Can I put composite decking over the existing wood deck?

decking installation

Composite decking over the existing wood deck


A composite deck can easily be used to cover the existing wood deck if an old deck is strong and sound; it can’t be torn down. Those that have built a deck before will understand how difficult it is to accomplish it. 

You only need to remove the affected part and replace it with new ones. In this write-up, you will know how to replace the worn decking with low maintenance composite materials. And we will also show you how to determine if your deck is still in good structural shape. But to get work done, you need to keep all your carpentry tools such as saw, screw gun, square, sledgehammer, and pry bar ready for the work.

The ways of adding composite decking over existing wood deck

 To add a composite decking over a wood deck, you will make an underground provision to enable it to carry the additional weight by adding beams. In some decks, you need to make a beam with a frame of 16-24 inch spacing between the beams. 

And for the installation of this beam, you need hangers for the new framing members. You can gently slide them under or underneath the decking. The joist hangers have to be squared with the rim, and this will help to the other side, open to accept the beam. 

Use the same existing joists and put it underneath the deck after cutting them into the same size. Adjust the loose side of the hanger by adding it up with the new one. Then concatenate both the loose side and the new side to the rim joist. You need to join the existing deck boards with the new joist with two screws. When you examine the deck and notice another problem, endeavour to add nails to strengthen the weak deck.

Check out the angles and joint hangers and fix well the loose bolts, nails, or screws. Start from one side of the deck to keep your boards. Your composite decking should be laid perpendicular to the existing deck so that it will not stop covering the gaps that exist between the boards. This will make the moisture to go off. 

Make 16 to 24 inches with two screws down the decking. Ensure that you keep the board rows straight and keep them in 90 degrees position with a quick square from the existing wooden deck. Cut out right length so that you can be able to cut off the unnecessary part. 

The length piece should be attached to the deck, and the overhang ones will be cut off with a circular saw. The cut-off piece will serve as a support between the board end.  

composite decking installation with wood

How to check if your deck is sound

There are things you need to consider when deciding to change your deck.

  1. Sound footings: when you notice heave above the normal in your footings, you need to support it with deeper ones. You should not remove the old one; rather, you dig and add the new one.
  2. Wood condition: always check the posts and other framings to see if they are of treated materials. The treated woods can last more than non-treated ones. It is very dangerous to frame your deck with cedar or redwood because your wood will not last long. When you notice that your screwdriver penetrates punky or softwood, it is a clear indication of rot, and you need to start all over from scratch. You can experience this rot when the post has contact with the footing or ground. 
  3. Structural integrity: in making a plan of your deck, it is pertinent to make a list of the sizes and spans of the beams and joists. You can do that to look out for any building department in your city hall. Never rely on your measure. Ask the inspector to confirm the structural size and spans of your deck. 
  4. Details: in each of every pair of joists, there will be 3/8-in. lag screw or bolt into the ledger for a solid connection. 
Tags: deck board, decking, laying deck boards

Leave a Comment

Shopping Cart