Can You Put Composite Decking Over Wood Decking?

January 2024
Anton White

Diving straight into the heart of your decking dilemmas, we at Ovaeda understand the common conundrum faced by many homeowners: can you put composite decking over wood decking?

This question is more than just a matter of possibility; it's about practicality, safety, and long-term satisfaction. Yes, you can lay composite decking over an existing wood deck, but the decision comes with its own set of considerations.

As we explore this topic, you'll discover the nuances of such an installation, from assessing the condition of your current decking to understanding the implications for your outdoor space.

Our expertise, backed by thorough research and hands-on experience, aims to guide you through making an informed choice about upgrading your deck.

What this article covers:

Can You Put Composite Decking Over Wood Decking?

After putting it to the test and consulting various sources, the short answer is yes, it's possible.

The real question is, should you? According to our research and insights, while you can save time and money initially, there are significant downsides to consider.

Can You Put Composite Decking On A Wooden Subframe?

Placing composite decking on wood frame is doable, but it's not without its challenges. The key lies in ensuring the subframe's condition and strength are up to par.

If the wood is new and pressure-treated, it may well work. However, if it's old and showing signs of wear, it's a risky move.

Factors To Consider When Installing Composite Decking Over Wood Decking

Type Of Wood

The type of wood your existing decking is made from plays a crucial role. Pressure-treated wood can offer a more stable base for composite decking compared to untreated, more susceptible wood types.

Age Of Wood Decking

The age of your wood decking is a vital factor. Newer wood structures might support composite decking adequately, but older, worn-out decks could lead to structural issues.

Levels Of Degradation

Evaluating the level of degradation is essential. If your wood decking shows significant signs of rot or damage, it's a clear indicator that laying composite decking over it might not be the best idea.

How To Check If Your Wood Decking Is Sound

To check if your wood decking can handle composite decking, inspect for stability and signs of rot or damage. Ensure the foundation and joists are in good condition and can support the additional weight of composite decking.

How to Install Composite Decking Over Wood Decking

Step 1: Inspect The Wood Deck

Before considering laying composite decking, inspecting the existing wood deck is crucial. Check for any signs of damage, rot, or instability.

If the wooden decking is damaged, rotting, or unstable, it's highly recommended to rip it up and start anew. This step is vital to ensure the safety and longevity of your new composite deck.

Step 2: Prepare The Surface

Once you've determined that your wood deck is in good condition, the next step is to prepare the surface. This involves cleaning the wood deck thoroughly and making any necessary repairs.

installing composite decking over wood

Ensure that all loose boards are fixed and replace any that are too damaged. A clean and stable surface is key to a successful composite decking installation.

Step 3: Install A Moisture Barrier

Installing a moisture barrier is a critical step when laying composite decking over wood. This barrier helps prevent water from getting trapped between the wood and composite layers, which can lead to rot and deterioration.

The moisture barrier should be laid over the existing wood deck, ensuring it covers the entire area evenly.

Step 4: Lay The Composite Decking

Finally, lay the types of composite decking you've chosen according to the manufacturer's guidelines. It's important to follow these guidelines closely to ensure the decking is installed correctly and safely.

This step often involves measuring and cutting the composite decking boards to fit your deck's dimensions and securing them in place over the existing wood deck.

Pros and Cons of Installing Composite Decking Over Wood


  • Time And Cost Efficient: It's quicker and can be less expensive than building a new deck from scratch.
  • Aesthetic Upgrade: Composite decking offers a modern, low-maintenance finish.


  • Potential For Structural Issues: If the wood decking is not in good condition, it could lead to problems down the line.
  • Moisture Problems: Trapped moisture can cause the wood and composite decking to deteriorate faster.

Should You Install Composite Decking On Top Of Your Wood Decking?

The possibility of installing composite decking over wood decking brings with it a mix of considerations. Technically, it's feasible, but whether it's advisable depends on several factors. The most crucial aspect is the condition of your existing wood deck.

composite decking over existing deck

If the wood is in good shape, stable, and not prone to moisture retention, adding composite decking on top can be a practical solution. However, if the wood deck shows signs of significant wear, rot, or instability, laying composite decking over it could lead to future problems. 

It's essential to remember that the underlying wood structure will continue to age and potentially deteriorate, which could affect the integrity and safety of the composite decking. Therefore, a thorough assessment of your existing deck's condition is imperative before making a decision.

What Should You Do Instead?

If upon inspection, you find that your wood deck is in poor condition, the most prudent course of action would be to replace it entirely. While this might seem like a more labour-intensive and costly route initially, it ensures the longevity and safety of your decking investment.

A new, stable foundation, possibly using modern materials that are more durable and resistant to the elements, will provide the ideal base for your composite decking.

This approach not only enhances the lifespan of your deck but also offers peace of mind regarding its structural integrity.

Additionally, starting afresh allows you to redesign or resize your deck according to current needs or preferences, potentially increasing the value and enjoyment of your outdoor space. Remember, the goal is to create a deck that not only looks great but is also safe and enduring.

can i put composite decking over existing wood deck


While installing composite decking over an existing wood deck is technically possible, it's a decision that requires careful consideration of the wood deck's condition. The longevity and safety of your decking project hinge on the stability and health of the underlying structure.

If the wood deck is in poor shape, replacing it entirely is a more viable and long-term solution, ensuring that your investment in composite decking is sound and sustainable.

At Ovaeda, we're committed to helping you make the best choices for your outdoor space. Our range of high-quality composite decking options is designed to cater to your specific needs, ensuring durability, aesthetic appeal, and value for your home. Visit us to find the perfect decking solution for your home.

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