CertainTeed's workhorse granulated, mop-applied, SBS-modified bitumen cap sheet, Flintlastic® GMS, is valued for its high elasticity and decades of consistent quality. This 145 mil membrane is manufactured with a resilient polyester reinforcement, offering exceptional durability and resistance to weathering. GMS is available in three true-blend colors designed to complement popular shingles. Face it - some old dogs don’t need new tricks, and CertainTeed hot asphalt and cold adhesive low-slope roof systems have consistently delivered on the promise of protection for generations. These systems offer multiple watertight layers with unparalleled bond strength. So when the risk of a roof leak means more than just a maintenance nuisance, trust what works and spend the time to install peace-of-mind. Reach out to your local CertainTeed Territory Manager to request a sample and demonstration of Flintlastic® GMS.