Plywood Decking: A Good Alternative?

Building a deck.

Most of the decks you find will be made out of individual boards and not plywood decking. This is not to say that plywood decking does not make a good alternative to individual boards. Plywood decking is essentially thin sheets of wood glued together to make a thicker sheet. The plywood decking is installed on top of the decking joists in one or more large sheets instead of individual pieces.

Standing Water

One issue you will have with using plywood decking instead of individual boards is the pooling of water. Keep in mind that plywood decking is very flat, and there is no place for water to run off the surface of the plywood. If you do not sweep the water from the plywood, you will potentially face several issues, including mold and the eventual rotting of the plywood decking. With traditional boards, the water simply falls through the spaces between the boards.


Individual boards used to construct a deck can come in a variety of materials, from pressure-treated lumber and cedar to composite boards. Any of these materials will make a great deck. Plywood decking is a lot less expensive than the other materials. One or two sheets of plywood can cover the entire deck.

Proper Plywood Decking Materials

Plywood decking is a great choice as an alternative to regular boards as long as the right plywood is used. Normal plywood is only four or five layers of wood and is bonded together by a basic epoxy. The only kind of plywood you should use as decking material is marine plywood.

There are several differences between marine plywood and normal plywood which make it the best choice as an alternative decking material. Marine plywood is seven to eight layers thick, and the epoxy used to bind the layers is waterproof.

On top of that, the plywood itself is treated with a waterproof sealer. Another major difference is that normal plywood is created with voids in the layers. If you cut into the plywood, you will see spaces between the layers. This is not conducive to being waterproof. Marine plywood, on the other hand, is made so that there are no gaps or voids between the layers.

Ease of Installation

Sometimes you just want to get the deck built and done. The time it takes to build a deck will also impact the cost of the project when it is finished. With traditional boards, the deck can take several days to finish. You may also face the problem of the boards being installed incorrectly, nails not properly sunk, or the wood looking less than perfect. Plywood decking comes in large sheets, which means you can cover the deck easily with the plywood.

Instead of the deck taking days to finish, the job can be completed in hours by using plywood for the decking instead of individual boards. This will also keep the cost down.

Plywood Decking FAQ

Can I use plywood instead of deck boards?

Plywood is affordable material and it is a popular choice for DIY projects of all kinds. Plywood can even be used for large-scale projects, such as an outside deck.

However, you need to use the right thickness of plywood and treat it properly to make it weather-resistant to stand up to the elements. When built properly, a plywood deck can look nice and remain durable for a long time.

How long will a plywood deck last?

Plywood is durable material and will last for 30 to 40 years. When outside and when treated for the weather, a plywood deck can last anywhere from 10 to 40 years, on average.

Will plywood hold up outside?

There are many different types of plywood that can be used for various DIY and building projects. If you're building a deck, marine-grade plywood is a good option.

This plywood is treated to withstand the rigors of weather and it's well-suited for decking.

However, all plywood can become water-resistant with a protective sealant. Plywood can also be pressure-treated to be more weather-resistant.

How do you waterproof a plywood deck?

Plywood can become waterproof with a simple sealant. Polyurethane and other sealants are highly effective on plywood and seal it against water, ice, and the ravages of being outdoors.

What is the best sealant for plywood deck?

Many types of sealant can be applied to plywood to give it a waterproof coat of protection. Polyurethane works well, and this sealant is commonly used on many types of wood.

Epoxy resin is a popular choice for plywood and it performs the same function as polyurethane to seal wood materials.