One of the most crucial steps in building a deck is preparing a suitable foundation. Without it, the deck will encounter many problems. Not having an excellent foundation can make your deck unstable, unsafe, and most importantly, it can damage the integrity of the deck. The deck won’t also last as long as it should. If you plan to build a composite deck, you’ll have to prepare the ground. But the question is, how can you do it? Here are some tips and guides on how to do it. 

Preparing the Dirt 

One way to build a composite deck is to lay it directly on the ground. However, before you can do it, there are some preparations you need to do. Despite being a superior material, the dirt and grass can present problems for your composite decking later on. Some issues you may encounter are mould, insects, and moisture-related damages. So if you need to build a deck on ground-level dirt, how should you prepare? Here are some instructions that you can follow. 

  1. First, measure the ground according to the measurements of your planned composite decking. You can use some stakes, strings, and paint to mark the location.
  2. Next, remove any plants, rocks, and other debris on the installation area. If necessary, you can use a weed killer to remove any grass and weeds in the area. 
  3. After clearing the ground, dig entire area around 50 mm deep. Make sure to uproot any leftover weed or grass and remove rocks and stones.
  4. After digging, you will need to make sure that the area is level. You can use a piece of a wooden board and a spirit level to check it. You may need to dig more soil, to flatten the area. 
  5. Next, you will have to cover the area with landscaping fabric. It will prevent the growth of grass and weed, which can be damaging to your deck. 
  6. For the next step, you will need to consider how you’ll want to build your deck. One of the options is to lay the composite decking on top of the ground. For this, you will need to fill the area with gravel. Once filled, you will need to make sure that the installation area is still level. You can use a hand tamper to make the surface flat.
  7. Another option is to use concrete slabs instead of gravel. All you will need to do is place the concrete slabs according to the plans of the deck frame. It’s a better choice if you want your deck to be elevated. 
  8. Lastly, proceed to install your decking boards according to the manufacturers’ instructions. 

Preparing a Concrete Slab

how to prepare the ground for composite deck

Another common foundation for composite decking is a concrete slab. Many people have it and are considering adding a deck. While it does make a good foundation, there are still some preparations that you need to do for it to be a suitable ground for your composite decking. Here are the steps that you can follow.

  1. First, you will need to make sure that the concrete slab is in excellent condition. Poorly made concrete slabs tend to sink, along with anything you install on top of it. For this reason, you have to inspect the concrete for cracks and water problems. 
  2. For water-related problems, you will need to use a self-levelling compound. Alternatively, you can use a concrete topping mix, but it usually takes more time. These fixes can also make your concrete to be level. If you find it hard to level your concrete slab, you can also use adjustable pedestals. 
  3. Lastly, pre-drill the screws that you will use for the sleeper system. Most experts recommend that the screws you should use must penetrate at least 1 inch deep into the concrete. When pre-drilling, you’ll also want to drill 1/4 to 1/2 inch deeper than the screws can reach.
  4. Lastly, install the sleeper system and lay down the composite decking boards.