Joist Tape That Stops Deck Frames Rotting

Most deck frames fail from the top down. Water sits where the boards rest on the joists, soaks into the timber and slowly causes rot. Every screw you drive also creates a new path for moisture to get in. Walther Strong Deck Tape seals the top of each joist, so water runs off rather than soaking in. As a result, your deck frame lasts far longer.

Why It Matters With Composite Decking

Composite boards don’t rot, but the timber frame underneath still can. In fact, because water drains off composite boards so readily, more of it can end up on the frame below. That’s why joist tape is just as important under composite decking, including Millboard, as it is under timber.

Why Choose Walther Strong Deck Tape?

Non-butyl formula: Many joist tapes use butyl, which can break down over time. Deck Tape uses a polymer acrylic adhesive instead, which is completely UV stable and keeps its integrity for longer.

Self-sealing: The adhesive bonds into the timber and seals around screws and nails. Those fixings are one of the main points where moisture gets in.

Easy to work with: You can reposition it as you go, and it tears easily by hand. The adhesive side doesn’t stick to itself, so there’s less waste.

Low profile: It overlaps cleanly without adding noticeable height, so your boards still sit level. Boards also slide easily along taped joists during installation.

Long-lasting: It forms a permanent adhesive bond and comes with a 25-year guarantee.

How to Apply Deck Tape

First, make sure your joists are clean and fully dry. If you’ve used a timber preservative, let it dry completely before taping. Next, peel back the liner and lay the tape centrally along the top of each joist. Then press it down firmly along its full length. Where two lengths meet, overlap the ends. Finally, lay your decking boards and screw straight through the tape.

You can tape your joists in advance of fitting the boards, as the tape won’t deteriorate in the meantime. However, don’t apply it in the rain.

Where to Use It

• Tops of joists and beams
• Ledger boards fixed to the house
• Around joist hangers
• Tops of posts
• Timber frames under composite decking

Everything for Your Deck From One Supplier

At Creative Landscaping Works, we supply Millboard composite decking and the accessories to fit it properly, all from our base in Letterkenny. Not sure how many rolls you’ll need? Send us your deck plan and we’ll help you work it out.

FAQs

How many rolls do I need?
Add up the total length of all your joists, then divide by 20. For example, a 4m-wide deck with 3m joists at 400mm centres has 11 joists. That’s 33m of joist, so you’d need two rolls. Allow a little extra for ledger boards and overlaps.

Do I need joist tape under composite decking?
Yes. Composite boards don’t rot, but the timber frame underneath can. Because water drains off composite boards so quickly, the frame can actually take on more moisture.

Can I screw through the tape?
Yes. The adhesive self-seals around screws and nails, so fixing straight through it is exactly how it’s designed to work.

Can I apply it to wet timber?
No. The timber should be clean and fully dry. Also, avoid applying it in the rain.

Is 65mm wide enough?
For standard single joists, yes. Where boards butt together over doubled joists, you may want to run two lengths side by side to cover the full width.

Can I use it on treated timber?
Yes. Deck Tape has been tested with all timber treatments. Just make sure the treatment has fully dried before you apply the tape.