ASTM C840-20 Standard Specification for Application and Finishing of Gypsum Board, 2020
This specification covers requirements for the methods of application and finishing of gypsum board. Construction details for a specific assembly to achieve the required fire resistance shall be obtained from reports of fire-resistance tests, engineering evaluations, or listings from recognized fire testing laboratories. Gypsum board assembly shall conform to acoustical tests of the specification where sound control is required. Moreover, gypsum assembly shall conform to framing size, fasteners spacing, ventilation, substrate, surface preparation, cutting, and installation application as indicated in the specification. Materials categorized under this specification include: gypsum boards, gypsum wallboards, gypsum backing board and coreboard, water-resistant gypsum backing board, exterior gypsum soffit board, and gypsum ceiling board. Finishing materials include: compounds, joint tape, fasteners, nails, screws, and staples. A fire test of assemblies shall be conducted to determine a fire resistance rating required for gypsum board assembly. Gypsum board shall be cut by scoring and breaking or by sawing, working from the face side. Masonry or concrete walls shall be dry, free of dust, oil, or form release agents, protrusions or voids, or foreign matter that inhibit bond for adhesively applied gypsum board. All materials shall be kept dry. Where gypsum board is stored outside, it shall be off the ground, properly supported on a level platform and fully protected from the weather or direct sunlight exposure.