RUBEROID MOP SMOOTH 1.5 membrane is a tough, resilient modified bitumen membrane manufactured to stringent GAF specifications. Its core is a strong, resilient, non-woven polyester mat that is coated with flexible, SBS polymer-modified asphalt and is smooth surfaced. Smooth surfaced mop applied installations must be protected with surfacing. RUBEROID MOP SMOOTH 1.5 Membrane is designed for new roofing and reroofing applications as well as the construction of flashings. RUBEROID MOP SMOOTH 1.5 Membrane is also an ideal product for repairs of built-up roofing membranes or other modified bitumen systems.