What is a Waterproof Deck?

Janis Bennett

A waterproof deck is a wooden deck that has been treated with a coating so that water does not seep into the wood. Having a waterproof deck means having a deck that is more likely to stand the test of time. When a deck is not treated, water will seep into the wood and cause rotting and erosion, which can cause the deck to fall apart over time. Making a deck waterproof or water-resistant is a fairly easy do-it-yourself weekend project.

Use a special type of cleaner to protect cedar and redwood decking.
Use a special type of cleaner to protect cedar and redwood decking.

A deck that is rotting can be dangerous; it can cause injury and is likely to attract insects. A simple way to prevent a deck from rotting and extend its life is by making it waterproof. The most common way to obtain a waterproof deck or porch is to apply a sealant on it. Homeowners should look specifically for a water-repellent sealer that works well with the type of wood the deck is made out of.

To keep a waterproof deck looking beautiful, a new coat of sealant should be applied every few years.
To keep a waterproof deck looking beautiful, a new coat of sealant should be applied every few years.

To waterproof a wood deck, first it should be cleaned with a deck cleaning solution. This solution can be purchased at local hardware and home improvement stores. The manufacture's directions should be followed closely. Redwood and cedar wood require a special type of cleaner, so a product designed specifically for these types of wood should be used. A pressure washer can also be used, but if the pressure is too high, it can damage the wood.

After cleaning, the wood should be allowed to dry thoroughly before the water-repelling sealant is painting on. A brush, roller, pump-up garden sprayer, or paint pad can be used to apply the sealant. Waterproof sealants come in a variety of tints and finishes.

The best sealant for a deck is one that will provide the desired look and that will work with the type of wood used on the deck. A homeowner should always check the label of the waterproofing product for an indication that it passes local standards for waterproofing; in the US, these standards are determined by the American Society for Testing and Materials (ASTM). Not all products labeled as waterproofers provide the same level of protection.

If a deck or porch is made with the one of the newer composite-decking materials, it may have waterproofing properties built right in. There are a few different brands and types of composite decking, from vinyl to PVC. A homeowner should check with the product manufacturer to see if a waterproof sealant is needed.

To keep a waterproof deck looking beautiful for years to come, a new coat of sealant should be applied every few years. A good way to check if a deck is still water resistant is by using a "splash test." If water splashed onto the deck absorbs into the wood quickly, darkening the surface, then the wood is no longer resistant to water. On a waterproof deck, the water will sit on the surface, beading up, or run off.

Untreated wood is susceptible to rotting and erosion.
Untreated wood is susceptible to rotting and erosion.

You might also Like

Readers Also Love

Discussion Comments


@rundocuri- Don't wait much longer to waterproof your deck. Once cracks begin, they will get larger and deeper with each rainstorm and bright, sunny day. Also, when you choose your waterproof deck coating, make sure you buy a product that is good quality. Now that you have deck wear and tear, it is not the time to cut corners on costs for this type of product. To be on the safe side, you also may want to consider adding an extra coat beyond what is recommended by the manufacturer.


@rundocuri- It couldn't hurt to give waterproofing your deck a try. A good sealant should help to moisturize your deck while keeping out damaging rain water and snow. This should prevent further damage if you do it soon.

However, if your deck has major cracks and other damage, you may have to replace some of the slats before you apply any waterproof deck coating. Otherwise, you could be putting off a minor repair that will become a major expense if you don't fix it now.


My deck is starting to show signs of being weathered. There are cracks developing, and the wood looks dry. I'm afraid that I have neglected waterproofing it for too long. Based on its signs of wear, does anyone think that it is too late for deck waterproofing?

Post your comments
Forgot password?