Which statement best describes Class 'A' fire-resistance rating for roofing per ASTM E 108?

• A. A rating indicating roofing can withstand no exposure to fire.
• B. A moderate exposure rating used only for metal roofs.
• C. The highest fire-resistance rating for roofing per ASTM E 108 indicating roofing is able to withstand severe exposure to fire originating from sources outside the building.
• D. A temporary rating while testing is conducted.

Answer: (C)

Class A fire-resistance rating is about how well a roof covering can stand up to severe external fire exposure in standardized tests. It is the highest rating available for roofing under ASTM E108, meaning the roofing assembly can resist the most intense fire exposure from sources outside the building. This reflects exterior fire performance, not a guarantee of no exposure or internal fire behavior. The other statements describe no exposure, only moderate exposure, or a temporary testing status, none of which align with the official Class A designation under ASTM E108.