ASTM C 840:2025

1.1 This specification covers the minimum requirements for the methods of application and finishing of gypsum board, including related items and accessories to interior walls and ceilings and to exterior soffits. 1.2 Details of construction 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. 1.2.1 Where this specification is more stringent (size or thickness of framing: size and spacing of fasteners) than the fire-rated construction, this specification shall govern. 1.3 Where sound control is required for a gypsum board assembly, details of construction shall be in accordance with reports of acoustical tests of assemblies that have met the required acoustical values. 1.4 Unheated spaces above gypsum board ceilings shall be properly ventilated (see Appendix X2 ). 1.5 The various application systems are located in the following sections: I Application of Single-ply Gypsum Board to Wood Framing Members 8 II Application of Two-ply Gypsum Board to Wood Framing Members 9 III Application of Gypsum Board by Adhesive Nail-on to Wood Framing Members 10 IV Semi-solid Gypsum Board Partitions 11 V Solid Gypsum Board Partitions 12 VI Application of Gypsum Board with Adhesives to Interior Masonry or Concrete Walls 13 VII Application of Gypsum Board to Rigid Foam Insulation 14 VIII Application of Gypsum Board to Steel Framing and Furring 15 IX Arches and Bending Radii 16 X Application of Gypsum Board to Receive Tile by Adhesive Application 17 XI Application of Exterior Gypsum Soffit Board or Other Gypsum Board for Use in Exterior Soffits 18 XII Floating Interior Angles 19 XIII Control (Expansion) Joints 20 XIV Foil-backed Gypsum Board 21 XV Application of Vinyl Faced Gypsum Board 22 1.6 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.7 The text of this specification references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the specification. 1.8 The following precautionary caveat pertains only to Sections 6 - 26 . This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see 4.1.1 , 4.1.2 , and 24.5 . 1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

91.100.10