Composite decking is beautiful, durable, and low-maintenance. It’s one of the best flooring options for backyard living spaces. Because of this, you may have thought of installing one of your old concrete slabs. But the question is, can you lay composite decking straight on concrete? Yes, you can lay or install composite decking on concrete if your want to.

Can You Install Composites Directly on Concrete?

Despite many of its advantages, concrete paving is not the best choice for outdoor living spaces, especially if you aim for a beautiful and luxurious backyard. So you may have thought of installing a composite deck on top of it. But the concern of many is, can you do that without any consequences? 

The answer is it depends. Straight and level ground is one of the perfect places to install a composite deck. However, there are things that you should consider. If the place is not levelled, you may need to use adjustable pedestals to level the installation area. You will also need to solve the potential problem of pooling by making a drainage system.

Of course, sometimes, installing a deck on concrete isn’t a good idea as well. For instance, if the concrete slab has many cracks, it has the risk of sinking, along with the composite decking that you’ll be installing on top of it. Many also don’t recommend laying composite decking on low concrete slabs, as water pooling can be a potential issue. 

How to Install Composite Decking on Concrete

installing decking on concrete

If you decide to install composite decking on concrete slabs, here are some of the general steps to lay them. However, keep in mind any instructions supplied to you by your boards’ manufacturers. 

Before anything else, you will want to check the concrete slab for any potential water pooling issue. You may need to put a slight slope on the concrete slab, away from the house. One means of achieving this is by using a self-levelling compound or using concrete topping mix. You can also caulk the concrete slab, which will prevent it from absorbing water. If you have uneven ground, you will also need to level it first. 

Next thing you’ll need to do is to create the layout for your decking. For composite decking over concrete, you can use a sleeper system. Mark the concrete slab and the corresponding sleepers according to the design and layout of the deck that you want. A more complicated decking will require more, especially if you plan to add stairs and railings. 

After setting up the layout, you’ll want to pre-drill concrete screws for the sleeper system. Drill the screws at least 1 inch in depth. Many also advise pre-drilling at least 1/4 inches deeper than the screw can reach, making it easier to drive them. 

Next, start installing the sleeper system. For a good outcome, you will want to use water-resistant materials. For composite decking, many recommend using at least pressure-treated wood. The sleepers should at least be 1 1/2 inches in height and width. While you can follow the concrete slab’s slight slope, you can also use spacers to level it. Secure the sleepers in place by drilling them into the slab carefully. 

Lastly, install the joists of the sleeper system. The joists should be parallel to the slope of the concrete slab. You’ll also need to space the joists apart according to the manufacturers’ instructions. For most cases, you’ll want at most 16 inches on centre for joists spacing. 

After installing the sleeper system, you have the option of further protecting it from water by using flashing tape, especially if you’re using common grade lumber. But if you’re using water-resistant materials, this step is not necessary. 

You can finally install the composite decking boards. Follow the directions supplied to you on how to do it. 

Use Composite Decking Tiles

Another way of installing composite decking on concrete is by using composite decking tiles. For this, you will still need to level and water-proof your slab. However, installing it is easier, as you can lay them on the surface straight away. You may need a saw to cut the tiles according to the shape of the layout of your planned deck. 

Conclusion

Can you lay composite decking straight on concrete? Yes, you can lay or install composite decking on concrete if your want to. Composite decking is beautiful, durable, and low-maintenance. It’s one of the best flooring options for backyard living spaces