Which standard must fiber-reinforced gypsum board installed as above-deck roof thermal insulation comply with?

Fiber-reinforced gypsum board, when used as above-deck roof thermal insulation, must comply with ASTM C 1278. This standard specifically pertains to the requirements for gypsum sheathing, which includes fiber-reinforced products, ensuring they meet the necessary performance criteria for structural integrity and fire resistance.

ASTM C 1278 outlines the physical and mechanical properties that are critical for materials used in construction, particularly when they need to maintain their strength and functionality in diverse environmental conditions typical for roofing applications. Compliance with this standard ensures that the product possesses adequate resistance to moisture, fire, and other stresses, thus providing a reliable and safe insulation option for roofing systems.

The other standards mentioned pertain to different aspects of materials or test methods not applicable to fiber-reinforced gypsum board specifically for roofing insulation, which is why they do not fit the context of this question.