1.1 This specification covers treated core and nontreated core gypsum sheathing, which is designed to be used as a sheathing on buildings.

Note 1—Specification C 1280 contains application procedures for gypsum sheathing board.

1.2 The values stated in either inch-pound or SI (metric) units are to be regarded separately as the standard. Within the text, the SI units are shown in brackets. The values stated in each system shall be used independently of the other. Values from the two systems shall not be combined.