TRI-PLY ® APP Smooth Membrane (Formerly Tri-Ply® TP-4) Description Tri-Ply® APP Smooth Membrane is a smooth surface modified bitumen membrane manufactured to stringent GAF specifications. Its core is a strong, resilient, non-woven polyester mat that is coated with weather-resistant APP polymer-modified asphalt. Uses Tri-Ply® APP Smooth Membrane is designed for new roofing and reroofing applications, as well as flashings.
