DuraFlex 90TG SBS Base is a tough smooth surfaced, premium SBS (Styrene-Butadiene-Styrene) torch applied membrane. Manufactured with a fiberglass mat that is saturated and coated with high quality, asphaltic bitumen and SBS elastomers for a durable, flexible and easily maintainable membrane. It is designed for use as a base sheet or interply sheet in modified bitumen torch applied roof systems.