Can You Put Composite Decking Over Wood? (Find Out Now!)

Matthew Mountain
by Matthew Mountain

Composite decking is sought these days for a variety of reasons. Many homeowners like how it looks, others like the feel, and everyone agrees that it’s easy to maintain. But what if you already have a wood deck, you want a composite deck, but you don’t have the money or time to tear down the deck you have in order to set up a new one?

Such is the question this article answers, and some tips for installing composite decking will be put forward as well. And if you need help with a composite deck installation, feel free to reach out to an expert, as they’ll ensure you get the composite decking configuration you’re looking for.

While you can put composite decking over wood, most professional deck installers would advise against doing so, as this will lead to more problems than benefits. The biggest problem has to do with drainage. If the deck isn’t able to drain properly, water is going to get trapped and then cause material deterioration, rotting, and various growths.

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When Wood Should Be Replaced With Composite Decking

If you notice a lot of creaking from your wood deck, it may be time to consider a replacement. If there’s wobbling too, then it’s quite likely deck replacement will be required sooner rather than later. And if there’s rotting, your deck should be replaced immediately, as it could be a big safety hazard in this state.

Since deck replacement is just around the corner, wouldn’t it be good to replace your old deck with something more durable and long-lasting? If you agree, then pursue a composite deck replacement. And these days, you can do the replacement without ever removing one piece of preexisting wood decking.

Putting Composite Decking Over Wood

The main reasons why individuals consider putting composite decking over preexisting wood decking are they think doing so will save time, require less effort, save money, and require fewer materials. Many individuals achieve great results when pursuing this kind of replacement, but there are some things to keep in mind before you attempt to put composite decking over wood.

Again, it’s at this point that a professional should be contacted, as they’ll be able to tell you whether or not putting composite decking over wood is feasible in your situation. Here are some things to consider:


The first thing you should consider when attempting a wood deck replacement is drainage. If you cover the deck in composite decking, you’ll need to ensure that there isn’t a drainage problem. After all, water and moisture could get under the composite decking and rot the wood underneath.

Trapped water could also lead to moss, algae, mold, mildew, and/or bacteria growth. These unwanted growths and organisms will keep reappearing unless the drainage problem is fixed. A lot of professional deck installers discourage putting composite deck over wood decking, specifically because of the associated drainage issues.

Furthermore, there may be spots where layering decking will just not be feasible. But if you can get around this, then you shouldn’t be discouraged from pursuing this kind of decking replacement.

Preexisting Deck Strength

Of course, you don’t want to be installing composite decking on a deck that’s on its last legs. Therefore, if your deck is not in near-great condition, you really shouldn’t be pursuing composite decking replacement.

You may want new composite decking because you think it’ll beautify your deck, and your assumption is probably right. But you must consider: Is it worth making your deck more attractive if the deck’s structural integrity is compromised?

To know whether or not your deck is worthy of this kind of replacement, you should consult a decking professional, as they’ll be able to tell you the strength of your deck and how much more time you can expect to get out of it.

Other Important Things to Consider

While replacing wood decking with composite decking is possible, the majority of deck installers out there would probably discourage you from pursuing this, and that’s because there are a lot of downsides associated with this kind of replacement.

Assessing Deck Condition

The first thing has to do with wood deck condition. There are a lot of factors that determine the condition of a wood deck, and often it’s difficult to pinpoint exactly how reliable a deck is at the present moment.

One will have to consider the deck’s age, the material it’s made out of, and the prevalence of rotting. And if you put composite decking on wood that’s rotting, the composite material may degrade as well.

Even though composite decking is mostly impervious to rotting, it’s the rest of the structure that will suffer. And if your deck’s wood splits, the composite decking won’t be able to maintain the structure.

Financial Considerations

One must also consider the costs associated with this kind of deck replacement. If you’re putting composite decking over wood because you think doing so will save you money, you have to consider the drainage issues and structural issues addressed already in the context of money.

If it doesn’t cost you a lot to put the deck up, but then later on you have to spend a lot on a replacement or an expensive repair, then you really aren’t saving money in the long run. Plus, every time you need work done, you’re going to need assistance, and therefore you’ll be paying for labor.

If you get a first-rate deck installed on the first go, all you’ll have to do is spend money on maintenance later on. This won’t be much!

Immediate Replacement

You may have better luck with a composite deck replacement if the wood underneath is pressure-treated; that’s because these boards can usually withstand anything that’s thrown at them. But again, the main thing here is newness; you should only install composite decking over new wood.

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Final Note

The most important takeaway is that you should only do this kind of deck replacement if the boards are brand new. But if you’re making major alterations on a brand new deck, why wouldn’t you have just made these ahead of time? This kind of work entails unnecessary costs and labor, and these added expenses can be avoided if you just install a 100% composite deck first.

Matthew Mountain
Matthew Mountain

Matt loves everything DIY. He has been learning and practicing different trades since he was a kid, and he's often the first one called when a friend or family member needs a helping hand at home. Matt loves to work with wood and stone, and landscaping is by far his most favorite pastime.

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