Over Gypsum Roof Board

Gypsum roof board is a fiber-reinforced panel used as a cover board in commercial roof assemblies, providing a stable substrate for membrane and coating systems. The GAF coating line includes direct-apply options that bond cleanly to gypsum board without compromising the fire rating or moisture management of the assembly.

For gypsum roof board, the Premium Acrylic HydroStop system with GAF Multi-Purpose Primer is the standard path. Apply primer per the manufacturer spec, then a fabric-embedded base coat, then top coat. Warranty terms (10, 15, or 20 years) depend on coverage rate per square. Factory-direct from a GAF-authorized distributor.