CertainTeed Flintlastic® Poly SMS Base Sheet is designed for use as a base sheet for both hot and cold applied, modified or built-up roofing systems. It is suitable for use in the construction of various types of membranes for both new construction and reroofing, over a variety of substrates. Flintlastic Poly SMS Base Sheet will provide additional strength when used as a first ply over nailable, non-nailable and insulated substrates. In addition, it will perform as a venting base sheet when spot mopped over plastic foam type insulations. Also suitable as a mid ply in multi-layer systems.