Composite decking offers a durable and low-maintenance alternative to traditional timber, making it an increasingly popular choice for UK gardens. While professional installation is recommended for the best results, many homeowners choose to fit composite decking themselves with some basic DIY skills and the right tools. This guide will take you through the essential steps for fitting composite decking, helping you create a beautiful and long-lasting outdoor space.
Preparing the Site
The first step is to prepare the area where you plan to install your composite decking. Clear the space of any existing decking, plants, debris or obstacles. Ensure the ground is level and firm, as a stable base is crucial for a lasting deck. If necessary, excavate soil to create a flat surface and add a layer of compacted hardcore or sharp sand to improve drainage.
Once the base is prepared, lay a weed membrane to prevent unwanted growth beneath your deck. This will help keep the area tidy and reduce future maintenance.
Building the Substructure
Composite decking requires a solid substructure, usually made from pressure-treated timber or composite joists designed to resist rot and weathering. Begin by marking out the deck’s dimensions and positioning the joists at regular intervals, typically 400mm to 600mm apart, depending on the manufacturer’s recommendations.
Secure the joists to the ground using concrete piers, adjustable deck supports or ground spikes to provide stability and keep the timber off the soil, which helps prevent moisture damage. Make sure the subframe is perfectly level and square using a spirit level and tape measure before proceeding.
Laying the Decking Boards
Start laying your composite decking boards along the longest edge of the deck for the most appealing finish. Most composite decking boards come with a groove on the sides to accommodate hidden fixing clips, which create a clean surface without visible screws.
Attach the clips to the joists according to the manufacturer’s instructions, usually by screwing them in place. Then, slot each board into the clips, ensuring a small expansion gap of about 5-8mm between boards to allow for natural movement caused by temperature changes.
For the first and last boards, you may need to pre-drill and screw them directly into the joists to secure the edges firmly.
Cutting and Finishing
Cut boards to fit the shape of your deck using a fine-toothed saw or a circular saw with a blade suitable for composite materials. Take accurate measurements before cutting to ensure a neat finish.
Once all boards are laid, install fascia boards around the perimeter of the deck to cover the edges of the substructure. This gives your decking a polished and professional appearance.
Maintenance Tips
Composite decking requires minimal maintenance but regular cleaning with warm soapy water helps keep it looking its best. Avoid abrasive cleaners or power washing at high pressure, which can damage the boards.
Check periodically for loose clips or screws and tighten as necessary to maintain a safe and stable deck.
In Summary
Fitting composite decking involves careful preparation, constructing a solid substructure, and correctly installing the decking boards with the recommended spacing and fixing methods. With patience and attention to detail, DIY installation can result in a beautiful, durable deck that enhances your outdoor living space for years to come.
