How To Choose The Right Waterproof Coating For Your Deck

Waterproofing your deck is the most important step you can take to maximize its lifespan and minimize maintenance requirements. This is especially true for authentic wood decks, which are more porous than composite decks and are more prone to rotting when exposed to rain. The type of waterproofing that you choose will determine its resistance to UV radiation and traffic, as well as its effectiveness. Here are some details about two common types of waterproof coatings to help you make the right decision for your deck.


Polyurethane is one of the most popular forms of waterproofing for residential decks. This type of waterproof coating provides excellent resistance against moisture as well as traffic, and is very easy to install. For best results, you should make sure that the polyurethane coating that you choose is oil-based, as this type has superior water resistance to water-based polyurethane.

Polyurethane waterproofing can be applied directly to your deck without staining, but it is necessary to clean it first to ensure that the coat adheres properly. Scrubbing the deck with diluted bleach and then pressure washing it is adequate to prepare the deck for the polyurethane coat. Prime the deck a water sealing deck stain after it has been cleaned and allow it to cure for three days. After the deck has cured, mix the polyurethane according to the manufacturer's instructions and apply it evenly using a brush, roller, or hand sprayer.

While polyurethane is a suitable deck coating for many homeowners, there are a few downsides that you should consider. Most importantly, you should check the can for the minimum and maximum temperatures that you can apply the coating, as it may not set properly in cold or hot weather. You may also notice that UV causes polyurethane deteriorates more quickly than other types of waterproof coatings depending on the level of direct sunlight that your deck receives.


Rather than coating your deck with liquid polyurethane, you may choose to use a thin sheet of vinyl. Vinyl makes your deck virtually impervious to water if it is installed correctly. It is also much easier to make sure that your entire deck is waterproofed, as you will clearly be able to see any spots that are not covered correctly.

To install vinyl deck waterproofing, minimal cleaning is required. Simply sweep off the deck to get rid of dirt and debris. The next step is to nail galvanised metal cant strips on the edge of the deck that is adjacent to your house, as well as metal flashing around the entire perimeter of the deck. The cant strip should bend at a 90 degree angle around the edge of the deck.

The next part of the job is easiest for a two-man team to complete. First, lay the vinyl sheet across your deck and smooth it out so that there are no visible wrinkles. Overlap the vinyl one to two inches onto the cant strip, and tack it in place. Then fold the opposite edge backwards and use a roller to apply adhesive to the deck and to the back of the vinyl. Have your helper assist you in smoothing the adhered vinyl onto the deck. Remove the tacks and complete this process for the other half of the vinyl. When this process is finished, you should have slight overhang around the flashing and cant strip. Trim the overhang to be flush with the flashing, and apply overlap cement to hold the vinyl in place.

While vinyl will stand up excellently to water, traffic, and UV radiation, you must take care to make sure that it is not torn by sharp objects or burned by hot coals from the grill. Vinyl will also hide the natural beauty of your deck's wood, but many vinyl covers have decorative patterns to make up for this fact.

Both of the waterproofing methods explained here can protect your deck from moisture and keep it in good shape for years to come. To choose the right waterproofing for your deck, consider whether you prefer a coating that displays the natural beauty of the deck but requires occasional maintenance, or one that hides the deck wood but can remain hassle-free for years to come.