How to Waterproof the Deck You are Building

Often when homeowners think about waterproofing a deck, they focus on using a sealant on the boards to reduce weathering. But as a builder, you know that water damage is more than skin deep!

To ensure your reputation as an outstanding builder and help your homeowners’ decks last longer, you have to think about what’s protecting the timber you can’t see. In fact, serious damage often starts with the joists and the boards that fit against the house. Here, moisture can become trapped and wreak havoc on your well-built deck.

Guard against the water on three fronts:

1. The average deck begins to experience water damage within 8 to 10 years. Trex Protect fights the rot. This non-skid, self-adhesive deck flashing tape shields the tops of joists, rim joists, bearers and the ledger board from moisture that can lead to the development of rot and timber decay and the loosening of deck screws and fasteners. Trex Protect guards against costly future water damage — at a low cost. For an average size deck, measuring 3.6m x 7.3m, five rolls of Trex Protect Joist Tape and one roll of Trex Protect Bearer Tape will be all you need. So for less than a $130 investment, the deck substructure can last as long as the decking it supports. To find out exactly how much Trex Protect Joist, Bearer & Rim Tape your project requires, use our Materials Estimator.
2. Easy-to-install, self-adhesive Trex RainEscape Wall Flash seals the space between your house and ledger board to keep water out. Wall flash is best used during the construction of a new deck and is another small investment with big returns. Trex RainEscape® Wall Flash comes with a 25-year warranty from Trex, the world’s #1 composite decking brand. See how Trex RainEscape® Wall Flash protects in this video.
3. If you have a second-story deck, you can install a deck drainage system to divert water away from the joists and bearers. An over-the-joist deck drainage system such as Trex RainEscape provides 100% protection from the damage caused by timber repeatedly getting wet. This type of deck drainage system not only covers and protects the entire timber substructure; it also creates a usable area beneath the deck that can be used for additional living space or storage.