Products / Sharkskin 2-Ply System

The Sharkskin 2-Ply System is Kirsch Building Products' patented two-layer roof underlayment system: an engineered high-tensile polypropylene-based sheet nailed to the deck as an anchor sheet, with a second layer of identical structure bonded to it by a synthetic butyl adhesive, marketed as outperforming 30-lb asphalt felt and asphalt-based adhesive underlayments and aimed at high-velocity hurricane zones. The anchor and cap sheets are specified with the Sharkskin Ultra and Sharkskin Ultra SA architectural specifications, and the product page links a Miami-Dade Notice of Acceptance. The system's limited warranty runs 50 years from installation for use beneath concrete or clay tile, metal, slate and asphalt fiberglass shingles, and is void if the system is left uncovered for more than one year.