Is Butyl Tape Waterproof and Permanent?

When you’re building an outdoor deck that’s exposed to the elements, you want to be sure to do everything possible to extend the timber’s lifespan. And when it comes to sealants, you want to be sure to use the best product possible for the job. For example, butyl tape can keep your timber protected from rain and snow by creating a protective barrier that keeps moisture and condensation out, ensuring your investment stays dry for the long run.

What is Butyl Seal Tape?

Butyl tape is a rubber-based adhesive developed to enhance traditional rubber adhesives. It has a very high adhesive level and sticks to most smooth surfaces quickly. It’s also extremely resistant to high and low temperatures and can serve as an excellent bonding agent in environments where moisture is a factor, such as outdoor decks. Butyl rubber tape is also a great quick fix for most household and vehicle projects, like gutters or RV repair, that require patching a hole or leak.

Flexibility and strength are butyl tape’s strong suits, making it the perfect material to keep around and use to prolong the stability of your deck. Besides timber, butyl seal tape is great for repairing tape on surfaces like rubber roofing, galvanized metal, fibreglass, textile, plastic, aluminium, and any other typical RV, home, automobile, and boat surfaces.

Is Butyl Tape Waterproof?

Over time, exposure to water through weathering is a threat to any deck, even those made with treated timber. That’s why it’s crucial to protect your deck’s timber from the earliest stage at construction with a waterproof seal. Decks often experience erosion due to water damage within the first 8 to 10 years after construction. Still, by being proactive during the early phases to keep moisture out using a strong adhesive waterproof tape seal like butyl tape, you can keep your deck sturdy for years beyond that.

Butyl tape is resistant to water and extreme temperature conditions, vapour, and corrosion. As a flexible sealant tape, it bonds well to seal those small holes in your deck that is prone to timber rot: screw holes, the tops of the deck joists, rim joists, bearers, and the ledger board.

To ensure your deck stays leakproof and stable for years to come, it’s important to choose a high-quality sealing tape. Trex Protect Joist & Bearer Tape comes with a 25-year warranty backed by Trex, the World’s No. 1 Decking brand. And for less than £75, a roll of butyl tape ensures that an average-sized deck will stay dry and secure from the structure underneath to the deck on top.

Is Butyl Tape Permanent?

Butyl tape is certified airtight and watertight against the most extreme weather conditions, including heavy rainfall, direct sunlight, cold winters, and UV.

How Long Will Butyl Tape Last?

Due to its intense temperature resistance, butyl adhesive tape can last in a cool room without oozing into a puddle that becomes unusable. However, experts recommend storing your roll of sealant tape in the refrigerator for around 2 to 6 hours before use for best results.

How to Properly Install Butyl Tape

Before you start, be sure to choose a self-adhesive tape that is easy to install with a minimal amount of trimming. For example, a butyl tape applied directly onto your deck boards won’t require a lot of cuts. Trex Protect® Joist & Bearer Tape comes in two separate widths and is applied to both vertical and horizontal surfaces.

Use our Materials Estimator to determine just exactly how much joist, bearer and rim joist tape your project will require.

Follow this video for a few simple steps on properly applying your sealing tape. The steps are also summarized below:

In preparation, clean the deck, ensuring it is dry and free from debris.
Remove the tape backing while applying directly to the surface. Run your hand over the tape and firmly press it onto the joists and bearers.
After covering all horizontal and vertical surfaces, cut the tape to length with a utility knife or scissors.

Apply Trex Protect to all the joists, rim joists, bearers, stringers, support posts, and the ledger board. The tape can also serve as a barrier between timber and galvanized metal, such as joist hangers. Smooth out any bubbles or wrinkles, using a hand roller if need be. Be sure to always apply to clean, dry timber.

Which Butyl Seal Tape Should You Buy?

Butyl tape can strengthen the integrity of your deck, but it can also serve as a helpful tool to have around the house as a quick fix for any holes or leaks that need waterproof repair. It shouldn’t cost you a fortune, but going for the cheapest option will definitely reflect a poorer quality for what should be a durable, dependable material. In addition, because butyl seal tape adheres firmly to a wide variety of surfaces, resists strong weather conditions, and can flexibly adjust to various crevices, it makes for a terrific deck flashing tape. Besides timber, butyl tape is compatible with these surfaces:

● Glass

● Rubber roofing

● Metal roofing

● Aluminium

● Metal

● Plastic

When selecting which butyl tape is best for your project, consider these factors:

Installation: Any contractor or DIY homeowner will tell you to buy a butyl tape that is easy to install and requires little trimming. Because of its super grip, you want to be able to put the tape down once on a dry surface. A self-adhesive butyl tape that lies directly on the boards requires minimum cuts with little overlap. It can also adhere to and reinforce galvanized metal, like deck screws, hangers, and fasteners.

Durability: Choose heavy-duty adhesive tape with an excellent warranty. Trex Protect Joist & Bearer Tape comes with a 25-year warranty backed by Trex, the World’s No. 1 Decking brand. Unfortunately, newer products don’t enjoy this kind of track record.

Quality: When applying flashing tape to your bearers and floor joists, you want to be sure to purchase a tape that is not too thin and not too thick. With thin tape, you risk long-term durability of the tape. On the other hand, the thick tape can be difficult to install. Therefore, you want a tape that will last as long as your bearers and joists. TTrex Protect is available in three widths 50 mm for joists, 100 mm for double bearers and 279.4 mm for rim joists.

Investments in your home, such as an outdoor deck, deserve the best in support. For less than £75, keep your timber from rotting and keep your substructure lasting as long as the deck it supports above.

Dave Kile

Dave Kile is the owner of IBP, LLC, the company behind some of the decking industry’s most successful innovations, including Trex® RainEscape®, Trex® Protect™ and Trex® Seal. Over the past three decades, he has achieved incremental success by immersing himself in the industry, listening to customers and bringing new products to market that improve efficiency and effectiveness.