Butyl rubber and mastic tapes create rock-solid, waterproof seals for HVAC ducts, roofing, and outdoor repairs. These flexible, self-fusing tapes bond tight to metal, wood, and masonry, holding strong through rain, heat, and cold.
Butyl rubber and mastic tapes are the go-to choice when you need a seal that truly holds. Built with a thick, sticky butyl rubber compound, these tapes bond aggressively to metal, wood, masonry, and even irregular or slightly dirty surfaces where ordinary tape gives up. Once applied, they form a flexible, watertight barrier that shrugs off rain, humidity, UV exposure, and swings in temperature.
You'll find butyl mastic tape at the heart of HVAC duct sealing, where foil-faced options like Nashua and Polyken FoilMastic (UL 181B-FX listed) lock down seams and joints on rigid and flexible ductwork. Shurtape's ShurMASTIC line offers the same dependable seal for indoor and outdoor duct systems. Beyond HVAC, these tapes shine on roofing repairs, gutter and flashing seals, RV and marine sealing, and patching leaks on tanks, pipes, and outdoor equipment.
Prefer a rubber-backed option? Self-fusing picks like 3M 2212 Butyl Mastic Tape and Scotch 2228 Rubber Mastic Moisture Sealing Tape press into place and bond to themselves for an airtight, watertight wrap around cables, connectors, and electrical joints. For quick patch jobs, flexible repair tapes from Gorilla, T-REX, Pro Tapes, and ISC X-Flex stretch and conform around curves, corners, and hard-to-reach spots. Need a moldable option instead of a roll? 3M's Butyl Rubber Strip Caulk presses by hand into gaps and voids for a custom seal every time.
Whatever the project, our butyl rubber and mastic tape lineup covers a wide range of thicknesses, widths, and temperature ratings (many performing anywhere from -70°F to 300°F), so you can match the right tape to the job and trust the seal to last.
If you're looking for an adhesive product or tape to do a specific job, try our Advanced Tape Finder. This tool allows you to narrow down your search based on adhesive type, removability, peel adhesion, thickness, and other specifications. You can also visit our Shop by Department page to find the best tapes for your specific application or industry.