Torchflex TP-HD-Cap Heat Welded Cap Sheet is constructed with a tough composite reinforcement of non-woven polyester strengthened with a glass fiber scrim in both machine and cross directions. The composite reinforcement imparts tremendous strength as well as excellent dimensional stability both before and after application. The mat layer of Torchflex TP-HD-Cap is coated top and bottom with select SBS polymers and premium quality asphalt to an approximate thickness of 4.0 mm (158 mils). Ceramic coated mineral granules also are embedded in the surface of the product to provide protection against ultraviolet radiation. A light micro-perforated film is bonded to the underside and conveniently disappears upon heat welding. Torchflex TP-HD-Cap is meant to serve as the top ply in a two-ply SBS modified bitumen system.