Standard Specification for Application and Finishing of ...

1 Designation: C 840 08 Standard Specification forApplication and Finishing of Gypsum Board1 This Standard is issued under the fixed designation C 840; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon ( ) indicates an editorial change since the last revision or Standard has been approved for use by agencies of the Department of Scope* This specification covers the minimum requirements forthe methods of Application and Finishing of gypsum board,including related items and Details of construction for a specific assembly toachieve the required fire resistance shall be obtained fromreports of fire-resistance tests, engineering evaluations, orlistings from recognized fire testing Where this specification is more stringent (size orthickness of framing.)

2 Size and spacing of fasteners) than thefire-rated construction, this specification shall Where sound control is required for a gypsum boardassembly, details of construction shall be in accordance withreports of acoustical tests of assemblies that have met therequired acoustical Unheated spaces above gypsum board ceilings shall beproperly ventilated (seeAppendix X2). The various Application systems are located in thefollowing sections:IApplication of Single-Ply Gypsum Board to Wood FramingMembers8 IIApplication of Two-Ply Gypsum Board to Wood FramingMembers9 IIIA pplication of Gypsum Board by Adhesive Nail-On toWood Framing Members10 IVSemi-Solid Gypsum Board Partitions11 VSolid Gypsum Board Partitions12 VIApplication of Gypsum Board with Adhesives to InteriorMasonry or Concrete Walls13 VIIA pplication of Gypsum Board to Rigid Foam Insulation14 VIII Application of Gypsum Board to Steel Framing and Furring15 IXArches and Bending Radii16 XApplication of Gypsum Board to Receive Tile byAdhesive Application17 XIExterior Application of Gypsum Wallboard andExterior Gypsum Soffit Board18 XIIF loating Interior Angles19 XIII Control (Expansion)

3 Joints20 XIV Foil-Backed Gypsum Board21 The values stated in inch-pound units are to be regarded asstandard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered The text of this specification references notes andfootnotes which provide explanatory material. These notes andfootnotes (excluding those in tables and figures) shall not beconsidered as requirements of the The following precautionary caveat pertains only Standard does not purport to address all ofthe safety concerns, if any, associated with its use. It is theresponsibility of the user of this Standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to For specific precautionary statements, , , Referenced standards .

4 2C11 Terminology Relating to Gypsum and Related Build-ing Materials and SystemsC 475/C 475 MSpecification for joint Compound and JointTape for Finishing Gypsum BoardC 514 Specification for Nails for the Application of Gyp-sum BoardC 557 Specification for Adhesives for Fastening GypsumWallboard to Wood FramingC 645 Specification for Nonstructural Steel Framing Mem-bersC 754 Specification for Installation of Steel Framing Mem-bers to Receive Screw-Attached Gypsum Panel ProductsC 920 Specification for Elastomeric joint SealantsC 954 Specification for Steel Drill Screws for the Applica-tion of Gypsum Panel Products or Metal Plaster Bases toSteel Studs from in. ( mm) to in. ( ) in ThicknessC 1002 Specification for Steel Self-Piercing TappingScrews for the Application of Gypsum Panel Products or1 This specification is under the jurisdiction of ASTM Committee C11 onGypsum and Related Building Materials and Systems and is the direct responsibilityof Subcommittee on Specifications for the Application of Gypsum and OtherProducts in edition approved May 1, 2008.

5 Published June 2008. Originallyapproved in 1979. Last previous edition approved in 2007 as C 840 referenced ASTM standards , visit the ASTM website, , orcontact ASTM Customer Service at ForAnnual Book of ASTMS tandardsvolume information, refer to the Standard s Document Summary page onthe ASTM *A Summary of Changes section appears at the end of this ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United by ASTM Int'l (all rights reserved); Fri Sep 19 11:15:17 EDT 2008 Downloaded/printed byTerry Kastner (Northwest Wall and Ceiling Bureau) pursuant to License Agreement. No further reproductions Plaster Bases to Wood Studs or Steel StudsC 1007 Specification for Installation of Load Bearing(Transverse and Axial) Steel Studs and Related Accesso-riesC 1047 Specification for Accessories for Gypsum Wall-board and Gypsum Veneer BaseC 1396/C 1396 MSpecification for Gypsum BoardC 1546 Guide for Installation of Gypsum Products in Con-cealed Radiant Ceiling Heating Department of Commerce Publication:PS20 American Softwood Lumber Standard :ANSI A Adhesives for Installation of Ce-ramic Tile, Type I and Type II43.

6 Definitions shall be in accordance of Terms Specific to This compound,n a compound formulatedand manufactured to serve as a taping or Finishing compound,or lighting,n a condition where interior sur-faces are flooded by natural or artificial lighting at an ,n paint (including primers), texture,coatings, and coverings such as wallpaper and sheet plasticmaterials designed to conceal or protect the surface of thegypsum board (seeAppendix X3). type,n a compound in powder form to be mixedwith water before type,n a compound that hardens by theevaporation of the vehicle used to make the primer,n a paint material specifically for-mulated to fill the pores and minimize the suction differencebetween gypsum board surface paper and the compound usedon finished joints, angles, fastener heads and accessories, andover skim panel,n outside ply of multiple layer gypsumboard wallboard,n wallboard that has had thejoints taped, has had the joints, fastener heads, and flanges ofaccessories concealed with joint compound, and has beensanded to prepare the surface to receive job applied ,n the preparation of gypsum board sur-faces to receive the field Application of compound (sometimes called topping com-pound)

7 ,n a compound used for successive coats over thetaping or all-purpose compound that provides a smooth andlevel surface for the Application of of accessories,n the Application of com-pound to flanges of accessories to create a monolithic ,n that part of an accessory extending overthe face of the gypsum wallboard intended to become a part ofthe monolithic plane of the prepared member,n that portion of the framing,furring, and blocking to which the gypsum board is ,v a condition reached when the compoundhas lost its plasticity to an arbitrary degree, measured inresistance to penetration or photographing,n a condition where the fin-ished joint areas visible after final tape,n a strip of material designed to beembedded in compound to reinforce joints, cracks, or othersmall openings in or between gypsum treatment,n Application of joint tape andcompound to the joint between gypsum compound,n a compound (abrasive)used to adhere gypsum board to gypsum board or othermonolithic contact,n the edges and ends are buttedat joints but not forced Small gaps not greater than1 4in.

8 (6mm) are acceptable ( ) or vertical Application ,n gypsum boardapplied with the edges parallel to the framing member to whichit is or horizontal Application ,n gypsumboard Application with the edges applied at right angles to theframing member to which it is type,n a factory-prepared compoundready to be used without the addition of ,adj pertaining to a mandatory obligationimposed by a force outside this Standard , such as a buildingcode, project specification, contract, or purchase type,n a compound that hardens by achemical reaction and increases in straight through coat,n a thin layer of skim coat compoundapplied over the entire surface of finished gypsum A skim coat is essentially a film ofjoint compound and is not applied at a readily measurablethickness. There is no specific mil thickness that constitutes aproper skim coat (SeeAppendix X8).

9 Coat compound,n joint compound, or a ma-terial specifically formulated and manufactured for use as askim ,adj pertaining to a mandatory require-ment of this Standard or a referenced requirement ( ). fastener heads,n the Application of com-pound to cover the fastener head to create a monolithic compound (sometimes called embedding com-pound),n a compound used for embedding and bonding jointtape and for the first coat over the heads of fasteners andflanges of of joints,n the Application of compound andjoint reinforcing tape to the joints between adjoining joint ,n a joint between gypsum boards thathas been covered with joint tape and joint compound asspecified , , Strip moldings or similar devicesshall be from Government Printing Office, Washington, DC from American National standards Institute (ANSI), 25 W.

10 43rd St.,4th Floor, New York, NY 10036, 082 Copyright by ASTM Int'l (all rights reserved); Fri Sep 19 11:15:17 EDT 2008 Downloaded/printed byTerry Kastner (Northwest Wall and Ceiling Bureau) pursuant to License Agreement. No further reproductions Environmental of Gypsum Board, joint Treatment Materi-als, and Adhesives Room temperature shall be maintained atnot less than 40 F (4 C) during Application of gypsum boardexcept when adhesive is used for the attachment of gypsumboard. For the bonding of adhesive, joint treatment, texturing,and decoration, the room temperature shall be maintained atnot less than 50 F (10 C) for 48 h prior to Application andcontinuously thereafter until completely When a temporary heat source is used, the temperatureshall not exceed 95 F (35 C) in any given room or Adequate ventilation shall be maintained in the work-ing area during installation and curing Gypsum board shall be protected from direct exposureto rain, snow, sunlight, or other excessive weather Where manufacturers recommendations differ from theabove, follow their Ready-mixed joint compounds shall be protected fromfreezing, exposure to extreme heat, and direct Materials and Boards A family of gypsum sheet products asdefined in X (Special Fire-Resistant)