April 04, 2018

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

Installing joist tape can be more time consuming and labor intensive than using a joist cap such as Imus Cap, but the versatility and lower cost of joist flashing tape products makes their use attractive to contractors and DIYers.

Imus Seal on deck

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 we decided to add a joist tape product to our offering, we challenged ourselves to create the ultimate deck flashing tape.

  • Butyl Composition
    Butyl rubber has many advantages over other adhesives 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 Resistant
    Thin, easy to tear flashing tapes have questionable long-term durability. Thick and heavy flashing tapes are often difficult to form.
  • Thoughtful Roll Sizes
    A joist tape should be easy to install on common sizes of framing boards with little overlap or trimming need.
  • Great Price
    It should not cost a fortune to keep your deck structure dry.

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

Deck flashing joist and beam tapes including Imus Seal, Trex Protect, Nichigo G-Tape 3040BK, DeckWise WiseWrap JoistTape, Cofair Products Deck Flash Barrier, and Grace Vycor Deck Protector
Imus Seal Trex Protect Nichigo G-Tape 3040BK DeckWise WiseWrap JoistTape & LedgerTape Cofair Products Deck Flash Barrier Grace Vycor Deck Protector
Composition Butyl Butyl Acrylic Asphalt Asphalt Asphalt
Zero VOCs
AAMA 711
Tear Resistant
Thickness 20 mil 20 mil 8.7 mil 35-40 mil 25 mil
Roll 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'
Price from $18.99 from $28.50* from $18.29** from $34.95* from $22.19* from $29.89*
Buy Now

* Price from Amazon on 10/29/2018
** Price from GTapes USA on 10/29/2018


Featured Product


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