Can You Put Composite Decking Over Wood?

Can You Put Composite Decking Over Wood

Can you put composite decking over wood?

One of the questions we are often asked is “can you put composite decking over wood?”. Actually, laying deck boards on wood is not recommended. Since this solution will require more issues to consider, the benefits are fewer than the hidden troubles. It will actually cost more money and time.

You may have completed your wood deck installation years ago and meticulously maintained it every single year, but it eventually starts to crack, rot or warp after some time and if left untreated, it poses a threat to you and your family’s safety. Then you are faced with a choice of how to refurbish your wood deck to keep it safe for a long time. 

As a one-stop composite decking manufacturer and supply chain, the composite decking is shipped directly from the factory at wholesale price. You will find your decoration solutions in Unifloor.

Install composite decking over existing deck

Compared to wood decking, WPC decking has a longer life span, so it is also a very suitable choice for many people to choose to replace their wood decking with composite decking. So what to do with your old deck? Should you remove it completely or install a WPC deck on top of the old one? This has to do with the condition of your old deck.

This article will help you analyze whether you can install wood plastic composite decking directly on top of your existing wood deck. What are the benefits and what are the pitfalls of doing so, as well as some suggestions for refurbishing your deck, so hopefully you will find some of the information you need here.

When can you do that?

Wood Frame Ppmds

If you have checked that the substructure of the original wood deck is strong enough, then building a wood-plastic composite deck on top of it can save you time and some costs. If you are not sure how long the original substructure will hold up, then you will need to remove it all and rebuild it.

Remove the old deck

Laying Deck Boards 5k

Why is it important to remove the original wooden deck? There are three factors that need to be taken into consideration when we do a project to refurbish a deck, the first is the stability of the substructure, the second is drainage, and the third is air circulation. If the wood plastic composite deck is installed directly on top of the wood deck, it will face several problems that cannot be ignored.

1. Affects drainage. Water will slip between the layers of boards and cause mold stains.

2. Air circulation is not guaranteed. There is not enough air circulation under the wood-plastic composite decking, which will cause the production of mold and mildew, and over time, will destroy the wood-plastic composite decking as well as the original wood decking.

3. Gradual decay of the wood deck and bottom frame. Moisture and accumulated mold that has not been successfully drained will accelerate the decay of the wood deck, which will degrade rapidly over time.

Build a new frame

Subframe Of Composite Decking 12

If your wood deck is in a damaged, rotten or unstable condition, we strongly recommend that you remove the deck and reinstall it.

If you continue to install WPC decking on top of this, the fading of the bottom deck will cause your deck to eventually collapse. Because WPC decking is very durable, it is best that the frame supporting the WPC deck is new and used with the WPC deck to avoid subsequent problems with the frame that could lead to the need to reassemble the deck or other safety issues. Unifloor offers a complete range of frame-building accessories that make it very easy to build a strong bottom frame.


It is not recommended to install wood-plastic composite decking directly on top of the existing wood decking for both sustainability and safety reasons, and it is very important to remove the old frame and the existing wood decking. 

Contact Us

More To Explore