LayfastSBS is a superior and competitively priced alternative to traditional 30 & 40 lb organic felt. The addition of SBS rubber to asphalt gives Layfast an electrometric property that is not available in common felt. Layfast SBS contains a higher percentage of asphalt for increased waterproofing. Its inorganic fiberglass reinforcement eliminates the rot and deterioration associated with saturated felt.
It is available in three weights, 35-43-70 lbs/square. It can be used in lieu of 30 & 40 # felt as an underlayment under shingle, tile, and metal roofs.
It is ICC (formerly ICBO) approved and complies with ASTM D226 standards, which most tile, shingle, and metal manufacturers require.