-in track not available--for 6" wide studs use 6" Standard track and shoes. Sound transmission Rating--Approximately 45 db. (studs spaced 16" o.c.). Test conducted at Riverbank Acoutical Laboratories June, 1954. Fire Resistance Rating--45 minutes, face layer %" SHEETROCK Wallboard. 1 hr., face layer Vz" SHEETROCK FIRECODE 45. (Studs spaced 16" o.c.). Where fire rating >s required use stud shoes at ceiling runner. Nationally recognized Fire Testing Labora tory--name and special details on request. See chart page 92. Approximate Weight--7 lbs. per square foot. CUTAWAY PERSPECTIVE COMPONENT PARTS BB026 1921 TRUSSTEEL Stud Snap-In Runner Track Width--for 2'A", 3'A", and 4" studs. For 6" stud width, use standard 6" runner track and stud shoes at floor and ceiling. Lengths--8' only. Packaged--10 pieces per bundle. TRUSSTEEL Studs Width--2Vi", 3Vi", 4" and 6". Lengths--7' to 14' in 3" increments. Packaged--10 pieces per bundle. Shld Shoes ', Length--is . Packaged--500 per carton. Usage--See Note. NOTE: (Use at ceiling only). Where fire rating is not required and/or ceiling height variation permits use of studs pre-cut to length, stud shoes may be elim. inated. Where wood runners are used, use shoes as shown in details. TRUS-LOK TL-1 Clip Packaged--500 pieces per carton. Usage--Approximately 1 per lineal foot of stud less 2 for each stud. TL-Drive-ln Starter Clip Packaged--500 per carton. Usage--Approximately 1 per lineal foot of runner track. BRIDJOINT B-l Clip Packaged--500 pieces per carton. Usage--Approximately 2 per piece of Baxbord less 1 for each 2 lineal feet of partition. BAXBORD Backing Board Size--Ye" x 2' x 8'-- Round edge. Packaged--2 pieces per bundle. SHEETROCK Gypsum Wallboard Sizes--Vs" x 4' x Lengths 6' to 14' or 16" wide Panel Sheetrock in 7', 8', 9' or 10' lengths. Edge--Tapered or beveled for 4' wide Sheetrock, round edge for 16" wide Panel Sheetrock. Packaged--2 pieces per bundle (4' width). 4 pieces per bundle (16" width). Adhesive Perf-a-tape Joint Cement. ERECTION DETAILS Snap-in runner tracks arc aligned and anchored securely to concrete ceiling and floor slabs with suitable fasteners (equivalent to power driven studs). Stud locations are marked on ceiling. Studs .spaced not more than 24" o.c. should be snapped in place vertically in the notches provided in the runner track. Each stud should be secured to runner track with two attachment shoes at top if required (see "note" component parts) by inserting the wing of the shoe clip in opening pro vided in snap-in ceiling runner. Snap stud into stud shoe, then atdch second stud slice as [lie mechanic is doing in piclurc No I Said shoes are anchored to studs hy crimping flanges around stud flanges as shown in picture No. 2. Studs need not he accurately nlaeed nor perfectly plumb. STUDS-- To be located approximately 2" from all door buck jambs, abut ting partitions or other construc tion. Studs supporting steel door frames shall be secured to ceiling runner track with stud shoes. With steel bucks, an additional anchor age stud is required at each jamb. Anchor studs adjacent to door bucks to the jamb anchors (see details), see page 72. All corners should be framed with one stud approximately 2" from the exter nal corner and one stud approxi mately 2" from the internal angle of each of the meeting partitions. BASE LAYER-- Loosely position the TL-Drive-in Starter Clips spaced not more than 24" o.c. with the long leg between the floor runner and floor and lo cated near the point at which the runner is anchored to the floor. The first course of Baxbord Gyp sum Backing Board is applied, starting at the floor level and working upward with the long (8') edge parallel to the floor. The Baxbord is inserted between the floor runner and the upstanding leg of the TL-Drive-in Starter Clip and held in position against the stud at the top by the TL-1 Clip hooked around each stud crossed as shown in figure 4. The TL-Drive-in Starter Clips arc then driven home to hold the Baxbord securely against the runner or stud shoes when used. 3 Setting TL-Drive-in Starter Clips against BAXBORD. BASE LAYER Cont.-- The mechanic is positioning a TL-I Clip as shown in fig. 4 to hold the Baxbord Backing Board at its top edge. Note the downward angle of the loop of the clip which engages the 'I trusst ut:L Stud (see arrow). The Baxbord is secured at the bot tom between upright wings of the clip which engage the stud. 66 Securing BAXBORD to stud with TL-1 Clip. The Brid.ioint B-l Clip shown in fig. 5 in the mechanic's hand is used to anchor adjoining ends of Baxbord to one another and to adjoining edges. The prongs of the clip arc flared on both sides for easy entry. Baxbord end joints are staggered in ad jacent courses and always oc cur between studs. Succeeding courses of Baxbord Backing Board must be attached by in serting the bottom edge into the top portion of the TL-I Clip of preceding course and secur ing it at the top edge as pre viously described. BB026 l-927- Anchoring adjoining ends of BAXBORD with B-i Clip. The last or top course of Bax bord should be cut to the prop er width. The bottom edge se cured to the studs as previously described. Fig. 6 shows the top edge of Baxbord solidly held in contact with the stud shoes, if required, or runner at the ceil ing line by TL-Drive-in Starter Clips spaced a maximum of 24" o.c. and located adjacent to the runner anchors. One or two such clips are placed adjacent to end joints. FACE LAYER-- The facing units should be cut to full floor to ceiling height lengths less Vi". Full width boards are to be used wherever possible. Boards with broken or damaged edges should not be used. Adhesive mixed in accord ance with the manufacturer's directions should be applied to the back side of the Sueetrock facing unit in ribbons of cement spaced not more than 1" apart and approximately IVI" to 2" from each edge, end and cut outs of doors (fig. 7). The ribbons of cement must be ap proximately Vi" wide at the base and high. 6 Placing a TL-Drive-in Starter Clip at ceiling to anchor BAXBORD at ceiling. rv\ ~V * 1 7 Spreading adhesive on back of SHEETROCK. 67 THE SPREADER-- I he spreader Made may be made on tlie ioh or at a sheet metal shop. I he spreader blade is 7" across the top. 4'' aeioss the bottom and 1" high. Face slants approximately 17 off of vertical. Angle of wing <iii nine is approximately 45r otr of vertical. The notch in the spreader is lit" wide at the base and high. -7" A m ,V n DETAILS i ^ PERF A-BEAD OR DUR A-BEAD 7" ; Jj` INTERIOR CORNER BB026 192^ .( is Immediately after applying the ce ment. each board shall be placed vertically against the Baxiiord base layer and held in position at the top by T L-Drive-in Starter Clips (sec arrow), fig. 9, until adhesive has set. The clips may then be re moved or driven tight against the Baxiioki). The face layer of Siieetrock Wallboard is held in position by mechanical attachment or brac ing until the adhesive bonds the two units together. Attachment may be accomplished by face nail ing at a 45 tingle, bracing from the floor or using a Paslode Air lacker (air actuated) No. PTL-75 and No. P-3375--Va " staples or equivalent (fig. 10). Staples shall be driven with the heads slightly below (lie Siu.i crock face paper surface and shall remain in place and be covered with Pi.iu-a-tapi. Cement. The number and spacing of temporary attachments is gov erned by job conditions; however, usually temporary attachment is required only at edges and center of the wallboard. Succeeding units are likewise positioned with ver tical edges abutting the surface flush with the ones previously erected Spreader Blade Temporary attachment by stapling. .Hi FURRED WALL !U !*i II I It Ij t* PLAN SEC. THRU OUTLET BOX PARTITION TERMINAL DETAIL It is not necessary to nail on Dlr-a-bead corner reinforcement. Apple Perf-a-tape cement (embedding type only) to corner and seat Di r-\-re\1) firmly into cement. Allow to dry and finish corner in normal manner with Perf-a-tape cement. BF3026 1924 SPECIFICATIONS COVERING THE USE OF WOOD FLOOR AND CEILING RUNNERS ARE ESSENTIALLY THE SAME AS FOR STEEL RUNNER TRACK EXCEPT: A. Pointed Trussteel Stud shoe clips are used and are secured to the wood floor or ceiling runners by driving the points into the wood. B. The TL-Drive-in Starter Clip is not required. Bwroro Backing Board is secured in position by nailing through the Bsxbord into the wood floor and ceiling runners. Likewise, the facing unit may be held in position In nails driven through the facing unit. Bvxrord and into the wood ceiling runner. C. Optional use of the Snap-In Runner Track is suggested when wood floor and ceiling runners are used. The Snap-In Runner Track is anchored to the wood runner. Studs are secured by snapping in place vertically in the notches provided in the Snap-In Runner Track. Stud shoes are not required at floor or ceiling. Wood runners tire milted to runner truck width dimension. 70 71 TRUSSTEEL STUD DIMENS, l ly,6" MAX DETAILS -- METAL DOOR FRAMES OtU/ii CO 3 o i ISOMETRIC OF 16 Gfl. ANCHOR CLIP \Vt : r.f<T'. BB026 1925 nailable steel stud partition system (SINGLE LAYER CONSTRUCTION) Detailed information concerning the fire resistance raiings for this type construction and specific construclion dtila pertaining to this system is covered in chapter--technical data--"Fire Resistance Raiings for Sun ihock Wallboard". Sec consiruciion reference (HI. SHEETROCK WALLBOARD AND EAXBORD BACKING BOARD ACOUSTICAL TILE BASE ANCHOR CUP FLOOR ANCHOR (2 POWERACTUATED STUD ATTACH MENTS. OR EQUAL, REQUIRED) 'k"Sheetrock Firecode 60 Wallboard and 5" Bvxhord Fnu.cnnr (>() Hacking Board is recommended as a base for acoustical tile (adhesive or screw-on application). These products provide an extra strong rigid base for acoustical tile on steel joist concrete floor and ceiling construction when attached to nail-on channels. (Construction data and application recommen dations relative to steel construction on ceilings is covered in chapter-- technical data--see "Fire Resistance Ratings for Sheet roc k Wallboard" reference (K). Installation drawings of the above mentioned system described in the "technical data" chapter are shown on the following pages. These products are also recommended for acoustical back-up on wood frame construction where extra fire resistance and rigidity are desired, hut a one-hour rating is not required. V2" BAXBORD GYPSUM BACKING BOARD V2" Baxbord Gypsum Backing Board is also recommended for a ceiling back-up material for acoustical tile (adhesive or screw-on application). Baxbord is always applied with long edges at right angles to framing mem bers. Nailing to wood framing is accomplished with GW B-54 or 5d cooler type nails. Nail spacing should be 1" o.c. for joists spaced 16" o.c. Joists spaced 24" o.c. require nail spacing of 5" o.c. ` 2" Baxbord may be nailed to metal supporting members such as Jackson. Pomeroy or similar bars and various nailable steel joists (consult Sweet's Catalog'. y8" BAXBORD GYPSUM BACKING BOARD (4' WIDE) Vk" Baxbord Gypsum Backing Board (4' Wide) may be used as a base for adhesive application of acoustical tile on ceilings when nailed pei pcndiculai to wood joists 16" o.c. maximum. Use GW B-54 or 4d cooler type nails. 7" o.c. SECTION THRU HEAD (SEE JAMB SEC. FOR DIMENS.) 72 73 DETAILS--ATTACHMENT OF %" SHEETROCK FIRECODE 60 WALLBOARD AND %" BAXBORD FIRECODE 60 BACKING BOARD TO METAL NAILING CHANNELS (ALTERNATE METHODS). SECTION THROUGH END JOINT--BACK BLOCKING METHOD OF SUPPORT %" FIRECODE 60 SHEETROCK OR BAXBORD REINFORCING STRIP -- 8" WIDF PERFA-TAPE CEMENT (COMBEO IN RIDGES ACROSS END JOINT) END JOINT (LOCATED MIDWAY BETWECN FURRING) SECTION THROUGH END JOINT -- DOUBLE NAILING CHANNEL METHOD OF SUPPORT SECTION THROUGH 7/a" NAILING CHANNEL -- SPACED 16" O.C. NO. 18 W & M GA. GALV. WIRE SADDLE TIE AT EACH JOIST ANNULAR TYPE NAILS, l/4" LONG, NO. 11 W & M GA. Vi*" HEAD. SPACED 6" O.C. SECTION THROUGH -- /4" COLD ROLLED CHANNEL SPACED 16" O.C. JOIST BOTTOM CHORD 74 BI3026 192(3 PANEL SHEETROCK WALLBOARD SYSTEM Panel Sheet rock is excellent for surfacing walls in new construction and remodeling. It is availahlc in panels thick. 16" wide: and may he ordeted (depending on geographic location I in 7'. 8'. 9' and 10' lengths. Plain Panel--The face side is surfaced with a highly calendered maniia paper suitable for any decoration. Ranch Pine--The face side is surfaced with a high quality prcdecniaicd paper to simulate the color and graining of real wood. Striated--The face side is surfaced with a durable plastic in a neutral tone, forming a pattern of raised lengthwise ridges. NAILING DIRECT TO WOOD FRAMING The vertical edges must be reasonably well centered on the underlying framing member. J L-.aeh panel must be securely nailed at each edge of the panel 3$ to the support. The width of individual boards of Panel Sheetrock will ^`1 sometimes vary sufficiently from 16" wide to make it im practical to attempt to center the edges on studs or framing ,A members previously spaced ex actly 16" o.c. In new construc l tion the studs should be erected just ahead of the Panel Sheetrock and spaced to allow for slight variations in panel widths rather than standard 16" o.c. spacing. If studs have been previous ly erected and the edges of the Panel Sheetrock Wallboard tend to occur off center to make nailing impossible, 1" x 2" wood furring strips may be nailed to the sides of the studs to provide bearing and a nailing surface. Fr tming must be care- fully aligned. NAIL1NG OVER MASONRY WALLS Panel Sheetrock may be nailed to exterior and interior furred out with 3" minimum nominal width wood furring '' strips applied vertically or 2" width strips applied horizon- s' tally 16" o.c. The furring strips /" --1 should be securely attached to the masonry walls, plumb and in a uniform plane. CUTTING Cut the face paper and the edges, then snap the board as shown, breaking the core. Cut the back paper from the reverse side and snap forward for a clean break. asonry w alls S3 *s 'j,i * m * v> '.s1 , A. y: ''' \ 1 75 NAILING PANEL SHEETROCK NAILING TO STUDS-- Use 3d. I'm" 15Ci;utgc :lW," flat head nail spaccil 12" o.c. (approxi mately 3 lbs. per 1.000 sq. ft.). PLAIN PANEL NAILING TO FURRING STRIPS-- Use 3d, I'.h" long nail spaced 12" o.c. Space nail as Car from the edge as possible and still drive it at a right tingle to board ami into undetlying framing or flaring. Dim ple board lightly with final blow of the hammer taking care not to deform the rounded edge of the board. Fill dimples over nail heads with 3 coals of Perp-a-tape Ce- ment. Over an extended period of time there may be some discoloration of the paint film over the featured round edge joints of panels over horizontal furring strips due to breathing caused by temperature and humidity differentials on each side of the wallboard. However, the period before which this discolor ation may be noticeable w'll probably not be less than the normal rcdccoration period. NAILING TO STUDS-- Predccorated Panel Sheetrock is nailed with I'/" long matching colored nails spaced 12" o.c. (ap proximately 2 lbs. per 1,000 sq. ft.). Drive nails flush with the surface, using plastic headed ham mer to prevent chipping the nail head coating. PREDECORATED PANEL NAILING TO FURRING STRIPS-- Use I'/h" long predccorated nails spaced 12" o.c. No additional fin ish normally required. Corner Construction--for a true fit at internal corners, scribe the t'/a" Matching colored nail corner on a piece of Panel Sheetrock to be used as a pattern. Measure the width top and bottom and use the pattern for mat king the corner panel to be cut. internal angles of plain Panel Siil liltuKK may be finished with I'ere-a- I'Ai'E Joint System, Inside corners of predccorated Stir.t: irotk may be butted together over which may be attached a wood quarter round or cove mold painted to match. Outside corners of plain Panel Sheeirock may be finished with Perf-a-bead or Dur-a-uead Corner Reinforcement in the same manner as regular Sheetrock Wallboard. Corners of predccorated panels may be finished with wood trim stained or painted to be harmonious. 76 BB026 19'27 adhesive application Panel Sheetrock Wallboard may be applied over existing surfaces that are sound and sufficiently true to permit reasonable continuity of contact be tween the adhesive and the surface of the base. In neiv construction Panel Sheetrock may also be laminated to a base layer of %" gypsum wallboard erected horizontally or */" Bxnhord, Gyp sum Backing Board, erected on framing. In remodeling; work when applied over existing surfaces, all wallpaper, calcimine, and poorly adhered, loose or scaly paint must be removed. Surfaces textured on a medium to coarse pat tern must have the high points of such texture removed by appropriate means. Areas of plaster that are loose, badly cracked, or poorly bonded to the plaster base, must be removed and the surface brought into a rea sonable continuous plane with the rest of the wall by nailing in place gyp sum board, cut to fit and shimmed out as required. Insulation board sur faces that are badly warped or buckled betwee" studs, and are more than ta" out of plane are not satisfactory bases. Likewise surfaces of cxp-uni hoard or insulation board that are loose must be renailed as required. During refinishing work the trim at the ceiling, base, doors and windows must generally be removed. Before the installation is finished, a U wide Trip of wood must be used to fill the gap left under the replaced trim around doors and windows. It is generally easier to use U.S.G. No. 400 Metal Trim in lieu of wood trim and therefore achieve a flush effect. PANEL SHEETROCK APPLICATION Assemble materials in the center of the room to permit easy access to all wall areas. After removing all wrappings from the bundles of Panel Sin I i- rock, place each piece face down in a pile on sawhorses, work table or clean floor. . MIXING ADHESIVE Perf-a-tape Joint Cement (embedding type only) is mixed using approxi mately 22 pints of water per 25 lbs. of dry powder. GENERAL CONDITIONS Heat should be provided to maintain a continuous and uniform temperature range of 45 to 70F. unless adhesively applied, then maintain a range ol 55" to 70'F. Ventilation must be provided to eliminate excessive moisture JOB LAYOUT 1. Before starling application, plan the layout of the panels. In all cases, joints in the face layer should occur between underlying joints in base layer. If a large window, door or fireplace is a wall feature, center the panels or the joints so that a balanced effect is achieved. 2. If the wall does not have an opening to feature, arrange the panels so the two end panels are approximately the same width. Avoid narrow strips that may be difficult to install. 77 A normal variation of color tones may exist between individual boards of Striated Panel Smilikock. Panels should be laid out prior lo erection and sorted to avoid unpleasant color contrast between adjacent boards. The range is so slight that contrasting tones will blend at corners. Like shades should be used on same wall. Similarly when Kanch Pine Panel is used, it is to the advantage of the finished appearance, that the panels be laid out prior to erection and inter-mixed from the original bundles to eliminate the occurrence of a possible pattern repeat of the design. SPREADING ADHESIVE Use a 2-notch spreader blade (made on the job). Fill the blade about half full of mixed Pl.Kl-a-tapi: Cement. Draw the spreader the full length of the panel applying downward pressure on the lop of the blade leaving two sharp firm ridges and a minimum of cement between ridges. CARRYING CEMENT FROM PANEL TO PANEL Without moving the spieadcr. shove the top board forward about 10". Then continue spreading cement on the top board over the end onto the underlying board, as shown. 'I he top panel is now ready to ap ply. To spread cement on the next panel, reverse the direction of the spreader and continue. He careful to keep cement off the edges of boards. Spreading cement on narrower panels is accomplished with a i-notch blade of similar design (also made on the job) one ribbon on panels 6" wide; two ribbons on panels 10" to 16" wide. Cut-outs are replaced after the board is cut to fit, the joint cement spread and then the cut-outs are discarded. Start the wall application by placing the first panel at a corner. Press the board against the back ing surface to assure adhesion and plumb with a carpenters' level. Drive 5d, I5/h" cooler type nails at top and bottom of each panel located so as to be covered by baseboard, picture moulding, or other trim. This holds panels in place until adhesive hardens. No. 400 USCi Metal Trim may be used at ceiling angle, applied prior to the erection of the panels. To insure tight joints, apply force to the leading edges of every panel with a length of 2x4 stud. Check every third panel with car penters' level to be sure panels are plumb. Over uneven surfaces it may occasionally be necessary to nail down an edge in position with a 4d finishing nail driven at an angle. 3B026 19 2ft Miscellaneous Application Methods CONTENTS METAL WINDOW INSTALLATIONS....................................................... PAGE 80 APPLICATION OF SHEETR0CK ON RADIANT HEATED CEILINGS.......... 81 SLIDING DOOR LAMINATION................................................................. 82 SHEETR0CK GYPSUM WALLB0ARD AS A BASE FOR CERAMIC, PLASTIC, METAL TILE AND PLASTIC WALL PANELS....................... 84 Vz" AND SHEETR0CK WALLB0ARD ON OPEN PORCH AND CARPORT CEILINGS AND SOFFITS OF EAVES AND RAKES ... 88 MISCELLANEOUS APPLICATION METHODS METAL WINDOW INSTALLATION In conjunction wilh metal window installation, builders normally allow V" to Vi" space between the metal windows and the end of Sheetrock Wallboard. This space is filled with a caulking compound prior to painting. This method of installation, after a year or more, allows moisture from condensation on the metal window frame to penetrate into the end of the gypsum wallboard and may result in paper delamination from the core. By placing No. 400, No. 200-A U.S.G. Metal Trim or No. 300 Perf-a-trim between the window and the board, protection will be provided against moisture penetrating the core of the Sheeirock. . APPLICATION OF SHEETROCK ON RADIANT HEATED CEILINGS 3B026 1929 MISCELLANEOUS APPLICATION METHODS SHEETROCK Return for Openings Where Aluminum or other Metal Sash is to be Installed Waterproof insulating tape, 1/32" thick, wide is used to separate metal sash and metal trim and will provide some measure of insulation between the two different metals. Direct contact of an aluminum frame and metal trim in the presence of condensation moisture may cause an electrolytic deteriora tion of the aluminum frame. HOT WATER TYPE RADIANT HEATING SYSTEM During recent years the use of radiant heating systems has become more prevalent in building construction. When Sheetrock Wallboard is to be used on ceilings having radiant heating, the following recommendations will help to ensure best results: Design 1. In radiant heating systems where Sueetrock Wallboard is used, the maximum surface temperature of the Sheetrock must not exceed 115' F. Application--Hot Water Type System 1. Apply Insulating Sheetrock parallel to the joists with the aluminum foil facing downward, as a reflector behind the heating coils. 2. Nail 2" x 2" furring strips 16" o.c. over the Insulating Sheeirock and at right angles to the joists. Wood must be dry and thoroughly seasoned to avoid movement of green lumber in the heated space. 3. Suspend heating coils from the joists, at right tingles to them and never from the Sheetrock Wallboard alone. Heating coils shall not be in direct contact with the Sheetrock surfaces. 4. Use only that thickness of Sheetrock on which the Healing Hngineer has based his design. For example, do not substitute ' Sheeirock for the face layer when the design calls for and is based on Vi" Sheeirock. 5. Apply the face layer in the normal manner, at right tingles to the furring strips. " 6. Do not operate radiant heating system until after taping and finishing of ceiling joints is completed, and cement has thoroughly dried. 80 81 SLIDING DOOR LAMINATION Sliding Door Frame Sheetrock is laminated to the framing members with Pert-a-tape joint cement (embedding type onlyi. This HELPS to prevent "nail pops" and eliminates the possibility of nails protruding through the usual TV backing of the frame. After installing the sliding door frame, check to make sure there is sufficient backing where the Sheetrock panels join. Normally, this is about 4' up from the sub floor. I ( 33026 1930 Shoring Once the wallboard is in place, pieces of wood or strips of Snrr. frock are temporarily nailed to the frame with 6d double headed nails to hold the Sheetrock firmly in place while the cement is drying. Adhesive Application Properly measure and cut the Sueeirock to fit over the frame. Using a spreader blade (sec chapter--tools I, spread a liberal amount of regular Perf-a-tape joint cement on that section of sliding door frame to be covered first (normally the top section). This prevents pre-dry ing of the adhesive. The Perf-a-tape joint cement should be mixed to a con sistency which will flow easily under the spreader blade, yet retain ridges when applied to the backing. \ Application of SHEETROCK Immediately following the application of cement, prefmed Sueeirock Wallboard is applied to the upper section of the frame. The lower section of the frame is then spread with cement and pre fitted Smeetrock Wallboard is applied. Finish When the Perf-a-tape joint cement has dried (usually overnight), remove the temporary shoring. Fill all of the remaining nail holes in the wallboard with Perf-a-tape Joint Cement and finish the wallboard in the normal manner. Finally apply the finish trim. MISCELLANEOUS APPLICATION METHODS ST SHEETROCK GYPSUM WALLBOARD AS A BASE FOR ADHESIVE APPLICATION OF CERAMIC, PLASTIC, METAL TILE AND PLASTIC FINISHED WALL PANELS Framing 1. Framing members should be plumb and true. 2. All framing around tub enclosures and shower stalls should allow sufficient room so that the inside lip of the tub, prefabricated receptor or hot mopped subpan should be even with the face of the gypsum wall board. This will necessitate furring out from the studs the thickness of the Sheetrock Gypsum Wallboard to be used (%", V2". Vs") less the thickness of the lip, on each wall abutting a tub, receptor or pan. 3. Furring of the proper thickness should be applied as required parallel to the lip of receptor, pan or tub. The lop of furring or if beveled, the start of bevel should be flush with the upper edge of receptor, pan or tub. 4. A continuous metal spacer strip as specified under the "Materials" section (below) should be applied with the 3A" leg behind the furring with the apex of the angle abutting the top surface of the furring and the Ys" leg protruding away from the stud face. (Note: If a metal spacer strip is not used the wood furring must be beveled as shown in details). 5. (a) For walls to be surfaced with ceramic tile over 'A" thick: When Vs" SitEETROCK Gypsum Wallboard is to be used on studs spaced 16" o.c. or V2" or 5/" Sheetrock Gypsum Wallboard on studs spaced more than 16" o.c., suitable blocking should be installed between all studs; one row of blocking located approximately 1" above the top of the tub or receptor and another row at the mid point between the tub and ceiling. (b) Blocking is not required for Vh" Sheetrock Gypsum Wallboard on studs spaced 12" o.c. or less, or for V2" or Fit" Sheetrock Gypsum Wallboard on studs spaced 16" o.c. or less. 6. Appropriate blocking, headers or supports should be provided to support tub, other plumbing fixtures, and to receive soap dishes, grab bars, towel racks and similar items as may be required. Materials Sheetrock Gypsum Wallboard may be V", \'i" or Vh" in thickness. NOTE: Insulating (foil-backed) Sheetrock Gypsum If 'allboard should not be used as a backing material in shower stalls or tub enclosures. Perf-a-tape Joint System is recommended for treating joints and conceal ing nailheads. The metal spacer strip should be fabricated of 16 gauge galvanized steel, with one leg Vs" wide and one leg 3A" wide bent at a 45 angle. 84 BB026 1931 Materials (continued) The surface scaler should be either the water resistant adhesive rec ommended by the manufacturer of the surfacing material spread in a continuous film 1/16" thick over the entire surface of the wallboard or a waterproof scaler such as varnish. Either to be applied after joints are "treated". Shellac should not be used. The adhesive used for application of the surfacing material should be approved by the manufacturer of the surfacing material for use over gyp sum wallboard. The surfacing material should provide a durable surface and prevent the passage the free water to the backing material, also it should prevent the passage of water vapor which may lead to condensation within or on the surface of the backing material or framing members. Waterproof receptors, pans or sub-pans should have an upstanding lip or flange a minimum of 1" higher than the water dam or threshold con tained in the entry way to the shower. Application Shower pans, receptors or tubs should be installed prior to the erection of the gypsum wallboard. They should be properly furred away from the framing members as specified in section on "Framing" (Page H4i, and installed so that the inside surface of the lip or upstanding leg of the receptor or pan should be in alignment with the surface of the gypsum wallboard. y,,", Vi" or s/h" Sheetrock Gypsum Wallboard should be applied hori zontally with the factory edge (paper bound) abutting the lop edge of the metal spacer strip or bevelled furring, which should allow a minimum of a `A" space between the lip of the receptor, tub or sub-pan and the gypsum wallboard. The Sheetrock should be nailed in the conventional manner except where ceramic tile over Vi" thick is to be used as a surfacing ma terial, then nails should be spaced a maximum of 4" o.c. All joints between adjacent pieces of wallboard, including those at all angle intersections, should be treated with Perf-a-tape Joint System in the conventional manner. Prior to the erection of surfacing materials, a waterproof sealer should be applied to the entire surface of the gypsum wallboard. treated joints and angles. When the adhesive is used as a sealer, it should be applied as a separate operation, independent of the application used to adhere the sur facing material. All edges of cut-outs made in the gypsum wallboard for pipes, fixtures, etc., should be sealed in a like manner. All openings around pipes, fixtures, etc., should be caulked flush with waterproof, non-hardening caulking compound. The surfacing material should be applied down to the top surface or edge of the finished shower floor, return or tub and installed so as to overlap the top lip of receptor, pan or tub. The surfacing material should cover the following areas: (1) Over tubs without'shower heads--6" above the rim of the tub. (2) Over tubs where showers occur--a minimum of 5 feet above the rim ` or 6" above the height of the shower head, whichever is higher. (3) Shower stalls--a minimum of 6 feet above the shower dam or 6" above the shower head, whichever is higher. (4) All jambs in shower stall should be covered to a like height. (5) All areas extending beyond the face of the tub should be covered a minimum of 4" from the required height to the finished floor of the bathroom (belovy rim of tub). Areas beyond an exterior corner excluded. 85 MISCELLANEOUS APPLICATION METHODS Where plastic finished wall panels arc used as a surfacing material, the fol lowing precautions should be taken: ( 1) Only the type and shape of mouldings recommended by the manufacturer of the surfacing material should be used. All interior and exterior angles should be treated with mouldings containing a flange projecting behind the surfacing material on each leg of the angle. Only recommended tub mouldings should be used at the base where the surfacing materials abut the tub, shower floor or curb. Such mouldings should be set in caulking compound. (_) A bead of caulking compound should be applied at the angle formed by the gypsum wallboard backing and the moulding used around the top edge of the surfacing material to prevent leakage of water behind the moulding. Where other types oj surfacing materials are used, the following precautions should be taken: ( I) All joints should be grouted in such manner as to leave no voids for water penetration. (2) Nonsetting caulking compound should be applied between the wall sur facing materials and the floor of the shower or' rim of the tub. (3) The angle between the edge and the surfacing material should likewise be caulked. BB026 1932 MISCELLANEOUS APPLICATION METHOOS 86 87 THE USE OF VC' AND Vs" SHEETROCK ON OPEN PORCH AND CARPORT CEILINGS AMD FOR SOFFITS OF EAVES AND RAKES [1 he purpose of the following recommendations is to provide provisions which, under all normal conditions, will protect the Shff.irock IVallhoard from 1 owing into direct contact with water.) 1. Spacing of Supports and Board Placement PORCH AND CARPORT CEILINGS Framing should ho spaced not more than 16" o.c. for Vi" Smeetrock and 24" o.c. for -Vs" Smeetrock. The board should be applied per pendicular to supports. SOFFITS OF EAVES AND RAKES For eavc or rake projections of 26" or more, framing must be spaced not more than 16" o.c. for V2" board and 24" for %" board. The board should be applied perpendicular to the framing members. For eave or rake projections of 26" or less, framing may be spaced 24" o.c. provided that both edges of the Smeetrock parallel to the building wall are supported by moldings or other suitable means. The board may be applied either perpendicular to or parallel to the framing. 2. Flashing Under Shingled Roofs In areas subject to freezing temperatures, shingled roofs should be provided with eave flashing strips of not less than 55 lb. smooth rolled roofing or two layers of 15 lb. felt cemented together extending inside the face of the exterior walls not less than: (a) 24" for pitches under 5 in 12. (b) 12" for pitches of 5 in 12 or over. If the pitch or overhang requires the strip to be wider than can be covered by a single strip, all laps are to be cemented. METAL ROOF EDGE Suitable metal drip edge extending a minimum of 3" under the shingles must be provided at all roof edges. 3. Facia Boards Facia boards of sufficient width to provide a minimum of !4" drip below adjacent trim on the underside of the eave, rake or ceiling must be provided. 88 <! A7 '-^v^:1 B2026 1933 4. Ventilation PORCHES AND CARPORT CEILINGS Attic spaces above open porches and carport ceilings shall be pro vided with ventilation in compliance with F.H.A. requirements for attic spaces over living quarters. Where the Smeetrock is applied direct to rafters, vents should be provided at each end of each span as required in the following section. SOFFITS OF EAVES AND RAKES Rafters or joist spaces shall have a minimum of 2" x full width (space between rafters or joists) screened vent at each end of each space. The vent openings are to be located within 6" of the outer edge of the eave and be framed with wood. 5. Insulation Areas covered herein that do not have a heated living space above are not to be insulated. 6. SHEETROCK Adjacent to Brick or Masonry Work Wood facings must be provided between Smeetrock Wallboard ceil ings or soffits of eaves and rakes and brick or masonry work of any kind. 7. Nails and Nailing Vj" Smeetrock should be nailed with l',4" GWB-54 nails. ?" Sheetrock should be nailed with Hi" ring shank nails (see chapter --board application and finishing--"Nail Specifications") spaced not more than 8" o.c. along framing supports. All edges and ends around the perimeter must be supported by moldings of sufficient size and nailed securely to prevent sagging of the Sheetrock. All nails in the field of the board shall be driven in the manner pre scribed for interior finish work. 8. Back-Blocking For best results, it is recommended that all joints in ceilings be backblocked and end joints floated. This, however, is not a mandatory requirement. 9. Finishing Joints All joints and nail heads are to be finished with Perf-a-Tspe and Perf-a-tape Cement in accordance with directions. 89 MISCELLANEOUS APPLICATION METHOOS 10. Painting All e\posed Mitlnces should he painted with a minimum of 2 coats of it uooJ piiule exterior pmni. LIMITATIONS 1. Sun. I ko( K Wall board is not tccommcndcd for sollits or carpoit or open porch ceilings which project upwards and away from the build ing proper. 2. Joint treatment and painting should not be attempted during freezing or other adverse temperature or drying conditions. For best results, apply joint treatment and finish during a uniform temperature range of 55 F. to 70 F. 3. USG Shea t iiino is not recommended due to undesirable color and surface unsuitable for painting. Technical Data BB026 1924 CONTENTS FIRE RESISTANCE RATINGS FOR SHEETROCKWALLBOARD CONSTRUCTIONS (TABLE) ....................... PAGE 92 CONSTRUCTION REFERENCES (PARTITIONS) . 93 CONSTRUCTION REFERENCES (CEILINGS) CONSTRUCTION REFERENCES (COLUMNS)...................................... 94 95 FIRE HAZARD CLASSIFICATION 96 . SOUND TRANSMISSION RATINGS ............ . INSULATING SHEETROCK WALLBOARD VAPOR BARRIER DATA . . 96 96 VAPOR BARRIERS .. . 96 INSULATION................................................................... 96 EFFECT OF VAPOR BARRIERS ON CONDENSATION . 97 THERMAL RESISTANCE OF INSULATING SHEETROCK . 97 VAPOR PERMEABILITY OF INSULATING SHEETROCK .................... 98 BENDING RADII OF SHEETROCK WALLBOARD .99 SHEETROCK WEIGHTS . 99 PAINTING AND FINISHING GUIDE 100 TECHNICAL DATA 90 9J TECHNICAL DATA FIRE-RESISTANCE RATINGS FOR SHEETROCK WALLBOARD CONSTRUCTIONS Construction References--SHEETROCK Fire Resistance Ratings PARTITIONS A. 2x4 wood studs spaced 16" o.c. (fire slopped at mid-height i faced both sides with Vi" Sheetrock. Board nailed with 5d cooler type nails spaced 7" o.c. Board applied either vertically or horizontally. Joints reinforced and concealed with Perf-a-tape Joint System. B. 2x4 wood studs spaced 16" o.c. (fire stopped at mid-heighti faced both sides with Sheetrock Firecode NVallboard. Vs" board nailed with 6d, cement coated Vi" diam. flat head, 1 Va" long nails. Vi" board nailed with 5d, cement coated lr;hi" diam. flat head, 15" long nails. Nails spaced 7" o.c. Joints reinforced and concealed with Perf-a-iape Joint System. C. 2x4 wood studs spaced 16" o.c. (fire stopped at mid-height) faced both sides with 'A" Sheetrock. Board nailed with 5d cooler type nails spaced 7" o.c. Mineral wool fill (0.6 to 1.2 lbs. per sq. ft.) between studs. Board applied cither vertically or horizontally. Joints reinforced and concealed. D. 2x4 wood studs spaced 16" o.c. (fire stopped at mid-height). Studs faced both sides with 2 layers of Va" Sheetrock. Base layer applied with long edges parallel to and abutting on studs. Board nailed with 4d. cement coated cooler type nails spaced 8" o.c. Face layer applied horizontally, ends abutting either between or over studs and nailed (permanent) along framing with 5d, cement coated nails spaced 8" o.c. The 2 layers arc bonded to gether with Perf-a-tape cement. Face layer joints are reinforced and con cealed with Perf-a-tape Joint System. E. 2x4 wood studs faced both sides with regular Sheetrock Waliboard. Rating applies to non-bearing partitions only. Construction: first layer ap plied vertically with 5d. cement coated, diam. head. 1%" long nails spaced 6" to 8" o.c. Finish layer applied horizontally with 8d. cement coated, 'A" diam. head, 2-l" long nails spaced 6" to 8" o.c. Joints rein forced and concealed with Perf-a-tape Joint System. F. 2x4 wood studs spaced 16" o.c. (fire stopped at mid-height) faced both sides with 2 layers s/s" Sheetrock Firecode 60. Both layers nailed with 6d, cement coated, Vi" diam. fiat head. IVa" long nails. Base layer nails spaced 6" o.c. Face layer temporary nails spaced 12" o.c. Base layer ap plied with long edges parallel to and joining on studs. Face layer applied at right angles to base layer. 2 layers adhesively bonded together with Pi.rf-a- tape Cement--cement spread on back side of face layer in ribbons 11" wide by Vi" high, 1" apart. Face layer joints treated with Pi:kf-a-i wi: Joint System. G. Trussteel Studs spaced 16" o.c.. attached to Trussteel runner track, to which a base layer of Is" Bxnbord is attached by means of Tkcs-lok TL-1 clips. End joints are located between studs and secured with Uridjoint 92 B-l clips. The face layer is Sheeirock for 45 min. fire endurance rating or 1 i " Shieirock FlRtcont: 45 for 1-hr. rating applied vcitically and adhesively bonded to Bwdord with Perf-a-tape Joint Cement applied unifoimly in ridges over back of Sm'it frock with notched spreader. For I-hr. rating apply sufficient adhesive to cmnphtcly cover backing boaid. Joints in face layer do not occur over joinings of base layer. Face layer joints are treated with l'i rf-a- i are Joint System. H. Nailable steel studs, 2" x 358" consisting of two formed channels spot welded back to back with webs deformed to exert a clinching action on nails driven into the stud, are spaced 24" o.c. A single layer of Sheeirock Firecode 60 is applied to both sides of the studs and nailed with 7d cement coated cooler nails spaced a maximum of 8" o.c. Board is applied vertically with the tapered edges falling on the center line of the studs and anchoied by nailing through the joint using diamond shaped clips under the nail head. Joints rein forced and concealed with I'erf-a-tape Joint System. CEILINGS I. Wood joists spaced 16" o.c. faced on top with rough and finish floor and on underside with Vi" Sheet rock Wallboard. Sheetrock nailed to joists with 134" No. 12 ga. nails having Vi" heads, spaced 6" o.c. Joints concealed with Perf-a-tape Joint System. J. Wood joists spaced 16" o.c. faced underside with Sheeirock Firecode Wallboard applied horizontally and finished on top with 1" nominal wood sub and finish flooring with rosin sized paper between. 5/h" board nailed with 6d, cement coated, 'A" diam. flat head, Wa" long nails. 'A" board nailed with 5d, cement coated, lr;!u" diam. flat head, Wa" long nails. Nails spaced 6" o.c. Joints reinforced and concealed with Perf-a-tape Joint System. K. Steel joists (open web design) spaced 24" o.c. supporting 2" of reinforced concrete on 3.4 lb. 3/a" ribbed diamond mesh metal lath. Nailing channels spaced 16" o.c. wire tied to bottom cord of joists. Firecode board nailed to nailing channels with No. 11 ga. )[," diam. head, 1!4" long annular ring nails spaced 6" o.c. Firecode Wallboard applied with long edges perpendicular to channels. Ends may be secured by (A) breaking joints between nailing channels and back-blocking with Firecode board, (B) providing double nail ing channel at ends of abutting boards (not necessary to treat the joints to obtain a one hour rating). NOTE: For l'/i hour rating, the steel joists, floor, nailing channel and s/s" Baxbord Firecode 60 base layer application is identical to that described above, except nail base layer 7" o.c. Apply Vi" Sheetrock Firecode 45 face layer over base with long edges perpendicular to channels nailed through the base into channels with 13A" annular ring nails spaced 6" o.c. COLUMNS BB025 1936 L. Steel column protected with two layers ol Sheeirock cm and applied as in four-layer consliuclion below, except inner layer is tied around column with double strands of IS ga. tie wire, spaced 15" apait. Corners of face layer finished with Perf-a-tape Joint System. M. Steel column protected with three layeis of Sheeirock cut and applied as below except first two layers are cemented and clinch-nailed together; then tied around column with double strand of 18 ga. tie wire spaced 15" apart. Third layer is then applied and corners are finished with Pert-atape Joint Sytem. N. Steel column protected with tour layers of Sheetrock cut in widths to span the flanges or teentrant spaces and to bear on the edges of the flanges and of the other layers of boaid with edge overlap staggered; cut in lengths to cover the col umn height. Bach layer applied vertically with joint cement to bond inner layer to column and succes sive layers to each other. I ied around the column with double strands of 18 ga. tie wire spaced 15" apart after third layer is in place, l ace layer held in place with wood forms until cement is haiJencd. Corners finished with Perf-a-tape Joint System. TECHNICAL DATA ! X t I It Fire Hazard Classification A flame spread rating of 10 to I 5 is applicable to Siieetrock Gypsum Wall board. Sound Transmissions Sheeirock Wallboard partition systems have provided average sound transmis sion loss values up to 45 dh. based on tests at recognized sound testing labora tories. These values will vary depending upon the mass (weight), extent of isolation of the partition faces and openings through the partition. In general the greater mass (wallboard thickness) and greater isolation (staggered studs etc.) will give higher sound transmission loss values. Truss!r.r.i. Stud paitition framing is particularly adaptable to locations where sound transmission loss is a design consideration. (Sec chaptci--svsirMs--I'agc 64.) Sound transmission from one room to another is not dependent on the reduction afforded by the wall construction alone. Of great importance is the transfer through the floor and ceiling construction, electrical boxes placed back to back, cracks around door openings, etc. and transfer through ducts, piping or other utilities common to the adjacent rooms. Insulating SHEETROCK Wallboard (Foil Back) Vapor Barrier Data Insulating Siieetrock Wallboard is made by laminating a sheet of bright aluminum foil on the back surface of any Siieetrock Wallboard except Panel Siieetrock. It is an effective vapor barrier for exterior walls and ceilinps when applied (II with foil surface next to the studs in single layer application or (2| as the base layer (with foil surface next to the studs) in the USG Double Wall System. A thermal insulating value is achieved when Sheeirock is installed with the aluminum foil facing a ``dead" air space of yA" or more. Vapor Barriers Provides an ellicicnt vapor barrier which resists the passage of moisture through the interior lining of exterior walls, and minimizes the possibility of condensa tion within the wall, and of consequent failure of the exterior paint film. Vapor barrier should be on the warm side of the wall. Insulation Insulating Sheetrock installation keep interiors cooler in summer by reducing heat flow into the home, and in the winter keeps interiors warmer and fuel bills lower by reducing the heat flow upward and outward. BB026 1937 Effect of Vapor Barriers on Condensation Air always contains moisture in the form of an invisible gas (water vapor), l ike all gases this water vapor exerts pressure, the greater quantity of it present in the air at a given temperature, the higher the pressure. Conse quently. just as water at a higher level will flow to a lower point unless a barrier is interposed, so water vapor at a higher pressure will flow to an area of lower pressure unless a suitable harrier intervenes In the typical example shown ( Page 981 the higher water vapor on the inside exerts a higher pressure than exists outside. It. therefore, flows to wards the outside, progressively meeting collier and colder temperatures. As the temperature decreases, the air can hold less and less water v.,por without becoming saturated with it. So. at a point near the back of the sheathing in both walls, tempeiattires are reached where the air can no longer hold the waiter vapor moving into it. and the excess water vapor condenses within the construction. However, the rate of vapor flow toward the outside in the "conventional wall" is about 20 times as great as it is in the "vapor barrier wall." because the vapor permeability of the StirriKoiu in the former is about 20 times that of Sheeirock and foil in the "vapor barrier wall." As a result, the condensation in the "conventional wall" is about 2'/z gallons per one thousand square feet of wall per day, whereas only about % pint can be condensed in the same area of "vapor banier wall." When the atmospheric conditions indicated are of considerable duration, the amount of condensation in the "conventional wall" is sufficient to dam age the interior decoration, exterior paint, or any of the other wall compo nents. In the "vapor barrier wall." however, the quantity of condensate is so minor as to be readily dissipated. Thermal Resistance of Insulating SHEETROCK I he thermal resistance provided by an air space faced with Insulating Siieetrock is approximately equal for horizontal heat flow through walls in both summer and winter conditions and upward heat flow for ceilings under winter conditions. Thermal resistance to downward heat l'.ow for ceilings under summer conditions is approximately three times that for upward heat flow under winter conditions. FOR INFORMATION ON CALCULATING THERMAL RESISTANCE OF AIR SPACES FACED WITH REFLECTIVE INSULATION (INSULATING SHEETROCK), CONSULT THE LATEST EDITION OF THE HEATING VENTILATING AIR CONDITIONING GUIDE PUBLISHED BY THE AMERICAN SOCIETY OF HEATING AND AIR CON DITIONING ENGINEERS, INC. (See illustration on importance of vapor barrier on Pc.pe 9S.J TECHNICAL DATA 96 97 ILLUSTRATION OF IMPORTANCE OF VAPOR BARRIER 1 NSfDE AT MOSPHERE 70`r 4 by. 3.63 0.332 IN. MG. TEMPERATURE RELATIVE HUMIDI T Y GR A (NS MOISTURE PER CU. FT. RESULTANT VAPOR PRESSURE OUTSl OE ATMOSPHERE I0`F 90 V. 069 0.067 IN.HG. Vapor Permeability of Insulating SHEETROCK A vapor barrier construction should not have a vapor permeability of more than 1.00 perm.f Insulating Sheetrock Wallboard meets ASTM requirements for a vapor permeability not exceeding 0.30 Pcrmsf for foil-backed gypsum wallboard. t 1 Perm = 1 grain per sq. ft. per hour, per inch of mercury vapor pressure difference. Bending Radii of SHEETROCK Wallboard 1 Thickness Lengthwise Width W 20'* 4 %" 7 V2 25' Vi" 5' 15' (lending two Vi" pieces successively permits radii shewn for Vi" SHEETROCK sheetrock Wallboard can be formed to almost any curved surface. To pply board, place a slop at one end of the curve and then gently and i.uluallv push on the other end of the board, forcing the center against he framing until the curve is complete. By moistening the face and back paper thoroughly and allowing the water m soak well into the core, the board may be bent to still shorter radii. \ lien the board dries thoroughly, it will regain its original hardness. SHEETROCK Weights I lie following are the approximate u-eights per thousand square feet of sheetrock Wallboard: SHEETROCK............................... ..................... 1097 lbs. :;r SHEETROCK (Plain)................................ .... .1526 lbs. la" SHEETROCK (Insulating)................................................................... 1556 lbs. V Panel SHEETROCK (Plain)....................................................... 1526 lbs. Woodgrained SHEETROCK..................................................... 1556 lbs. !'b" Ranch Pine Panel SHEETROCK................................................... 1556 lbs. ;,V Striated Panel SHEETROCK.............................................................. 1556 lbs. Va" BAXBORD (Plain) ............................................................................... 1526 lbs. !'a" BAXBORD (Insulating) ..................................................................... 1555 lbs. V2" BAXBORD (Plain).................................................................................... 2025 lbs. V/' BAXBORD (Insulating)..................................................................... 2070 lbs. V," SHEETROCK (Plain)...............................................................................2025 lbs. V2" SHEETROCK (insulating).................................................................... 2070 lbs. '//' SHEETROCK EIRECODE 45 .............................................................. 2120 lbs. V2" SHEETROCK EIRECODE 45 (Insulating)....................................... 2165 lbs. SHEETROCK FIRECODE 60 ................................................ 2640 lbs. Yu" SHEETROCK FIRECODE 60 (Insulating)............................... 2685 lbs. Vh" BAXBORD FIRECODE 60 Gypsum Backing Board. . . . 2640 lbs. Va" SHEETROCK (Regular Core) Wallboard....................................... 2640 lbs. Ye" SHEETROCK (Regular Core) Wallboard (Insulating).... 2685 lbs. All H eights subject to change. 98 99 TECHNICAL DATA 001 lltSSlSiM \ f.l. V PaintingtancbFinishmgLGuidetC ' , TYPE OF SHEETROCK WALLBOARO FINISH WANTED FIRST COAT FINISH COAT Plain-tapered edge; Vz"i V"t Vi". Plain Panel SHEETROCK Vi" & %" Beveled Edge SHEETROCK Flat or Velvet Pastel Colors SHEETROCK Sealer or TEXOLITE Primer (tinted to approxi mate shade of finish coat). TEXOLITE DURAVAL TEXOLITE Alkvd Latex TEXOLITE Standard Flat Oil Paint Semi Gloss TEXOLITE Vinyl Sealer. SHEETROCK Sealer (tinted to approximate shade of finish coat). 1 or 2 coats of TEXOLITE Semi-Gloss enamel as . required. Gloss TEXOLITE Vinyl Sealer. SHEETROCK Sealer. Then one coat Vi enamel and >/i enamel undercoater (tinted to approximate shade of finish coat). Apply finish coat of Gloss Enamel. Stipple TEXOLITE Vinyl Sealer. SHEETROCK Sealer (tinted to approxi mate shade of finish coat). 1 coat of TEXOLITE Ripple or 1 coat of oil-type stipple paint. Sand Finish 1 coat TEXOLITE Texture Woodgrained Ranch Pine Cherrywood Sablewood Ranch Pine Panel SHEETROCK Striated Panel SHEETROCK Texture Multi-Color Enamel Effect Wallpaper ' Note: Woodgrained SHEETROCK is pre finished at factory. If additional protection is desired apply-- TEXTONE or USG Tex ture Paint Not needed SHEETROCK Sealer (required for later removal of wallpaper). 1. Paste wax or 2. Satin varnish 1 or 2 coats TEXOLITE DURAVAL. TEXOLITE Alkyd Latex, TEXOLITE Standard. NEO-FLECK Odor less Multi Color enamel. Wallpaper or other wall covering. PRETINISHED AT TACtORY--NO OTHTR FINISH REQUIRED On Plain Panel SHEETROCK the wallpaper normally is split into widths of paper necessary to cover each panel from joint to joint The wallpnpei is then applied to Panel SMELTROCK wilh the joints in the wallpaper occurring directly over the joints m the Parrel SHEETROCK installation The unused narrow strip cut from the roll is then thrown away. When, due to the desiRM of the paper, it is necessary to use the full width of wallpaper to retain the pattern, the paper should be sht for joining over the |omts between the units of Panel SHEETROCK The remaining strip is then used to start the next panel, thereby prcscrvmp, the ricvupn If the paper is not cut at the joint between the panels of SHEET ROCK Wallbnard, as the wallpaper dries it will contract and tend to bridge the joint, with the result that at a later date an unsightly break or wrinkle will occur m the wallpaper over the joint VIVO TttlNHOJl ,ivc-,.mrwn&j* txii*.? -3?-; . is*' 03 CO o (NJ CTs UP UJ yy-wyyw*** g--tj DESCRIPTION OF TEXOLITE PAINTS SHEETROCK Sealer- Ready to use. quickly applied. Provides excellent "tooth'' for subsequent coats of paint. Seals ofT impurities, lays the nap of face paper, controls suction and equali/cs porosity over gypsum wall board face paper and joint finishing cement. Provides uniformly smooth suiface. Highly pigmented. One gallon will coyer up to 500 sq. ft. May be tinted. TEXOLITE Vinyl Sealer- Ready to use. quick drying scaler. Painting possible with oil paints in two to four hours depending on drying conditions. One gallon will cover up to 500 sq. ft. Highly pigmented. May be tinted. TEXOLITE Primer- in powder form ready to use with addition of watei. Provides excellent "tooth'', equalizes suction, locks in alkali. Ptoxides a haul, dependable prime coat for tiny type paint. Coxets up to 75 sq. ft. per pound. TEXOLITE Duraval-- Ready to use self-leveling, easy to apply, dries to a velvet finish within tin hour: leaves no "painty" odor. One gallon covers up to 500 sq. ft. It's highly washable with soap and water or a detergent. Apply with brush, roller, or spray. TEXOLITE Alkyd Latex-- Rcady-to-usc. self-leveling, easy to apply, dries within tin hour to a dead flat finish; leaves no ''painty" odor. One gallon covers up to 450 sq. ft. Highly washable with soap and water or a detergent. Apply with brush, roller, or spray. TEXOLITE Standard- Economical water-thinned paint in concentrated paste form. One-half gallon of water added to one gallon of paste provides \'A gallons of paint which will cover up to 800 sq. ft. Self-leveling, easy to apply, dries in an hour to a dead flat finish, leaves no "painty" odor. Cleanablc with mild soap and water. Apply with brush, roller, or spray. TEXOLITE Semi-Gloss Enamel-- Odor-less, alkyd semi-gloss enamel. Ready to use from the can. One gallon covers tip to 450-550 sq. ft. Apply by brush. TEXOLITE Ripple- Ready to use. smooth stipple-finish latex paint. Easy to apply with roller or brush and roller. One coat usually sufficient. No "painty" odor. One gallon covers up to 225 sq. ft. TEXOLITE Texture- Ready to use. sand finish latex paint. Easy to apply with roller or brush and roller. One coat usually sufficient. No "painty" odor. One gallon covers up to 225 sq. ft. TEXTONE-- In powder form ready to use with addition of water. Provides rugged, highly durable medium or heavy textured surfaces. Will cover farm one to four square yards per pound. USG Texture Paint-- In powder form ready to use with addition of water. Provides economy and versatility. Provides excellent medium or light textured surfaces. NEO-FLECK Enamel- Decorative multicolored enamel. Durable, highly washable, odor-less, non toxic, extremely tough. No prime coat required, l.ong life, Apply by spray only. Economical--only one double-spray coat required. BB026 1940 Tools CONTENTS TOOLS FOR SHEETROCK WALLB0ARDAPPLICATION............................ PAGE 104 AMES TOOLS DATA................................................................................. Ill PROCEDURE FOR ORDERING AMESTOOLS......................................... 112 VERTI-R0LL .......................................................................................... 113 A-3 DRY-WALL ADHESIVE GUN AND ALEMITE PUMP 114 SHEETROCK WALLBOARD TOOLS Measuring and Cutting (See Key on page 114 in this clwpler denoting additional availability of tools) . -'<* .. ' ; *S-' Straight Edge A calibrated metal straight edge with T-square used as a guide in making upright cuts across the full width of the board. It eliminates the need lor drawing lines and expedites accurate cutting. A metal or metal edge straight edge is preferred because it prevents the knife from cutting into the edge as the board is scored. * B026 I94i Steel Rule King size white face steel rule with Tru-Guide measuring aid and Tru- Saws Carpenters Cross Cut Saw (not shown) is generally used for making one side of a right angle cut at door or window openings. Wide tooth saw pi cl erable to minimize clogging with gypsum. (Available locally at haidwaie stores.) (Available locally at any hardware store, t ^ihS'tUv; Trimming Knife The Stanley Trimming Knife, with changeable blades is an increas ingly popular tool. A pocket knife or an awl may also be used. What ever the instrument, it should be kept sharp to cut the paper cleanly and score the core. Stanley Trim ming Knife No. 199. Stanley Tools Company, New Britain, Connecti cut. (Available locally at most hardware stores.)! A hook-nosed linoleum knife is an excellent cutting tool. However, the point must be rounded off ap proximately %" from the tip to avoid its gathering the paper of the Sheeirock Wallboard. (Available locally at any hardware store.) Key Hole Saw Used for cutting small openings. (Available lo cally at hardware stores.) 2"x4" wood block with metal lath stapled to face. Made on the job. Used to trim or smooth job-cut Sheeirock ends or edges. Utility Saw Used for cutting out small openings.'* Hammers The proper hammer for nailing Siiee i rock Wallboard lias a round edged, slightly crowned head which forms a "dimple" in the face of the board as the nail is "driven home". A hammer with a flat head and sharp edges will fracture the paper around the nail head, and these cracks around the hammer head imprint may eventually appear through the decoration. I he head of a i.athcrs' hatchet is too flat, its corners too sharp, and a hall-pecn hammer is loo heavily crowned. A regular hammer head may be easily crowned with a file, if neces sary. In driving the nails used in erecting Woodgrained Sheet rock Wallboard, a plastic headed hammer, a raw hide mallet, or a regular hammer covered with pliable leather should be used to avoid chipping the enameled nail head. 16 oz. Crown Head Carpenters' Claw Hammer (crown head) designed to dimple nails properly. (Available locally at most hardware stores.) Leather Tool Pouch Holds nine wallboard applica tion tools. * !> 'If- A Plastic Headed Hammer For driving special nails used with Woodgrained Siieetrock. (Avail able at most hardware stores.) Wal-Board Hammer The symmetrical convex face is de signed to compress the board and leave a perfect "dimple".* Plumb Wallboard Hatchet Also has a crown head designed to properly "dimple" the board. Checkered face designed to prevent slipping over nail heads. Fayette R. Plumb, Inc., Philadelphia, Pa. and St. Louis, Mo. (Available at most hardware stores.)! 1(76 Leather Nail Bag Soft leather riveted for long life--round bottom designed so nails won't "pack"--big belt loop.* Foot Power Wallboard Lifter I he Lifter shown here is de signed for moving board against the wall as it lifts. Available from B. E. Gillespie, Box 446, Refugio. Texas. (An alternate device or tloor jack may be made from a piece of 2x4 bevelcut on one end like a chisel. Such a tool may be used to raise the lower course of the horizontally applied Siieetrock Wallboard into nailing position. A piece of automobile spring leaf may also be used.) 313025 1942 Swearless Trimmer A tool designed to trim either -Is" or '/s" board edges or ends. Torrington Metal Products, 400 Riverside Ave.. Torrington, Connecticut. -- tf 7,1 All-Round Circle Cutter Cuts clean sharp round holes --up to 12" in diameter.* I IP HUM! .^a. .-vynC,*I Electric Mixers for PERF-A-TAPE Cement (Made on the job) While hand mixing of IT.rf-a-tape Cement is perfectly adequate, many appli cators are currently using electric mixers to good advantage. Power mixing saves considerable time, particularly on a large job where mixing in a central location is convenient. TYPE "A-' TYPE O Ul Mixing paddles may be any one of the above types or variations thereof con sisting of a diameter shaft about 24" long with blades welded thereto. Type "A" blades arc approximately I Vi" x 3" welded on at an angle of 45 degrees. Type "B" has three equally spaced blades approximately 2" x 3Vi" welded in line with the shaft. Slots approximately 1" x 2" are cut out of the blades to allow the cement to work through the blades in a folding action. Type "C" has blades approximately 2" x 2" welded at a 45 degree angle on the bottom leg of a 4" x 6" stirrup. Material for the blades is '/" strap iron, for the shaft, Vs" round iron--both available at most wrought iron fabricating shops. Power is supplied by a Vi" heavy duty electric drill operating on 115 volts AC-DC at not over 400 rpin. Drills operating at higher speeds will whip air bubbles into the cement, rendering it unfit for finish coat purposes. If available at reasonable cost, drills of 200 to 300 rpm arc even better. Mixbit Blades Mixbits counteracting blades churn and mix joint cement into a smooth, creamy mix. Designed for use with V2" electric drill. Available from: Park Manufacturing Company Grant Park, Illinois! <33026 19iI3 USG PERF-A-TAPE Corner Toot U. S. Gypsum Company (Available locally at lumber dealers, paint or hardware stores.) Spreader Blades Made on the job from semi-rigid galvanized steel sheet metal approximately 5" x 10". Notch the long edge. Hi" apart with round 9jii" wide inverted "V", \ 2" deep notches. A common trowel may be prepared in same manner. (See chapter -- systems--''The Double Wall System.") 2 and I notched spreader blade made on job and suggested for use with Panel Sun: 1rock adhesively applied. (2 notch! 1 V/i" top, 15" bottom, 51/2" high, 6V2" wings. (1 notch) 2" top tapering to 5". 2" bottom. 5V4" wings. Notches Vs" wide inverted "V" shape, Vs" deep. Notches placed 1" in from blade edge on 2-notch blade. Made of semi rigid galvanized sheet metal. 11" Trowel (Available locally at most hardware stores.) Restaurant Potato Masher Used to hand mix joint cement. (Available at most restaurant supply companies or Ames Taping Tools. Inc.. Belmont, Cali fornia.) v mm imvw I 1I 109 | PViNWP1 4" USG Joint Steel Finishing Knife U. S. Gypsum Company Either plain (as shown) or hammer head handle. (Available locally at lumber dealers, hardware and paint stores.) Quic-Kutter E3026 194 These tools tire designed to pro duce perfect die-cut openings in gypsum wallboard walls and ceil ings. Shown at left are the tools recommended by the manufacturer for cutting the most common sizes and shapes. Available from: Hartmeister Manufacturing, Inc.. 1544 Lowell Blvd., Denver 4, Colorado. Hand Finisher 5" USG Steel Joint Finishing Knife U. S. Gypsum Company Picture at right shows Ames Hand l-'inisher in use during the applica tion of the first coat of cement over Perf-a-tape. Either plain (as shown) or hammer head handle. (Available locally at lumber dealers, hardware and paint stores.) COMPLETE LISTING OF AMES TOOLS, DATA, DESCRIPTION Automatic Taper (Bazooka) Applies tape and cement simultaneously to flat joints and corners ................................................................... Rental Corner Applicator Applies cement to corners preparatory to laying in tape by hand and is used for handle and cement dispenser for corner finisher.......... .................. . ..Rental 6" USG Steel Joint Finishing Knife Flat Applicator Corner Roller Applies cement to flat joints preparatory to laying on tape by hand..................................... . . Rental For forming corners.......................... . Rental U. S. Gypsum Company Corner Finisher Z" or 3" To be used with the Corner Applicator for applying fin ish coat of cement over inside corners.......... . Rental Either plain (as shown) or hammer head handle. (Available locally at lumber dealers, hardware or paint stores.) 7" Hand Finisher 10" Hand Finisher Applies first coat of cement over tape leaving cemented area smooth with feathered edges Rental Applies second coat of cement over tape leaving a fin ished joint............................................. . . Rental 12" Hand Finisher Applies third coat of cement over tape leaving a finished joint. May be used instead of 10" hand finisher for second coat if a wider joint is desired ................ Rental 10" USG Steel Joint Finishing Knife U. S. Gypsum Company Plain handle only. (Available locally at lumber dealers, hardware or paint stores.) Hand Pump Universal Pole Sander and Block Sander Broadknife and Pan Cement Mixer Pump with appropriate nozzles is used to fill the Auto matic Taper, Corner Applicator, Flat Applicator and 7" and 10" Hand Finishers . ............................................ Rental Furnished at no additional charge with each set of Hand Finishers......................................................... ... Additional sanders may be purchased if desired. Furnished at no additional charge with the Automatic Taper or Flat Applicator. Additional pans and broad- knives may be purchased if desired. .. Furnished with each set of tools of any type. May be purchased. Mastic Meter Mastic Meter Pump Applies Sheetrock Brand Adhesive to wood framing .. Rental Pump similar to hand pump with special valves and adaptor to fill Mastic Meter........................................... Rental t in PROCEDURE FOR ORDERING AMES TO OLS A. Applicator sends signed rental agreement and check covering first month's rent and deposit to applicable Ames branch office. Succeeding months' rentals paid per rental agreement to applicable branch of Ames Taping Tools, Inc. (Deposits refunded when tools returned to Ames Taping Tools, Inc.) Model A-3 Dry-Wall Adiilsivi: Ai>i>lkaior h:is trigger mechanism that stands rough usage--offers minimum resistance to a large hulk load of adhesive. Rachel rod and precision construction aids even application of adhesive. Barrel is 16" x V/i"--has quarter-turn breech cap. Nozzle has y" orifice, wedged nose. 2'A quart capacity. Weight approximately 8 lbs. (Available from U.S. Gypsum Co.). Alemite Loader Pump Model 7197-L clamps on 5-gal. pail of Sheetrock Brand Adhesive. Eliminates mess and waste of hand and paddle loading methods of A-3 gun (shown above). Standard pipe thread reducer 1" x %" (available from hardware or plumbing supply stores) may be obtained and used for connection of A-3 gun to pump. (Loader pump available from Alemite Co. distributors.) Key *Wallboard Tool & Equipment Company, 1708 Seabright Avenue, Long Beach, California. tGoldblatt Tool Company, 1910 Walnut Street, Kansas City, Missouri. v'Camco Supply Co., Inc., 5833 Outlook, Mission, Kansas. Available from the above companies. 114 Product information BB026 1946 CONTENTS QUALITY CONSTRUCTION ..................................................................... PAGE 116 TYPES OF SHEETROCK WALLBOARD..................................................... 116 y," REGULAR CORE SHEETROCK......................................................... 116 i/2" TAPERED EDGE SHEETROCK ......................................................... 116 %" TAPERED EDGE SHEETROCK........................................................... 116 i/," TAPERED EDGE SHEETROCK........................................................... 116 %" and l/2" BEVELED EDGE SHEETROCK WALLBOARD...................... 117 Vi" and %" INSULATING SHEETROCK...................................... 117 %" WOODGRAINED SHEETROCK ......................................................... 117 %" PANEL SHEETROCK WALLBOARD....................... 117 s/," SHEETROCK FIRECODE 60............................................................. 118 Vi" SHEETROCK FIRECODE 45............................................................. 118 BAXBORD GYPSUM BACKING BOARD............................................. 118 s/,"BAXB0RD FIRECODE 60 ............................................................... 118 W BAXBORD GYPSUM BACKING BOARD........................................... 119 PRODUCT INFORMATION 115 I w vs# SHEETROCK PRODUCTS QUALITY CONSTRUCTION The three top requirements of a wall and ceiling surfacing material are that it be fireproof, that smooth unbroken wall and ceiling surfaces can be obtained with it, and that it can take any type of decoration. Of all the wallboards, only gypsum wallboard meets all three basic requirements. TYPES OF SHEETROCK The long edges of Sheetrock panels are manufactured with various types of edges; tapered, square, beveled, round and "V" T & G shapes. The choice of edges permits a wide variety of decorative effects. Popular preference for smooth unbroken walls and ceilings, however, makes tapered edge Sheetrock the most widely used of these types, as joints can be completely concealed and reinforced with Perf-a-tape Joint System. Plain and Insulating 4' wide Sheetrock are used in a manner requiring the concealment of end joints, and for this reason the 4' wide Sheetrock panels are produced with SMOOTH ENDS. This permits easier and better finishing of wall and ceiling butt end joints. TAPERED EDGE SHEETROCK FIVE-EIGHTHS INCH REGULAR SHEETROCK--For best results in single layer construction use 5/s" regular (plain core) Sheetrock Wallboard. y" regular Sheetrock has all the advantages of other regular Sheetrock prod ucts. It has a number of plus advantages which make it a popular product with builders and drywall applicators. s/%" regular Sheetrock is extra thick-- extra strong; tapered edges, 4' wide and is available in lengths of 8', 10', and 12'. It has increased bracing strength and resistance to racking loads. Its most important use is with ceiling trusses spaced up to 24" o.c. It has greater impact resistance than other boards of lesser thickness and reduced sound transmission. It is fire resistant and although it does not carry a fire resistant rating of one hour, it is an ideal companion product on jobs where s/s" Sheetrock Firecode 60 is used in areas requiring a one hour rating. (See chapter--board application and finishing.) ONE-HALF INCH--Vi" tapered edge Sheetrock Wallboard has for many years been the accepted product for walls and ceilings of single layer con struction and still remains a recommended product for that use. Available lengths: 6', 7', 8', 9', 10', 12', 14'--longer lengths available on special order depending on location. (Sec chapter--board application and finishing.) THREE-EIGHTHS INCH--This product is considered the standard wallboard for remodel and alteration jobs. It differs from Vi" tapered edge Sheetrock Wallboard only in thickness and weight. For ease of handling, it is recom mended that " tapered edge Sheetrock be used for remodel and repair work where the greater strength and rigidity of Vi" board is not required. Available lengths: 6', 7', 8', 9', 10', 12', 14'--longer lengths available on special order depending on location. (See chapter--board application and finishing.) QUARTER-INCH--!4" Sheetrock is a utility gypsum wallboard. Made with tapered edges at most mills it is lightweight and low in cost. Available in 8' and 10' lengths. Joints between panels are treated with Perf-a-tape Joint System. Quarter Inch Sheetrock is excellent for covering old walls and ceilings and for temporary space divisions. It is flexible and can be applied 116 . -'ft-""'*- >- BB026 1947 ,0 almost any curved surface, providing a full range of design possibilities. VVhen used to refinish old walls, trim generally need not be removed. The panels are merely butted against the trim. A small moulding may be used io cover the joint around the door and window openings. (See chapter-- board application and finishing.) THREE EIGHTHS AND ONE-HALF INCH BEVELED EDGE SHEETROCK-- Beveled edge Sheetrock Wallboard is made on special order only for use where the speed and economy of featured rather than concealed joints are desired. The edges are precision beveled and where two panels are placed side by side, a "V" type joint results. When using Beveled Edge Sheetrock Wallboard for vertically paneled walls, care sho-dd be taken to see that all joints in the room form a pleasing pattern. The board should be erected according to a predetermined design. Since all joints must fall on framing members, the framing members must be accurately spaced. To prepare for decoration, only the nail heads need to be concealed with Perf-a-tape Cement. Available lengths: 6', 7', 8', 9', 10' and 12'. Longer lengths manu factured on special order depending on location. Minimum footage require ment on all orders. THREE EIGHTHS, ONE-HALF AND FIVE-EIGHTHS INSULATING SHEET ROCK--Insulating Sheetrock Wallboard has bright aluminum foil lam inated to its back surface. (For details of insulation values, see chapter-- technical data -- "Vapor Barrier Data.") %" and Vi" Tapered Edge Insulating Sheetrock available in 6', 7', 8', 9', 10', 12' lengths--14' and 16' lengths available on special order depending on location. 5/s" Regular Core Tapered Edge Insulating Sheetrock available in 8', 10' and 12' lengths. Vs" Tapered edge Insulating Sheetrock Firecode 60, available in 8', 9', 10' and 12' lengths. THREE-EIGHTHS INCH WOODGRAINED SHEETROCK -- Standard in Te'' thickness with beveled and square edges, Woodgrained Sheetrock is a special predecorated board, combining the many Sheetrock Wallboard advantages with the appearance of the natural grain of wood paneling. Joint treatment and further decoration are not required. A factory applied lacquer helps protect and preserve the finish. Commercial paste and emulsion waxes give a satisfactory finish where applied to the woodgrained surface. Wax should not be applied, however, if subsequent painting is contemplated. Satin finish varnish may be applied without shellac or a sealer being applied first. Predecorated Sheetrock may be painted with oil, resin emulsion or rubber base paint, providing the surface has not been waxed. Matching colored nails are available. Picture mouldings, cove mouldings, chair rails, plate rails, and base assemblies may be of a wide variety commonly used and may be stained to harmonize or contrast with the wallboard. Woodgrained Sheetrock is recommended for use in libraries, dens, hallways, attics and basement rooms, shops, offices, restaurants, clubs, display rooms, etc. It is excellent for lining closets and effects worthwhile economies. Available lengths: 7', 8', 9' and 10'. (See chapter--board application and finishing-- "Application of Predecorated Sheetrock Wallboard.") THREE-EIGHTHS INCH PANEL SHEETROCK--Panel Sheetrock is e" thick, 16'' wide with rounded edges. Panel Sheetrock comes in Plain, Ranch Pine and Striated finish. It may be nailed directly to studs, or wood furring strips. It may also be applied directly over an existing plaster wall or over a base course of Baxbord Gypsum Backing Board or insulation board using Perf-a-tape Cement as an adhesive. The vertical joints become a decorative feature and give a smart panel effect. There are no joints to 117 treat. The Ranch Pine and Striated finishes arc predecorated. Plain Panel Sheetrock will take any decoration. Available lengths: 7', 8', 9' and 10' depending on location. (See chapter--systems--"Panel Siieetrock System.") FIVE-EIGHTHS INCH SHEETROCK FIRECODE 60 WALLBOARD--The core of -la" Sheet hock Firecode 60 is especially formulated to give increased fire resistance to meet requirements of certain more rigid building codes. Parti tions faced both sides, and floor and ceiling construction faced with Siieetrock Firecode 60 have a one-hour fire resistance rating with specific design require ments. Underwriters' Laboratories tested; each bundle bears the Underwriters' Laboratories label. Siieetrock Firecode 60 is especially suited for all requirements for single occupancy units, common walls to attached garages, basement ceilings, utility rooms and ceilings, corridor walls and ceilings, stair halls, column and beam fireproofing, backup for acoustical treatment, walls and ceilings of volatile storage areas, and in other areas where a one-hour fire resistant rating may be required. Available lengths: 8', 9', 10', 12', 14'. (See chapter--technical data--"Fire Resistance Ratings.") ONE-HALF INCH SHEETROCK FIRECODE 45 WALLBOARD--Underwriters' Laboratories rated for 45 minutes fire resistance for partition and floor-ceiling construction. Recommended for use in areas where building codes require a 45 minute fire resistance rating. Each bundle bears the Underwriters' Labora tories label. Available lengths: 8', 9', 10', 12', 14'. (See chapter--technical data--"Fire Resistance Ratings.") BAXBORD PRODUCTS THREE-EIGHTHS INCH BAXBORD--Baxbord Gypsum Backing Board is available in two sizes: 2' x 8' and 4' x 8'. Both sizes have round edges. Plain Baxbord is encased with strong gray paper on both sides. Use Insulating Bax bord with bright aluminum foil laminated to one surface to provide a vapor barrier and reflective insulation where Baxbord is applied to exterior walls and top floor ceilings. (See chapter--systems--"Job Laminated Sheetrock Wallboard--The Double Wall System" and technical data--"Insulation Values''.) 2' x S' Baxbord is available on order only and is primarily recom mended for use with the Sheetrock Wallboard-TRUSSTEEL Stud Partition Sys tem (see chapter--systems--"Sheetrock Wallboard-TRUSSTEEL Stud Partition Systems"). 4' x 8' Baxbord is recommended for the base layer of the Sheet rock Wallboard Double Wall System. (For technical data see chapter--sys tems--"Job Laminated Siieetrock Wallboard, The Double Wall System.") Vs" Baxbord under certain conditions may be used as a base for acoustical tile (see chapter--systems--Page 73). FIVE-EIGHTHS INCH BAXBORD FIRECODE 60--Is" Baxbord Firecode 60 carries the Underwriters' Laboratories approval for a one hour fire resistance rating'for steel joist, concrete floor, and gypsum wallboard ceiling construction when attached to metal "nail-on" channels. Available in 2' x 8' size only, "V" T & G edges encased with strong gray paper on both sides, it is an ideal base for acoustical tile (adhesive or screw-on application). Taped joints are not required to meet the one hour fire ruling. %" Baxbord Firecode 60 is also an extra strong rigid base for acoustical tiles on wood frame construction where extra fire resistance is desired, but where a one hour rating is not required. This product also provides a lining for heater rooms, garages, volatile storage areas. (See chapter--systems; refer to "Sheetrock Wallboard and Baxbord Backing Board Acoustical Tile Base; also see chapter--technical data--"Fire Resistance Ratings.'') '",~r',i '''wry*:*: , BB026 1948 ONE-HALF INCH BAXBORD--Vz" Baxbord Gypsum Backing Board is a low-cost, easy-to-handle gypsum board manufactured in 2' x 8' size only with "V" T & G edges. Plain Baxbord is encased with strong gray paper on both sides. Insulating Baxbord has a bright aluminum foil laminated to one surface to provide a vapor barrier and reflective insulation as in the case of %" Baxbord. Vz" Baxbord may be used as a backup for acoustical tile on ceiling construction or it may be used for a base layer with the USG double wall system. (See chapter--systems--"Job Laminated Sheetrock Wallboard--The Double Wall System"--Page 48; also see chapter-- usntMS--"Vz" Baxbord Gypsum Backing Board" Page 73.) PR00UCT INFORMATION 118 119 MEMORANDUM B[3026 1950 UNITED STATES GYPSUM COMPANY DISTRICT SALES OFFICES Further information about items mentioned in this manual and complete details about all other U.S.G. products are available at offices located in the following cities. ALBANY, N. Y. ALBUQUERQUE, N. MEX. ATLANTA, GA. BALTIMORE, MD. BIRMINGHAM, ALA. BOSTON, MASS. BUFFALO, N. Y. CHARLOTTE, N. C. CHICAGO, ILL. CINCINNATI, O. CLEVELAND, O. DALLAS, TEX. DENVER, COLO. DETROIT, MICH. GRAND RAPIDS, MICH. HAMDEN, CONN. HARRISBURG, PA. HEMPSTEAD, L. L, N. Y. HOUSTON, TEX. INDIANAPOLIS. IND. JACKSONVILLE. FLA. KANSAS CITY, MO. LOS ANGELES. CALIF. LOUISVILLE, N't . MILWAUKEE. WIS. MINNEAPOLIS. MINN. NEWARK. N. J. NEW ORLEANS. LA. NEW YORK. N. 'i OAKLAND, CALIF. OKLAHOMA CITY. OKLA. OMAHA, NEBR. PAS ADEN \. C.\ 1 II PEORI \. ILL. PHILADELPHIA. PA. PHOENIX, ARIZ. PITTSBURGH. PA. PORTLAND. ORE. PROA IDENCE, R. I. RALEIGH. N. C. RICHMOND. VV SACRAMENTO. CALIF. ST. LOUIS. MO. SALT L tki: CM Y. U 1 A It SAN ANTONIO, MX. SAN DIEGO. CAUL. SAN I R ANC ISC O. C A1 IF. SEAT ILL. WASH SS RAC USE. N. Y. \\ ASHING I ON. D. C.