PermaPly 28 Base Sheet is designed for use as the first or base sheet in built up roofing or modified bitumen roof assemblies. The Asphalt coating makes it suitable as an intermediate or ply felt in cold-applied built-up and modified bitumen roof assemblies. It is exceptionally pliable, easy to handle and lays flat. Fiber Glass Reinforcement Mat provides low moisture, excellent dimensional stability and resistance to rot make it an ideal replacement for organic base or ply sheets. It also provides a solid dimensionally stable substrate for other roofing membrane components.