Do You Need Foundation For Composite Decking?

Composite deck board

Do you need a foundation for composite decking? Pretty much all structures require a foundation to support them. So does composite decking need foundations? Yes, they do need foundations. However, you don’t need to set up an elaborate foundation for deck building. There are two ways to build a deck, and how you prepare the foundation slightly differs depending on which one you choose. You can either go for a ground-level deck or an elevated deck. Here is how you set up the foundation for both of them.

Foundation for Decks Directly on Top of Soil

Ground-level decks, or decks installed directly on top of the ground, are one type of decking. How do you prepare the foundation? First, you will need to determine the area where you will be building the deck. You can use some lines and pins to mark the area. 

Next, start clearing the area of plants, rocks, and debris. You may want to mow the land to remove the grass. Then, dig around 40-50 mm, removing leftover turf, if any. Make sure that the ground is even. You can use a tamper or any flat surface to spirit level tool to check whether it’s flat. 

After that, cover the area with a piece of landscaping fabric. The fabric will help stop the grass from growing within the foundation. Why is this important? Overgrown grass can damage your deck. Then cover it with 40 mm to 50 mm gravel. The gravel will help drain the moisture away from the frame of the patio. You can use wood chips, stone pebbles, and other similar materials in place of gravel. 

Foundation for Floating Decks 

Floating decks are similar to decks built directly on top of the ground. The difference is that it uses concrete pads to elevate the decks off the ground. Because of this, the deck is less likely to get damaged by moisture.

Preparing the foundation for this type of deck follows the previous one. You’ll need to clear the area, dig, and level it. You may also want to lay landscaping fabric and gravel on the area. Then, you will need to carefully place concrete pads or concrete blocks to elevate the frame off the ground. The arrangements of the blocks will depend on the layout of your patio.  

decking with good foundation

Decks Using Posts

Another way to build a deck is to use posts and footings as the foundation. First, you will need to locate where you will need to put each footing. Mark them on the ground for digging. For this, you can use spray paint.

After marking, dig the area using a shovel or other digging tools. Make sure the area is dug through the proper depth and size. The excavated area should also be free from loose soil. Then, set the cardboard tubes to prevent the holes from collapsing. 

Next, mix concrete with a shovel. Pour the mixed concrete into the tubes to fill it. Then, install the anchor bolts on the tubes and let them harden. You may have to wait for at most five days for the concrete to harden fully. Then install the post base according to instructions. 

There are other ways to set posts for your deck. Another way is pouring concrete directly on the post hole, sticking in the post, and filling it with gravel. Whatever method you choose, make sure that it adheres to local building codes.

Building the Frame of the Deck

The frame can be considered as the foundation of the deck. After determining whether you choose a ground-level or elevated deck, it’s now time to start building the frame. The process involves setting up beams and joists. How to build will slightly differ depending on the type of deck that you chose. You can find some guides on how to build one. 

After setting up the foundation, it’s now time to install the composite decking materials. You can also build some stairs and add some accessories to the deck. After that, you can now enjoy your beautiful deck.

Tags: decking, decking foundation, foundation

Leave a Comment

Shopping Cart