Document pYGnQJz3z1aM2pm292y9zayE

SGP 0002592 SPRAYED UTE ACOUSTIC PIASTER BESTWALL FINISHING PLASTERS BESTWALL LITE ACOUSTIC PLASTER Description: A mill-mixed product, Best-wall L'te Accust.c Plaster is an unusually flexible, decorative, incompusticle sound conditioner for new work or refinishing ce-nrgs .n residential, commercial, or industrial builc rgs. May ce 'eft with natural finish or spray painted accoromg to a 'ect'ons alter it is thoroughly dry. Provides exceptional bond to form a porous sound absorbmg surface. Available White or Ultra-White. Ultra-White crov-aes high light reflection. Designed for machine application; can be applied by hand trowel. Features: L.ght Reflection-- White Ultra-White Sprayed 66% 70% T rowelled 69% 7d% Sound-Absorption--.55 to .60 noise reduction coef'-cert. Fire ftesistance^-Ute Acoustic will rot burn or s-a port combustion. Economy--Versatility provides wide field of low cost ko.s- tic treatment m both new work and remodeling SESTWAU LITE ACOUSTIC PlASTER-wn.re jr u.-tn Anne 3 SGP 0002593 SPECIFICATIONS FOR GYPSUM PLASTERING The following specifications covering machine mixed neat basecoat plasters with a lime putty white coat finish are applicable to a maiority of plaster work. As indicated m Section 2A (Materials) Bestwall offers a full line of plaster materials which work well, applied under the ASA 42 Standard Specifications for Interior Plastering. For more information write the Bestwall Gypsum Co. I. GENERAL PROVISIONS The work includes all labor, materials, services, equipment, and scaffolding required to complete the plastering of the proiect in accordance with the drawings and specifications. (See interior lathing specifications.) J. MATERIALS a. Plastering Materials The plaster materials shall be selected from the following categories and brands as manufactured by Bestwall Gypsum Company and conforming to the current ASTM specifications as noted: Fme Sand having rounded particles uniform in sice (frequently called 'quicksand"), fine Perlite or fine Vermiculite shall not be used. c. Water shall be clean, fresh, potable and free from such amours of mineral and organic substances as wouid affect the set of the plaster. d. Materials. Oelivery of. and Protection All manufactured materials shall be delivered in the ordinal packages, con tainers, or bundles bearing the name o the manufacturer of the brand. Plaster and all cementious materials shall be keot dry until ready to be used: they shall be kept off the ground, under cover, and away from sweating walls and other damp surfaces. Metal goods shall be protected against rusting. ]. BASE COAT PROPORTION Bestwall Gypsum Plaster shall be mixed with sand, oerl.te or vermiculite m the proportion of 100 lbs. of plaster to not more than: BESTWALL Lite Acoustic Plaster b. Aggregates (for use with gypsum plaster) Sand. Perlite, or Verrmcutite shall conform to ASTM Specification C35-57T for use m basecoat plaster. For plastering, the aggregate weight per cu. ft. shall be for sand. 100 lbs: for Perlite and Vermiculite. 7 to 11 lbs. TWO COAT WORK (Double-up Method) Sind Pfpfhte or C`itiic leei Over Gypsum Lath 2' > Over Mjiortrv (eicept muuuiithtc concrete) J THREE COAT WORX Fuji (i. t W;h) oil jver m.isonfy fifnt (set itch) :oj! ->v#r 'nntntf S.'M ? ! ;r v i 'f'lC.' te c *<1 t Alt Second (0io*nj ..in in ii*u ,il the pniouftion* noeot-ed h-ive the pfnudfti.-nn mti '* C.ynum PMsier to n.it imo* ihm 2' .u t qt 'Miiie . )pcitiof'in( used <or both nculch i id co.its ' 's i 5 SGP 0002594 4. MECHANICAL MIXING Material that has practically set shall not be retempered or used. Frozen, caked or lumpy material shall not be used. The mixer shall be cleaned of all set or hardened material before materials for a new batch are loaded. Each batch shall be mixed separately. Materials shall be added while mixer is m continuous operation. Put in the approximate amount of water; if sand is used add approximately half the amount of aggregate (if perlite or vermiculite is used add all the aggregate); add all the plas ter; add the remainder of the sand aggregate: mix to the proper consistency, adding water if necessary; and dump the entire batch and use. Note; The mixer should be flushed with water when used intermittently. S. FINISH COAT PROPORTIONS c. Bestwall Lite Acoustic Plaster shall be mixed with water to the proper consistency. 7. THICKNESS OF PLASTER Plaster shall be of the following thicknesses measured from the lace of plaster base to finished plaster surfaces. Wood or metal grounds or plaster screeds shall be installed to assure such thicknesses: I Metal Lath*, Wire Lath and rh.cfcn* Of P<Htr f'Tcfudtrtf Fmifh Coat <n Laths wirs Fabric ..............................................................mm. ( All other types........................................................ V; mm. Masonry and Concrete Walls........................................ Vs mm. Monolithic Concrete Ceilings ......................................... '/a mm. 'a max. a. Plaster thickness when measured from the back plane of metal lath, exclusive of ribs, shall be Vi" minimum. b. If monolithic concrete ceiling surfaces require more than Vi" of plaster to produce required lines or surfaces, metal lath or wire lath bonding for the plaster shall be attached to the concrete before application of plaster. Where the concrete ceiling surfaces are such as to require the application of an excessive thickness of plaster to produce required lines or surfaces, lath shall be applied over furring secured to the concrete. Wood Grounds shall be furnished and installed by others. Metal Grounds shall be furnished and installed by the (plastering) (lathing) contractor. Plaster Screeds shall be installed by the plastering con tractor. I. PREPARATIONS FOR PLASTERING a. Temperature and Ventilation; When the prevailing jutdoor temperature at the building site is less than 55'F. a uniform temperature of not less than 55'F. shall be continuously maintained in the building for a period of not less than one week prior to the application of plaster, while the plastering is being done, and after the plaster is dry. The heat shall be well distributed in all areas, and deflection or protective screens shall be used to prevent concentrated or uneven heat on plaster areas near the heat source. Products of combustion shall be vented to the outside. Ventilation shall be provided to properly dry the plaster during and subsequent to its application. In glazed buildmgs this shall be accomplished by keeping windows open approxi mately 2" top and bottom (or side-pivoted windows approximately 4") to provide air circulation; and by use of temporary circulators or the air-conditioning system m enclosed areas or buildings lacking openings for natural ventilation. If glazed sash are not in place and the building s subiected to hot, dryj^inds or temperature differentials from day to n-gnt of 20'F. or more, openings shall be screened with cheesecloth or similar materials. b. Masonry Surfaces on which suction must be reduced shall be properly wet down immediately before the piaster s applied. Because bituminous compounds do not provde ideal bases for plaster, the application of plaster to masonry or concrete which has been coated with such compounds s forbidden. c. Monolithic Concrete Surfaces shall be cleaned of ni j-st. loose particles, and other foreign matter. Laitance ml efflorescence shall be removed by washing first with solution of commercial' hydrochloric acid (muriatic ac .!) ml water and then with clean water to remove all traces of ic J. Grease and oil shall be completely removed (Note -^ol Concrete surfaces shall have sufficient roughness to pro- :e proper bond. If necessary, the surface shall be evenly : but not saturated, to provide proper suction if surf >ces me not rough, they shall be hacked or bush hammered -- > -m SGP 0002595 6 I i % i *i i ( i coat of Portland-Cement grout, composed of 1 part of cement to l Vi parts of fine sand mixed to a mush consistency, shall be applied. The Portland-Cement grout shall be forcibly dashed on the concrete surface, using a stiff fiber brush, with a whip ping motion. This coat shall be kept damp for at least two days immediately following its application and then allowed to dry. Before application of plaster, the surface shall be evenly dampened if necessary to provide proper suction. d. Metal Grounds and other accessories, such as corner beads, screeds, picture molds, etc., shall be carefully examined to see that they are straight, curved, plumb, level, square, or true to the acquired angles, as the case may require, before the plaster is applied. e. Surfaces shall be carefully examined before the plaster is applied thereto, and the proper authorities notified of any and all unsatisfactory conditions. Application of the plaster then shall not proceed until such unsr'.isfactory conditions have been satisfactorily remedied or adjusted. S. APPLICATIONS OF 8ASE COAT a. Two-Coat Work.--Base (first) coat shall be applied with sufficient material and pressure to form good bond on gypsum lath or masonry as the case may be, and to cover well. Then, before this scratch coat has set. and without raking its surface, material of the same proportions shall be doubled back to bring the plaster out to grounds, struck to a true surface with rod and darby, and left rough, ready to receive the finish (second) coat. Slow-setting plaster shall be accelerated to pro vide a set (mixed material) of less than 4 hrs. b. Three-Coat Work--Scratch (first) coat shall be applied with sufficient material and pressure to form goad full keys on metal lath, wire lath, or wire fabric, or good bond on gypsum lath or masonry, as the case may be, and to cover well and then be scratched to a rough surface. Slow-setting plaster shall be accelerated to provide a set (mixed material) of less than 4 hrs,. Brown (2nd) coat shall be applied after the scratch (1st) coat has set firm and hard, brought out to grounds, straightened to a true surface with rod and darby, and left rough, ready to receive the finish (3rd) coat. To insure full plaster thickness, plaster screeds should be applied to the scratch coat prior to the application of the brown coat. c. Plastering on Monolithic Concrete-Surfaces of walls and columns shall have a scratch coat of bond plaster, followed by a brown coat of gypsum plaster (in the propertions of 100 lb. of Bestwall Gypsum Plaster to not more than 3 cu. ft. of sand or perlite) troweled mto the scratch coat before it has set. The brown coat shall be brought out to grounds, using a doubleback application if required, straightened to a true surface with rod and darby, and left rough, ready to receive the finish coat. Surfaces of ceilings shall have a coat of bond plaster, scratched m thoroughly, doubled back, and filled out to a true. even surface and leu rough (maximum thickness W). to receive the finish coat. d. 2" Solid Gypsum Lath and Plaster Partitions shall be scratched in on both sides with fast setting plaster (maxi mum 3 hrs.) practically simultaneously. The side away from the temporary bracing shall be browned after both scratch coats have set and practically dried. After this brown coat has set firmly, remove the braces and brown the other side leaving 1/16" for finish coat to bring wall to full 2" thicknfess. 10. APPLICATION OF FINISHES The finish coat shall be applied to a partially dry base coat or to a thoroughly dry base coat which has been evenly wetted by brushing or spraying. The use of excessive water shall be avoided in the application of all types of finish coat plastering. a. Trowel Finishes Gypsum Lime Putty Trowel Finish shall be applied over the base coat scratched in thoroughly, laid on well, doubled back and filled out to a true, even surface. The general thick ness shall be 1/16" to Vs". The finish shall be allowed to draw a few minutes and then it Shall be well-trowelled with water to a smooth finish, free from cat faces and other blemish, s or irregularities. b. Float Finishes Float finishes shall be applied over the base coat, scratched in thoroughly, laid on with a trowel to an even surface, and then floated (with wood, carpet, cork, rubber or other type floats, depending on the texture desired) to a true, even sur face free from slick spots or other blemishes. c. Acoustical Plaster and Other Special Plasters: 1. Bestwall Lite Acoustic (White) Plaster shall be mixed with clean water only (or machine or trowel application over gypsum basecoat plaster, monolithic concrete and other surfaces which are firm, clean and free of efflorescence or water soluble sub stances. Gypsum basecoats should be half dry to dry. Con^ete should be dry. Spray--For first coat use 55 to 60 qts. of water per 40 lb bag. Apply thick. Level with darby and allow to dry before apply ing finish coat. For finish coat use 5 to 10 additional qts. of water per bag depending upon texture desired. When applied over low suction bases, the material should be apolied in three applications, the first application furnishing the suction for subsequent coats. Any large fissures in the first coat should be filled and leveled before applying the finish coat. Hand--Use 50 to 60 qts. of water per 40 lb. bjg for both basecoat and finish coat. Apply basecoat V th.cx, allow to dry. then apply finish coat Vg" thick. Trowel fm.sn may be smooth troweledjloated,stippled.or darbied alter it Sas takenup sufficiently. Ultra-White Finish--Where a light reflection of 'O 'i or more is desired with machine application use Bestwall L.te Acoustic Ultra White Piaster for the finish coat only. 2. Special Plasters shall be applied m accor : jr-ce with the directions of the Manufacturer. SGP 0002596 7 SGP 0002597 BESTWALL GYPSUM COMPANY . Ardmore, Pennsylvania Plants and offices throughout the United S