Rolled Mastic
What exactly is rolled mastic…?
Rolled Mastic is the equivalent of liquid duct sealant but on a roll. Sitting on a shelf it might appear as an oversized roll of the aluminum foil red letter tape—it looks like aluminum foil tape even when it’s installed. But this product is more like Duct Sealant than Duct Tape. The Metallic Backing is a Red letter Aluminum Foil that provides electrical protection and meets UL-723 for Smoke and Flame approval, the other side is the sticky side: a butyl adhesive that acts as the sealant once the middle film is removed during install.
Mechanical contractors specializing in commercial work typically use a bucket and brush, but they keep a small stock of the rolled mastic for those jobs that require an immediate tack as well. Often times on Rooftop Ductwork, the contractor will use either this product or the Hardcast 404 solvent based liquid duct sealant in a bucket. They both provide the immediate tack and instant seal required in exposed applications that have temperature variations or an unexpected rain shower. Other times it’s when a system is being pressure tested and the Mastic Tape is used over the existing liquid mastic to determine the location of the leaks while the system is running.
- Sometimes the HVAC Contractor wants to start sealing the Duct on a job that has yet to have the Roof on yet. For these applications the Rolled Mastic provides this immediate tack that’s not affected by rain or temperature
- Rolled Mastic has a peel away strippable film, with butyl adhesive on the sticky side. Commercial contractors would liken it to a very thin layer of the standard 440 used when connecting rectangular duct sections to one another.
What contractors should know…
- Rolled mastic is typically 2” or 3” wide on a 100-ft roll
- Rolled sealant is a Hardcast Duct Sealant just like the DS321, the CCW181 and even the 404 solvent based Sure-Grip all of which come in a bucket
- One gallon of liquid duct sealant has a coverage of about 320 Linear Feet using a 3” wide application and a Rolled Mastic is, of course, 100 ft of coverage
- Cost on liquid water based averages $15.00 USD gallon, liquid solvent based 27.00 gallon and 3” x 100 ft rolled mastic 30.00 per roll
- Consistent 17 mils layer of rolled mastic means that the application will be consistent where as a bucket and brush leaves it entirely to the applicator
- Rolled mastic is cleaner; liquid mastic is messy; using a brush makes it even messier
- Most contractors don’t use the entire bucket and never scrape the edges to get every last bit. With a roll, every inch can be used
- Contractors can actually precut the Rolled Mastic to the strips required on the 4 sides of rectangular duct with Slip and Drive connections much like they do with the slips and drives themselves
- Rolled Mastics have no VOC’s
- Hardcast 1402 and 701 are used on commercial jobs. Both are UL Listed for Smoke and Flame. The 701 was developed as a Roofing tape and has thicker amount of butyl
- 1403 and 1404 are basically the same Rolled Mastic. Both are created specifically for residential and have the UL181 Listing lettered on the backing
- Tearing easily is a plus—the 1402 and the 1404 tear easily which means they are easier to work with
- 3” 1402 is , by far , the biggest selling of all types and widths used in both commercial and residential applications
- Sample rolls of 32 ft Rolled Mastic are available upon request
