Seal Trust™ Flashing Tapes are uncured EPDM rubber with specially formulated butyl mastic used in applications on roofs where pipes, stacks, vents, or corners require flexible flashing products to ensure no water infiltration into the roofing system. Flashing Tape allows molding or slight stretching of the material then slowly cures to form. With superior tack and peel strengths, our butyl mastic remains flexible in harsh conditions and gives a permanent water tight seal. Industry standard roofing membrane cleaners and primers must be used to clean the surfaces before application.