CertainTeed's polyester-reinforced, smooth-surfaced, mop-applied, SBS-modified base sheet, Flintlastic® Poly SMS, is both robust and resilient and delivers the benefits of a homogenous roof system when paired with SBS-modified bitumen cap sheets such as Flintlastic® GMS, Flintlastic® FR-P and Flintlastic® Premium FR-P. Many members of the design and specification community prefer multi-layer modified bitumen roof systems constructed with the same polymer-modified material and application methodology for base and/or interply and cap sheets, to optimize stress resistance to the roof system with materials expanding and contracting at the same rate. This 80 mil base sheet is manufactured with a high performance, stress resilient polyester reinforcement with excellent elasticity and recovery. The polyester mat is saturated and coated with an SBS-modified asphalt with elastic, waterproofing properties. Flintlastic® Poly SMS can be mechanically attached but is more commonly mopped...See Morewith hot asphalt or cold adhesive, such as FlintBond® Brush to avoid roof penetrations and allow for extended warranty durations. Reach out to your local CertainTeed Territory Manager to request a sample and demonstration of Flintlastic® Poly SMS Base Sheet. See Less