Henry 204 Plastic Roof Cement is a premium, trowel-grade sealant used for dry surfaces, which makes it ideal for filling flashing pans around roof penetrations. It is made from high-quality refined asphalt and is heavy-bodied for smooth spreading in cold weather. Henry 204 Plastic Roof Cement forms a tough, long-lasting flexible film that won't become brittle and crack in the coldest weather, run and sag in the hottest.