SafeWeld APP Base is a durable smooth surfaced, premium APP (Atactic-Polypropylene) cold adhesive applied membrane. Manufactured with a strong fiberglass mat that is saturated and coated with a premium quality, non-blown asphaltic bitumen and APP resins for a durable, heat resistant, flexible and easily maintainable membrane. It is designed for use as a base sheet or interply sheet in cold applied or heat welded APP modified bitumen roof systems.