Replacing Wood Deck Boards With Composite

Despite the longevity of a deck's structure, the surface boards on it still do tend to wear down. This has led many people to wonder whether wooden deck boards can be replaced by composite deck boards with no alteration to the existing deck structure.

The Installation of composite deck boards requires some preparation, however with planning you can install composite decking over existing deck structures in a cost-effective manner while making sure that everything is up to code.


There are numerous advantages to replacing wooden deck boards with composite deck boards with the most prevalent advantage being much lower cost to maintain. Since composite deck boards do not require sanding or stain like wooden deck boards, it requires much less maintenance as compared to wood. Additionally, with the possibility of installing composite decking over existing decking, it is far more cost-effective than replacing the entire installment. For patchwork over damaged wooden decks, it is much easier to install composite decking over wood and it can add value to your home.


Can composite decks be placed directly over wooden boards?

No, installing composite decks over wooden boards is not a recommended practice. Usually, Joists are replaced or capped during decking replacement as there is usually dry rot beneath the decking where the joist is penetrated by the fastener. The old decking should be removed so that the joists and beams can be assessed for damage and repaired if needed.

For a longer-lasting deck, installing decking over old decking is not recommended as it reduces the lifespan of the material. The reason being the gaps and joints between the two different layers of materials will trap water in it further degrading the decks and causing damage to the decks. The contact area needs to be limited to only the top of the joists, leaving exposure on both sides. With two decking on top of each other, there is little to no exposure meaning no drying potential beneath the decking. With stagnant water comes rot which will damage and decay both the new and old decking. It may also void the warranty of over-the-counter solutions such as prefabricated decking as installations over old decking or solid surfaces are prohibited.

How much does it cost to replace a wood deck with composite?

Before a new deck is installed, the old surface would need to be removed. The average prices of these removals are in dollars/square feet of area with it being in the range of $5.00-$10.00 per square foot, replacing composite decking typically costs anywhere between $3.00 and $12.00. Replacing entire deck boards with composite decking typically costs between $8.00-$22.00 per square foot which is assuming that it is a DIY job when it comes to the installation of the decks.

Keep in mind, the installation cost is dependent on the amount of area that needs to be replaced, so the more the area that needs to be replaced the higher the costs.

How to install Composite Decking over Existing Decks.

You can install composite decking over an existing deck in three easy steps.

Step 1: Remove the current deck boards.

Begin removing the unwanted boards by drilling, using a hammer, or using a pry bar. Damaged sections may need to be dislodged with a circular saw or chisel.

Step 2: Check Joists for damage

Use a screwdriver to probe around for soft spots and loose fasteners where the decking would come into contact with the substructure. Before resurfacing your wooden deck with a composite deck make use of a chisel to treat smaller areas of damage. To make sure your joists are protected against moisture or rot consider using a protective joist tape to prevent moisture penetration by sealing joist fasteners.

Step 3: Installing the composite decking

Make use of 3” decking screws to connect the new boards with the joists. You can also deploy a discrete fastener system that keeps the boards tightly sealed against their supporting substructure and joists.

To make sure that you’re doing it correctly from everything between inspecting the frame and the substructure or placing the new boards correctly and securing them in their place over the joists. Before proceeding further it is worth learning more about deck resurfacing and how to install a composite deck over a wooden frame.


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