What is Bearer Tape?

Bearer tape is deck protection tape, an inexpensive add-on with big results.

While composite decking has grown more popular in recent years, the deck’s supporting structure is most often still made of timber. Because timber is economical and readily available, it is a popular choice for framing new deck construction.

The challenge: Water damage. 

How do you go about waterproofing? What building materials or building products can make the biggest difference for a small price?

The answer: Bearer tape, also known as joist flashing tape. 

Water leaking through your deck boards can cause hidden damage unless your bearers and joists are protected. While sealants are important to protect your decking boards, you need protection for your timber substructure too.

Using a quality deck bearer tape can protect the top of the joist, rim joist, and ledger board from developing rot and timber decay. A butyl-based tape not only blocks moisture but also helps stainless steel decking screws hold longer and is stronger than acrylic or asphalt-based tape. Once you’ve done the work with your screws and spanners, you want that work to last!

Other benefits of bearer tape: it can act as a barrier between timber and galvanized metal such as joist hangers, help seal deck fasteners, prevent moisture penetration, eliminate splitting from freeze and thaw and provide a non-skid surface, making it safer during installation.

Learn more about choosing the right bearer tape during construction can add years of life to your deck:

Which Material Should You Choose?

There are several factors in choosing bearer protection tape. 

First, the material.

Bearer tape typically comes in three types: acrylic tape (G-Tape), butyl, and bitumen. Bitumen, made from petroleum and asphalt, will dry out over time, reducing flashing effectiveness. That leaves butyl or acrylic. 

Butyl rubber tape has many advantages over an acrylic-based tape. Butyl tape, such as Trex Protect, is stickier, endures less stain, has less high-temperature oozing, and can be applied in a wide range of temperatures. Butyl tape is also more rubbery than acrylic-based tape, allowing it to flow better around the deck screws holes to create a tighter seal. 

How Easy is it to Install?

Any contractor or D.I.Y. homeowner will tell you to buy a butyl tape that is easy to install and requires little trimming. A self-adhesive butyl tape that lies directly on the boards requires minimum cuts with little overlap.

What’s Best: Thick or Thin?

When applying bearer tape to your bearers and joists, you want to be sure to purchase a tape that is not too thin and not too thick. With thin tape, you risk the long-term durability of the tape. A thick tape can be difficult to install. Trex Protect is available in two widths: 40 mm x 20 m for joists and 100 mm x 20 m for bearers.

To find out exactly how much Trex Protect® Joist & Bearer Tape your project requires, use our Materials Estimator.

 See why you should choose Trex Protect® in this video.

How Long Will It Last?

You want a tape that will last as long as your bearers and joists. 

Trex Protect is guaranteed to withstand the test of time. It comes with a 25-year warranty, so it lasts as long as the decking it supports. Acrylic tape comes with only a 300-day warranty.  

The average deck begins to experience water damage within 8 to 10 years. High-performance Trex Protect fights the rot and guards against costly future water damage — at a low cost. Protecting an average size deck measuring 3.5m x 7.5m will require approximately 5 rolls of Trex Protect Bearer tape and one roll of Trex Protect Bearer Tape. For less than a $120 investment, your deck substructure can last as long as the decking it supports.

How Do I Install Tape?

Installing self-adhering bearer tape is a relatively simple process, with three main steps. 

Begin by preparing your surface.  Apply Trex Protect Joist, Bearer & Rim Joist Tape to horizontal and vertical surfaces. It has three widths making it convenient to use for double bearers, joists and rim joists. 

When pulling deck boards onto the deck, a piece of plywood or wafer board can be used to overhang the edge of the deck. This treatment will prevent the product from rolling up and pulling up from the joist.

Installing joist tape has just a few straightforward steps, detailed in this video. You can also find a summary of the instructions below:

1. 1. Prepare. Clean the surface, ensuring it is clean and free from debris. 
   2. Remove the butyl tape backing while applying directly to the surface. Run your hand over the tape and firmly press it onto the joists and bearers.
   3. Apply Trex Protect to all the joists, rim joists, bearers, stringers, support posts, and the ledger board. After covering all horizontal and vertical surfaces, cut the tape to length with a utility knife.

As you begin deck building, don’t forget the bearer tape, your hidden deck protection. Don’t let timber rot become the enemy of your beautiful outdoor living experience.