SMARTFAB™ Polyester Reinforcement is engineered for use with SMARTCOAT™ liquid applied roofing systems and SmartFlash ONE flashing or repair. SMARTFAB 500 (Heavy Soft) (Tietex T272 or Equal) is valued for resilience and conformity. #500 has superior strength and elongation properties, resulting in excellent resilience to stress caused by rooftop thermal expansion and contraction. It provides good conformability on smooth or semi-smooth surfaces such as cap sheet, smooth surface and filled or spudded gravel, and irregular shapes. SMARTFAB 501 (Firm) (Tietex T326 or Equal) is a stitch bonded polyester fabric with a firm finish valued for strength and lay-flat handling when used as a full field reinforcement in SMARTCOAT liquid applied roofing systems. It has fewer stiches per inch than SMARTFAB 500, which allows for better wettability and less brooming. SMARTFAB 501 has excellent tear strength, puncture resistance, and tensile and elongation, delivering best-in-class resilience to...See More rooftop stress and thermal movement. It provides good conformability on smooth or semi-smooth surfaces such as cap sheets, and conforms to irregular shapes. Reach out to your local CertainTeed Territory Manager to request a sample of SMARTFAB and training on the SMARTCOAT Liquid-Applied Roof Restoration system or SmartFlash ONE flashing and repair resin. See Less