Henry 885 Tropi-Cool 100% Silicone Wet Patch Roof Leak Repair Sealant is a high solids dispersion of 100% silicone. It stops leaks instantly on wet or dry surfaces. It offers excellent UV resistance and weathering performance with no hardening, chalking, crazing, or cracking, and is mold and mildew resistant. It also offers excellent adhesion to a wide variety of building materials.