Products / Sharkskin Comp

Sharkskin Comp is Kirsch Building Products' mechanically-attached synthetic roof underlayment for fiberglass-based asphalt shingle, modified-bitumen composite shingle and metal roof installations. It consists of a woven polypropylene scrim base layer with a top polyolefin coating and a nonwoven polyolefin slip-resistant surface, gray with red printing, at a nominal weight of 3.8 lb per 100 sq ft (a 10-square roll weighs 40 lb per its own CSI spec). It is fastened with standard EG roofing nails or a hammer-tacker with staples, needs no cap nails, and the manufacturer rates it for up to 6 months of UV exposure and a 25-year warranty. ICC-ES ESR-1708 lists Sharkskin Comp as an alternative to ASTM D226 Type I and Type II felt under the 2006-2018 IBC/IRC and requires mechanical attachment with corrosion-resistant fasteners at minimum 3-inch head laps and 6-inch end laps.