Mastix Butyl Tape

From the Total Cladding and Roofing Technical Library

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Roll of off-white butyl sealant tape standing on its edge against a plain light background

Mastix Butyl Tape

Manufacturer
Marco Industries
Product
Mastix Butyl Tape
Status
Current
Market
United States
Last verified
October 15, 2026

Mastix Butyl Tape

Mastix is a butyl sealing tape from Marco Industries. It is a soft, pliable gum supplied as a roll with a release paper over the adhesive. The tape is trimmable, non-staining and permanently flexible. It joins metal to metal and works as a joint and end lap sealing tape on metal roofing and wall panel work, including sealant repairs and penetration details.

Mastix is rolled out on through-fastened and standing seam panels. It also seals around windows, doors, roof vents, stacks, access doors and other penetration points. The adhesive keeps the roll from telescoping before installation. Applied to a hot metal roofing panel, the tape stays in place with no melting or oozing while the next panel is positioned. Installation needs no tools.

Properties

  • Chemical name: isobutylene.
  • Chemical family: butyl mixture.
  • Appearance: soft, pliable gum.
  • Specific gravity (H2O=1): 1.59-1.64.
  • Volatile (WL)%: 0.
  • Solubility in water: insoluble.
  • Evaporation rate: not applicable.
  • Odor: none.
  • Flash point: >400°F (204°C), Pensky Marten closed cup.
  • Health hazard, flammability hazard and reactivity hazard: 0-Minimal.
  • Non-staining and permanently flexible.

Data sheets and technical documents

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Current files

Archive

Archived files

No older reviewed revisions are archived for this product yet.

Where it is used

  • Joint and end lap sealing on metal roofing and wall panels.
  • Joining metal to metal.
  • Through-fastened panels.
  • Standing seam panels.
  • Around windows and doors.
  • Around roof vents and stacks.
  • Around access doors and other penetration points.

Application

  1. Roll Mastix Butyl Tape out on through-fastened and standing seam panels, removing the release paper to expose the adhesive.
  2. Position the panel over Mastix.
  3. When positioned, press the panel down on Mastix and fasten in place with QuikDrill or QuikGrip fasteners.

Colors and packaging

  • Colors: Q-126 (off-white to gray), Q126BB (black), Q-126-10 (off-white to gray).
  • 3/32 in x 3/8 in x 45 ft: 16 rolls per carton, 30 cartons per pallet.
  • 3/32 in x 1/2 in x 45 ft: 16 rolls per carton, 30 cartons per pallet.
  • 3/32 in x 3/4 in x 45 ft: 16 rolls per carton, 30 cartons per pallet.
  • 3/32 in x 1 in x 45 ft: 12 rolls per carton, 30 cartons per pallet.