Type X drywall achieves fire resistance primarily due to which feature?

Type X drywall achieves fire resistance primarily due to which feature?

• A. Foil backing
• B. Fire resistant core additives
• C. Exterior use rating
• D. Waterproof coating

Answer: (B)

Fire resistance for Type X drywall comes from its fire resistant core additives. The gypsum core is reinforced with mineral fibers and other additives that slow heat transfer and help maintain structural integrity when exposed to high temperatures. As heat is applied, the gypsum releases water and the additives work to form a protective layer, delaying flame spread and collapse longer than standard drywall. This makes the board inherently more fire-resistant, regardless of surface coatings or exterior ratings. Foil backing, while it can act as a radiant barrier in some assemblies, is not what gives Type X its primary fire rating. Exterior use ratings and waterproof coatings address weather exposure and moisture resistance, not the material’s fire resistance.

Fire resistance for Type X drywall comes from its fire resistant core additives. The gypsum core is reinforced with mineral fibers and other additives that slow heat transfer and help maintain structural integrity when exposed to high temperatures. As heat is applied, the gypsum releases water and the additives work to form a protective layer, delaying flame spread and collapse longer than standard drywall. This makes the board inherently more fire-resistant, regardless of surface coatings or exterior ratings.

Foil backing, while it can act as a radiant barrier in some assemblies, is not what gives Type X its primary fire rating. Exterior use ratings and waterproof coatings address weather exposure and moisture resistance, not the material’s fire resistance.