WiseWrap® JoistTape
Butyl Membrane Tape

Joist tape is an essential component of a well-built deck! WiseWrap® JoistTape™ Butyl joist barrier tape is a self-adhering protective waterproof membrane engineered to protect joists under the decking boards from premature wood rot, decay, and corrosion. JoistTape™ Butyl deck flash barrier features a high-performance butyl hybrid adhesive with a high strength nonslip polypropylene backing. Butyl joist barrier tape will self-seal around deck screws, nails and fasteners to prevent water infiltration, wood rot and lumber breakdown.

Butyl joist tape is less temperature-sensitive for installation with a low range approximately 25F. This extends the building season in colder climates or at elevation and allows it to start earlier. It maintains its stickiness at much lower temperatures than non-butyl barrier tape. Meaning, application of the tape can be done at colder temperatures. Easily apply to decking joists, around deck support posts and over ledger boards.

Available in 20-22 mil 1-5/8" x 50' and 3-1/8" x 50' rolls.

Coverage Calculator  

Enter Total Linear Feet of Deck Framing:

DeckWise Joist Tape deck barrier flashing material

Waterproof Barrier Protection

Water leakage through your decking boards can cause hidden damage unless your bearers and joists are covered. Even tiny cracks around screws can lead to timber rot. For a small cost, you can protect your deck substructure by applying flashing tape. JoistTape™ Butyl joist barrier can waterproof the tops of the deck joists, rim joists, bearers, and the ledger board. It will hold water out and self-seal around screw holes and metal fasteners to prevent corrosion and joist wood rot.

When this tape is applied to the top of decking joists, over ledger boards, and around support posts, it creates a waterproof seal that helps stop decay and wood rot. Rot is caused by moisture that stays in contact with treated and untreated lumber deck framing and the above decking material. When it blocks this moisture and prevents wood rot, the barrier tape will maximize the life of your brand new deck or restoration.

Aggressive Adhesive

With our butyl rubber joist tape, it can be used on "damper" material. Such as if lumber is not kiln-dried or it is a dewy morning. Always prefer a clean and dry surface! It instantly adheres to most surfaces and has a high adhesion level. Butyl joist tape is less temperature-sensitive and maintains its stickiness at much lower temperatures than non-butyl barrier tape. Meaning, application of the tape can be done at colder temperatures. In addition, homeowners and builders appreciate how quickly they can repair with butyl seal tape.

Prevent Wood Rot!

Butyl Joist Tape Features:

  • Two convenient sizes available in 1-5/8" x 50' or 3-1/8" x 50' rolls
  • High performance 20-22 mil advanced butyl adhesive
  • Pressure-sensitive butyl waterproof membrane
  • Securely bonds to resistant surfaces
  • Is less temperature-sensitive and oozes less in high temps
  • Can be applied in a wide range of weather conditions — very flexible
  • Is more affordable than acrylic or silicone in most instances
  • Flows better around decking screws and deck fasteners, creating a tighter seal
  • Lightly textured Non-Skid surface keeps you sure-footed when walking
  • Black surface allows for sliding wood over it with ease
  • Tear-resistant, durable, and flexible to form around fasteners and corners

Unique Non-Skid Surface: Beyond protection, our Joist Tape features a unique non-skid facer, providing grip in any weather for safer deck installations. UV resistance ensures durability even during extended periods of exposure, making it a reliable foundation for level decking.

DeckWise warranty emblem

WiseWrap® JoistTape™ Limited Warranty

In order to be eligible to make a warranty claim, you must complete the registration for warranty here: www.deckwise.com/warranty/register.html


Intended Uses

  • Joists
  • Posts
  • Ledger Boards
  • Cut Ends & More!
Joist Tape in hand

Provides a Barrier Between Metal and Wood

Corrosive chemicals like alkaline copper quaternary (ACQ) and copper azole (CA), commonly used in pressure-treated wood, can corrode steel joist hangers and other metal hardware. Installing JoistTape™ Butyl barrier tape between metal and wood it creates a physical barrier that prevents the corrosion of the metal surface.

Q: How do I decide which width of JoistTape™ Butyl joist tape I need for my deck?

A: The answer is simple, it’s up to you or your contractor’s preference. Whereas some installers prefer only the top of the joist covered with the 1-5/8” width, others may want to wrap the joist top and sides with the 3-1/8” width. Also, the 3-1/8” width is perfect for double joists.

Q: Is JoistTape™ Butyl Joist Tape compatible with my deck surface material?

A: Yes, JoistTape™ Butyl Joist Tape works with naturally durable wood (e.g. redwood, cedar), pressure treated timber (e.g. southern yellow pine), exotic tropical hardwoods (e.g. ipe, teak, tigerwood), thermally modified wood, wood plastic composite (e.g. Trex, Monarch, TimberTech, Veranda), or plastic (e.g. polystyrene, PVC).

Q: Can I calculate how many lineal feet of JoistTape™ Butyl Joist Tape my deck needs?

A: Yes, you can calculate your deck square footage and estimate how much JoistTape™ Butyl Joist Tape it will need with the Coverage Calculator at the top of this page.

Protect Your Investment!

Enhance your deck's durability and protect your investment with WiseWrap® Butyl JoistTape™. Elevate your deck building experience and prevent wood rot for a lasting and beautiful outdoor space.


Deck Joists

  • 1-5/8" & 3-1/8 Widths:
  • Cut deck joist barrier tape to the proper length according to your stringer.
  • Center over joists, remove release paper, and press in place.
  • (3-1/8 Width:) Firmly wrap and fold the tape over both edge sides of the joist. Small cuts in the tape will assist folding the tape at intersections.
  • To maximize adhesion, compact tape with a small hand roller.
  • When overlapping from end to end, a minimum two-inch overlap is required.

Protecting Deck Posts

When protecting posts, WiseWrap® JoistTape™ Butyl Tape should be applied at the ground level with 2 to 3 inches (5 - 7,5cm) extending above the finished grade. For you to be able to determine the proper location on the post for product placement, you will need to insert the post in the hole, mark the post to indicate the grade level, and then take the wood post out of the hole. To decide what the proper length of tape to use; do the following: without removing the white release paper, wrap the material around the post, making sure that there is enough material for a minimum 1 inch overlap. Cut the JoistTape™ Butyl barrier tape to the correct length. Remove the release paper and wrap it around the post while firmly pressing it into place. To maximize adhesion, roll it on with a small hand roller. To help provide added protection against deep standing water around the post, a small bead of non-silicone caulk may be used at the top edge of the joist barrier tape.

Joists protected with DeckWise Joist Tape

Product Warnings

  • DeckWise® WiseWrap® JoistTape™ Butyl Tape should always be applied to clean, dry surfaces when temperatures are a minimum of 25°F or warmer.
  • If site conditions inhibit suitable adhesion, joist tape can be mechanically attached using staples or nails, or a construction grade spray adhesive can be used to bolster adhesion.
  • WiseWrap® JoistTape™ Butyl is intended to be shielded by either deck boards or siding, and should not be exposed to direct sunlight for a period of more than 90 days.
  • Although it has a slip-resistant surface, it may very well still be slick. Extreme attentiveness should be taken when walking or standing on joists with tape applied.
  Material Safety Data Sheet
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