Dos and Don’ts of Composite Decking Installation

Everyone loves a backyard deck. It’s a great place to relax in the sun, to enjoy family barbecues and to make the most of your outdoor space. A quality outdoor deck will create a seamless transition from your indoor to outdoor areas and, if done right, can even increase the value of your property.

If you’re considering a backyard decking project, one of your foremost considerations should be your choice of decking material. The two most common decking materials are treated timber products and composite decking.

Composite decking is a great alternative to timber. It’s long-lasting, requires minimal maintenance compared to timber and it’s specifically designed to stand up to Australia’s tough weather conditions.

If you do decide to go with composite products, it’s worth noting that there are some differences when it comes to working with and installing composite decking.


Also Read: 4 Things to Consider Before Starting a Decking Project


The best composite wood decking boards are made from a mixture of reclaimed timber and recycled plastics. Compared to timber, composite materials are different to work with and behave differently when exposed to the elements. So, it you’re looking to install a this kind of deck, you need to right tools and a clear understanding of the dos and don’ts of composite decking installation.

Composite Decking

Use the right tools for the job

Any DIY project will only be as good as the tools you use. While composite boards may look like timber, they are not timber. They are harder and denser than regular timber due to the plastic content. That means you need saw blades specifically made to handle composite boards.

Using saw blades designed for timber might be fine for the first few cuts, but generally they will quickly go blunt before the job’s end. For that reason, we recommend using the appropriate composite-cutting blade for your application.

You should also never use a nail gun on composite products. Nail guns tend to cause splitting and cracking in composite boards. Nails also aren’t a reliable method for securing the boards as the expansion and contraction can work the nails loose over time. Instead you should always use stainless steel or galvanised screws. Holes should be predrilled and pre-countersunk. Drilling will ensure the boards don’t split and countersinking means the boards won’t mushroom over the screw heads.

Leave expansion gaps

Temperature changes cause composite boards to expand and contract along the length of board. As a result, you need to leave gaps between the ends of the boards during installation.

You should be aware of the temperature during installation. If you are installing the deck on a hot day the boards will have already expanded, so you should keep the gaps between the boards small. When the temperature drops and the boards cool, the gaps between the boards will open up.

It is important to understand how composite decking boards behave to ensure your gaps aren’t too big or too small.

Don’t cut the boards at different times of the day

Due the tendency of the boards to expand and contract, you should aim to cut all the boards at the same time. If you are cutting boards at different times of the day when the temperature is different, you will find they will be different lengths. To avoid this, it is recommended to layout your deck, fasten the boards with a slight overhang then trim them at the same time.

Leave adequate ground clearance

As with any decking project, it’s important to leave ample ground clearance. Having a clear space beneath the deck allows for airflow, which helps to cool the boards during warm weather. Ground clearance is also vital to ensure that the decking isn’t in contact with ground moisture. For most brands of composite decking boards, manufacturers will specify the necessary ground clearance as part of the product warranty.

Like any DIY project, understanding the materials and using the right tools is vital to get the results you want. And composite boards are no different. However, if you follow the product instructions, you should have no problem and come out with a great deck that will last years to come. Read more Decking Blogs Here >>