BITEC ISA-4T is a value-added product manufactured to meet the typical industry standard of competitive membranes for an APP smooth membrane. It is made from high-quality polymers blended with distilled bitumen. It is a smooth surfaced membrane reinforced with a non-woven polyester mat. It is installed by heat welding to a suitable prepared surface with a roofer's torch. This membrane is recommended for use over most substrates having minimal movement, and should be installed in accordance to good roofing standards. It is recommended, but not required, that a roof coating be applied to the membrane surface.