The Geocel 3300 Polyurethane Roofing Sealant is a single-component, high-performance polyurethane sealant that withstands extreme weather conditions and cures to a flexible weatherproof seal. It will adhere to many materials such as stone, masonry, ceramics, wood, steel, aluminum, asphalt, building paper, BUR, concrete, fiberglass, and vinyl. With it's resistance to extreme weather conditions, Geocel 3300 is permanently flexible and has minimal shrinkage.