April 04, 2018

Creating Imus Seal® Butyl Joist Tape, the ultimate deck flashing tape.

Joist and beam tapes for deck flashing including Imus Seal Butyl Joist Tape, Trex Protect, Nichigo G-Tape 3040BK, DeckWise WiseWrap JoistTape, Cofair Products Deck Flash Barrier, and Grace Vycor Deck Protector

It is becoming increasingly common for contractors and DIYers to use a peel-and-stick flashing membrane to protect the top of joists and beams along with the ledger, posts, and stair stringers when framing a deck. Flashing tape products help extend the life of the deck structure by diverting water and sealing areas where decking fasteners are installed, helping keep the wood dry and decreasing the risk of water damage and rot.

Deck construction with Imus Seal Butyl Joist Tape flashing

In a Professional Deck Builder article, Scott Gibson wrote, "The ideal flashing should not only resist corrosion, but also hold up in sunlight, install easily, and cost a reasonable amount".1 When developing our joist tape product, we challenged ourselves to create the ultimate deck flashing tape.

  • Composition
    Butyl rubber has many advantages over other adhesives like rubberized asphalt (bitumen), including longer-lasting stickiness, less staining, less high-temperature oozing, and a wider temperature range.2 Butyl also lacks the harmful volatile organic compounds (VOCs) found in other products.
  • Tear Resistance and Thickness
    Thin, easy to tear flashing tapes have questionable long-term durability. Thick and heavy flashing tapes are often difficult to form.
  • Size
    A joist tape should be easy to install on common sizes of framing boards with little overlap or trimming need.
  • Price
    It should not cost a fortune to protect your deck structure™.

The product we came up with, Imus Seal Butyl Joist Tape, has a high-performance butyl adhesive, the ideal thickness for strength and durability, and is available in several sizes. The comparison table below shows why Imus Seal Butyl Joist Tape stands out among deck flashing tapes.

Imus Seal
Butyl Joist Tape
Nichigo G-Tape
WiseWrap JoistTape
Deck Flash Barrier
Vycor Deck Protector
Composition Butyl Butyl Acrylic Asphalt Asphalt Asphalt
Zero VOCs
Tear Resistant
Thickness 20 mil 20 mil 8.7 mil 35-40 mil 25 mil
Size 1-5/8” x 50’
4” x 50’
6” x 50’
1-5/8” x 50’
3-1/8” x 50’
2” x 65’
4” x 65’
6” x 65’
3" x 75'
12” x 25’
3" x 75'
12” x 25’
4" x 75'
6" x 75'

Imus Seal Butyl Joist Tape installed on deck joists

1 Beyond Aluminum Flashing | Professional Deck Builder
2 Flexible Flashing | HomeAdvisor Pro