How to Waterproof a Wood Deck

Water drops beading on wood decking.
  • 24-48 hours
  • Intermediate
  • $120-150
What You'll Need
Stiff scrub brush
Paint stirrer
Deck sealer
Paint tray
Paint tray liner
1/2-inch lint-free nap roller
Small paintbrush
Lamb's wool pad

To be sure your wooden deck continues to be one of the most beautiful assets to your home, you need to waterproof the wood. Leaving it exposed to the elements can accelerate wear and chip away at your investment before you know it. Waterproofing will give the deck a much longer lifespan and keep it looking like it was just built. So, follow the steps below and give the wood the protection it needs.

Step 1 - Prep the Area

It is important to have a clean and clear work space, so start by removing all items from your deck, including furniture and grills. Look for any loose boards or damage once the surface is clear, and conduct any necessary repairs at this time.

Next, use the sandpaper to smooth out any rough spots or light cosmetic damage, such as dings or splinters, and then sweep away any debris. Follow up by cleaning the deck thoroughly with a stiff scrub brush and water. Rinse with clean water after and let the wood completely air dry. Remember, although the top might look dry, it can take up to two days for the inside of the decking to dry as well.

Step 2 - Apply Waterproof Sealer

Next is the sealant. Watch the weather and plan this step for a string of clear days. Using a paint stirrer, mix the sealer thoroughly, and then pour it into a paint tray with a tray liner in it. Coat the wood with sealer using your 1/2-inch lint-free nap roller by rolling it on as if you were painting. Working with two to three sections of board at a time, roll on the sealer in a thin, even coat. Then, use a small paint brush to get the corners and railings. To achieve the correct adhesion to the wood, be sure to apply several thin layers instead of fewer, thicker layers, and take your time.

Step 3 - Distribute the Sealer

In order to make sure that your sealer is distributed evenly, go over each individual section after application with a lamb's wool pad. This will also give the appearance of smoothness in the final result.

Step 4 - Apply More Coats

Add another coat of waterproofing while the first one is still wet. By working in small sections, you will be able to put on two coats at a time without blocking yourself in. Continue in this same manner until you have added as much sealer as you need to keep the wood well-protected.

Once you have gone over the entire deck, let the sealer completely dry before you bring your furniture or grill back. Read the instructions for your specific product to make sure you provide ample dry time, no matter what you've used.