Can I Put Composite Decking Over an Existing Wood Deck?

Replace decking

Creaking, wobbling and rotting floors, these are the signs that you should replace your wood decking. Not only does it look bad, but it’s also a safety hazard. It would help if you replaced your old wooden deck as soon as you can. 

Since wooden decks have a limited life span, you may want to use something a little more durable. In which case, composite decking is perfect for the job. The question is, can you put composite decking over existing wood decking?

Putting Composite Decking Over Wood

Whether your wooden deck is old or needs replacement, you may have considered placing over some composite decking. You might have thought that you can save time effort by putting composites over an existing deck. But the real question is, can you do such a thing?

The answer to that question is yes you can. A composite deck can be used to cover the existing wood deck if an old deck is strong and sound; one key point to take into consideration is drainage and how the water will drain off the two decks. Those that have built a deck before will understand how difficult it is to accomplish this as there are many complications that can occur when doing so.

Therefore we do not recommend building a composite deck on top of a wooden deck.

Should You Place Composites over Wood Decks?

can you put composite decking over existing wood decking?

Yes, you can place any decking over an existing wood decking, even composites. But is that something that you should do? No, not really. While it seems logical to place composites over existing decking, doing it has a lot of downsides. 

Before doing anything, you should first consider the quality of the existing wooden deck. How old is it? Is it new? Or is it rotting and needs replacement? Why are these questions crucial? When placing materials over existing decking, the latter can directly affect the former. In the case of wooden decking, if the existing floors are old and rotting, the new materials on top will have their lifespan reduced. Even though composites are not prone to rot, the surrounding structure will suffer. Moisture will be trapped underneath and will damage both the pre-existing wood decking and composites. The frame or foundation will also be affected by wetness, which can cause it to rot and deteriorate. Placing composites over wood will only do more harm than good. In the end, it will only cost you more money.

What if your deck is new and you only want to replace it? Can you place composites over them? If the floor and the frame are relatively new and wood materials are pressure-treated, there’s a good chance that it won’t affect the overall quality and lifespan of your composite decking boards. Even if it did, it won’t do as much damage as an old deck would cause. But the question is, is there a reason why you should replace a newly built or still-in-good-quality decking? Before doing anything to your floor, consider the price of the materials, since composites do have a high initial cost.

Knowing that placing composites over existing wooden decking is possible but not recommended, what can you do instead? What if you have to replace it?

What to Do Instead?

So you want to replace your deck. What can you do? To avoid the composites from being damaged by moisture and rotting, you should replace the existing wood decking. It means that you have to remove all the wooden boards and replace them with composites. You will also have to do something about the existing frame. If you want a DIY approach to this project, you can check out many instructional articles and videos of how to do it. 

One thing is for sure; if you want a new composite decking, it’s not enough to only place them over an existing floor, especially when the deck is old and rotting. If your wooden deck is new or in good quality, it’s possible to place the composites over. But even so, it’s not recommended to do so. In the end, you are still the one who will decide whether you want to put composite decking over an existing wood deck. 

Tags: Existing Wood, replace decking, Wood Deck

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