Protect Your Deck Where it Matters Most

If you ask deck builders the most likely place a deck will fail, they’ll almost all tell you the same thing. Look at the point where the deck attaches to the house: the ledger board.

What causes ledger board failure? And what can you do to protect this vital piece of substructure?

There’s a great solution, and we’re glad to share it.

Why is the Ledger Board So Critical?

When wood rot causes the ledger board to fail or screws rust and break down, there’s nothing standing between your deck and collapse. One builder said he pulled a deck away from a house with just a good yank because the original builder used 2” nails that had corroded.

“The most vulnerable part of a deck is where it meets the house,” a builder said in a recent survey.

What Causes the Board to Break Down?

A ledger board is almost always made of treated wood. Any wood that gets wet again and again will eventually begin to rot. Unfortunately, there’s often a tiny gap between the house and the deck that allows water to seep down onto the ledger board.

“Most cases of deck failure are due to moisture issues getting on or into lumber. It’s actually going to be a larger issue because younger trees do not have close growth rings. Moisture will be able to penetrate easier,” one builder explained.

Even worse, leaves and other debris can get trapped in this space. Because that debris can stay wet and sit on the wood, the wood never gets to dry. The more often the wood gets wet, the quicker the failure can happen.

How Can You Prevent a Rotten Ledger Board?

The best way to keep wood from rotting is to ensure it never gets wet. Using waterproof flashing is the only sure way to protect the ledger board. Watch this video to understand how flashing at the ledger should be properly applied. The flashing should extend to the surface of the exterior wall finish.

Building codes refer to the need for approved  corrosion-resistant flashing, defined as “the ability of a material to withstand deterioration of its surface or its properties when exposed to its environment.”

Trex® Seal Ledger Tape, a self-adhering 11”-wide butyl tape reinforced with an aluminum liner, offers a superior alternative to traditional ledger flashing by creating a waterproof barrier for the ledger board. It also seals any gaps between the ledger board and the substructure for optimal protection.

Because dissimilar metals can cause corrosion, Trex Seal Ledger Tape is Code AAMA711 compliant.

Builders have told us that metal flashing can be quicker to install but doesn’t completely seal the ledger board. There’s not much point in applying flashing that isn’t waterproof. With Trex® Seal Ledger Tape, our 5-1/2″ double-release liner ensures accurate installation and a watertight seal.

Surveyed builders say Trex Seal offers a “wider area coverage to keep more structural boards covered — a more complete seal for facia boards where water can be trapped.” And “in our experience, Trex Seal is designed specifically for deck installations, both in its form and size. It comes in the appropriate sizes needed for proper flashing of deck framing members, and it can bend and be set in place without it flexing back like other flashing tapes.

Give it a try on your next deck build. Check out the product specifications here.