How To Install Your Composite Decking

April 2022
Armani Eagle

Composite decking is a very long-lasting and popular choice for homeowners throughout the world. And with good reason, it is very low maintenance and will give stunning results for many years to come.

Different suppliers have different recommendations, so we do recommend checking their installation guides also. However, most composite deck boards are similar to install, and use a hidden faster and starter end clip to secure the boards down.



Start by preparing the ground, ensuring that there is a sturdy base below your decking area. Mark out the area, removing soil if necessary. Ideally, a concrete base of around 100mm thick is poured, or a Type 1 packed hardcore surface. As long as the base won’t sink over time it will be fine. Ensure that drainage is thought about, so that any water drains away and doesn’t pool.

If you think it is necessary, install drains at the lowest point, so that all water won’t sit and soften the surface. This is especially important for wooden subframe, which will rot very quickly, and even quicker if it is sitting in water.

Once you have a solid base, start by creating a perimeter joist of the area. As this is the perimeter, make it as close to the desired finished shape as possible. There are three main materials that are use for composite deck subframes – Aluminium, Wooden, and composite. Wooden joists will not last long (around 5-7 years before they need replacing), and aluminium joists will last the longest, and are the best support for your decking area. They will last 25 years or more.

Not sure what subframe material to go with? Check out the article ‘What is a decking subframe?' This article should help you to understand the best subframe material for your decking area.

Once the perimeter has been created, you will want to begin filling it in with joists spaced at regular intervals. Depending on the board strength and manufacturer, the joist spacing will vary. We recommend joists being spaced at a maximum of 400mm centres, and 375mm as an optimal layout.

Ensure that the joists are supported regularly, and depending on the material used, will need supported differently. Composite and wooden joists will sink over time, so we recommend increasing the support. Different manufactures and supplies again will recommend different support, so contact them for more information. Our aluminium joists span from 400mm to 1200mm depending on the height of the joists. We would always recommend going with the tallest joist possible where possible.

Pedestals are very commonly used to support all types of joists and are a great option as they are adjustable in height and are relatively inexpensive. Sometimes people will use a wooden support post. However, these are susceptible to rot and will not last long as they will almost always be in damp conditions.


Composite Decking

Once the subframe has been installed and correctly supported, you are ready to begin installing you deckboards. There are two main board fixings, direct fix, and hidden fixings. Direct fix can be unsightly; however, some manufacturers have managed to create boards that conceal the holes slightly.


Hidden Fixings

If you don’t want any visible screws, we recommend going for a hidden fastener system. The process may be slightly different from one supplier to another, but in general, it is as below.

Start by installing a starter/end along the perimeter edges where a board will start. Also along any edge where a bullnose edging board will be going. Install them every 300mm-500mm along the edge, ensuring the back edge of the clip is overhanging very slightly so that the board runs flush with the edge.

Offer the first board up, and slide into place. Push against the board slightly, and using a hidden fastener and screw, fix the board partly down. Do not fully tighten the fastener, as you will not be able to get the next board in. Do this along every perpendicular joist, or every 300-500mm.

Once the first row of boards is in place, start the second row, staggering the boards as desired. Push the board into the initial row of t-clips, fix the front edge of the boards using the same method with the fastener, and then fully tighten the clips holding the two boards together to fully fasten the board. Repeat this process across the whole decking area.

Once you reach the end, install starter/end clips along the back edge (the same as the start) and install your last board. Once the last board is slid into place, the hidden fasteners will be difficult to get in, unless you slide them in from one end, and then fix fully.


Direct Fix

When direct fixing boards, start by fixing the first board straight down into the joist below. Avoid over-tightening the board as this could crack the board. Fix at least two screws along each joist, predrilling if necessary. Ensure the correct spacing is left between each board, and expansion gaps are allowed for. Some manufacturers will recommend taking a plug of the decking out where the screw will be going using a specialist tool, which can then be glue over the top of the screw to hide the unsightly finish. This is not necessary, but will help to improve the overall finish quality of the deck.

Still Unsure?

Still not quite sure how to install your decking? Check out our installation guides and YouTube channel for more installation tips and guides.

What Next?

Now that you know how to install composite decking and the subframe, you may be wondering where you can get it from. I’m sure you would have realised by now, but OVAEDA can offer the full package from the ground up, so that you can create your dream deck area.

With so many options available, we know it can seem like a big decision to make. Why not begin by ordering one of our free sample boxes to help you choose which style will best suit you?

You can also call us on 0208 159 2999 or send us an email to to get quotes, guidance and any technical support with your plans. If you think you will require the help of a professional installer, we are happy to recommend one to assist.