Exterior Gypsum Sheathing is a water-resistant product designed for attachment to exterior side-wall framing as an underlayment for various exterior siding materials such as wood, metal or vinyl siding, masonry veneer, stucco, shingles, etc. The panel is manufactured with a wax-treated, water-resistant core faced with water-repellent paper on both face and back surfaces and long edges. 

Exterior Gypsum Sheathing is available in 1/2" & 5/8" thick, 4' wide square edge product. 5/8" Exterior Gypsum Sheathing has a Type X core, for use in fire rated assemblies.

Gypsum wallboard manufactured by American Gypsum contains no asbestos.