ASTM C 1280:2025

1.1 This specification covers the minimum requirements for and methods of application of exterior gypsum panel products that are specifically designed for use as a substrate for exterior cladding. 1.1.1 This specification does not cover gypsum panel products that are specifically designed for interior applications. 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 This specification shall govern where it is more stringent (size or thickness of framing and size and spacing of fasteners) than the fire-rated construction. 1.3 Where sound control is required for a gypsum panel product assembly, the details of construction shall be in accordance with the acoustical test report of an assembly that has met the required acoustical value(s). 1.3.1 This specification shall govern where it is more stringent (size or thickness of framing and size and spacing of fasteners) than the sound-rated construction. 1.4 Where resistance to racking loads or shear is required for a gypsum panel product assembly, the details of construction shall be in accordance with the racking or shear test report of an assembly that has met the required racking or shear value(s). 1.4.1 This specification shall govern where it is more stringent (size or thickness of framing and size and spacing of fasteners) than the racking or shear-tested construction. 1.5 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. 1.6 The text of this standard references notes which provide explanatory material. These notes shall not be considered as requirements of the standard. 1.7 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. 1.8 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.

91.060.10, 91.100.10