WiseWrap® JoistTape™ Flashing

Self-Adhesive Joist Flashing Stops Wood Rot

DeckWise® WiseWrap® JoistTape™ is a malleable polyethylene waterproof wood flashing and material, using a rubberized asphalt mastic adhesive. Easily apply to decking joists, around deck support posts and over ledger boards.

Waterproof Barrier Protection

DeckWise® WiseWrap<sup>®</sup> JoistTape™ self-adhesive deck flashing & anti-corrosion barrier

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.

Wood decay can also occur when deck screws penetrate the deck boards, piercing the joist sub-framing below. The application of WiseWrap® JoistTape™ will also seal around decking screws preventing the intrusion of moisture and water.

Great For:

  • Joists
  • Posts
  • Ledger Boards
  • Cuts Ends & More!

Super Grip

Our WiseWrap® JoistTape™ "Super Grip" rubberized asphalt adhesive is a self-sealer around deck screws that blocks a primary pathway for water infiltration into deck joists. When it blocks this moisture and pre vents wood rot, the barrier tape will maximize the life of your brand new deck or restoration.

Corrosion Blocker

When DeckWise® WiseWrap® JoistTape™ is placed between ACQ, CA-B, or ACZA treated lumber and metal surfaces, such as galvanized metal and aluminum, creating a physical barrier that prevents the corrosion of the metal surface caused by contact with the chemicals in treated lumber.

Prevent Wood Rot!

Rotten joists
Taped & protected joists

Deck Joists

  • Cut deck joist barrier tape to the proper length according to your stringer.
  • When applying to the top edges and board ends of deck joists, center over the joist.
  • Remove the release paper and press in place.
  • Firmly wrap and fold the tape over both edge sides of the joist.
  • To maximize tape adhesion, roll with a hand roller.

Deck Posts

When protecting posts, DeckWise® WiseWrap® JoistTape™ 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 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.


Q: After a couple days of rain, how long should I wait before applying WiseWrap® JoistTape™?

A: Our answer is always, “the surface needs to be clean and dry.” If you need to know how clean or how dry, then the joists probably are not dry enough yet. Our WiseWrap® JoistTape™ has two adhesives, rubberized asphalt and acrylic. The two work together to form a better adhesive bond. The acrylic sticks a little bit better on a damp surface. The surface should not be puddled with water, and should not have conspicuous drops on it. Since this is a self-sealing membrane there is NO HARM in adding a couple of staples into it during installation Once the surface dries and it heats up, the rubberized asphalt and acrylic will do their jobs.

Product Warnings

  • DeckWise® JoistTape™ should always be applied to clean, dry surfaces when temperatures are a minimum of 40°F or warmer. If site conditions inhibit suitable adhesion, tape can be mechanically attached using staples or nails, or a construction grade spray adhesive can be used to bolster adhesion.
  • JoistTape™ 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