Waterproof Decking Materials & Options
While water gives life, it also destroys, especially when it comes to construction. In fact, your home may have no greater enemy than water.
Decks are typically designed with spacing between boards to help create drainage. While draining can be helpful and prevent water from pooling on your deck, the spacing may allow water to seep underneath decking boards, where it can become trapped on wooden joists. It can also create problems when you want to use the area beneath your deck.
That’s why, as you plan for a deck, waterproofing should be your top priority. From waterproof decking boards to aftermarket sealers, exploring all of your waterproof decking options is an important step in making an informed decision about which choice is right for your situation.Let’s take a top-down approach.
How to Waterproof Your Deck Boards
Starting from the top -- the decking boards -- the waterproofing begins. Composite boards, by manufacturers such as Trex, don’t need additional sealing or waterproofing. Trex decking, made of 95 percent recycled materials, won’t rot or warp and never needs staining or painting. If you are building a wood deck, you can often benefit from additional protection. The most common ways include sealers, coatings, and vinyl membranes.
If you choose wood boards, you need to maintain and seal the wood properly. Applying a clear sealant keeps water from seeping into the porous surfaces of the wood and reduces the risk of rot.
Water should bubble up on your deck like on a waxed car. If it doesn’t it is likely time to seal again. Most builders recommend sealing wooden deck boards every one to three years. Check the manufacturer’s directions on your sealant for more guidance.
Deck coatings are a thick substance -- that can be made from liquid rubber polyurethane, latex, enamel, acrylic or other material -- that are used to resurface a deck and make it waterproof. Adding a new coating requires cleaning and preparation of the surface. The prep work is worth it, though, as the results can be slip resistant, available in a wide variety of colors. Coatings, however, can be difficult to apply and may peel easily. They can be applied similar to paint with a brush, roller, or spray. In addition to the time spent prepping and painting on the coating, the coating also needs time to cure and adhere to the deck.
Coatings are a polarizing method of waterproofing a deck among homeowners. Some feel they do a good job of masking cracks and splinters in wood decking. However, others feel that they are difficult to apply, can feel rough and gritty on bare feet, and can also make it difficult to repair a deck. As coatings can smooth over splintered wood, it can also make it difficult to find screws and other decking components in the event repairs are needed.
Like a sealer, coatings also require periodic cleaning. However, they are a more expensive and time-consuming method of waterproofing a deck.
On-deck membranes are basically waterproof flooring. Membranes can be constructed with materials that are resistant to mold, mildew, and UV. They can provide slip resistance that can be otherwise lacking from some kinds of decking. While membranes have a higher upfront cost than sealers, they don’t require re-application of fresh coats.