When it comes to DIY, Decking Direct know a thing or two about the installation and fitting process associated with composite decking. Unfortunately, we do not offer a fitting service, however this helpful guide has been created for you to follow each step in a simplistic manner without having to spend your budget on a professional fitter.

Our decking experts have compiled all useful installation information into this fitting guide to aid you along in the process of setting up your new deck. From the initial preparation that is necessary to carry out before the fitting process begins, to the installation of the joists and the deck, we will take you through each step all the way through to the finishing touches involving the edging trims.

If you do plan on hiring a professional, we strongly advise against booking a fitter in advance to allow for the successful delivery of your decking beforehand. Please do not hesitate to contact us with any further questions associated with our products and services.



o Allow the decking boards to sit for 24-48 hours in their new environment to allow for them to adjust to the temperature and weather conditions.

o When installing the composite decking, ensure that the weather conditions are mild and dry. We do not recommend laying the decking when the temperature is excessively hot or cold as this can affect the shape and size of the material. 

o Use a wood saw when cutting the decking boards to size and Pozi-screwdriver to secure the screws into place.

o For your safety, ensure you are wearing appropriate clothing when installing
composite decking as well as protective gloves, goggles and a dust mask where

The Joists


Ensure you are working on a flat and stable surface that rests on a slight slope to allow for easy drainage. A 10cm layer of concrete is advised for a solid and level sub-surface.

o The joists can be fixed to the surface by using nail-plugs. Please be aware that drilling pilot holes before hand is strongly advised to avoid any damage coming to the material.


o Leave a 30cm-35cm gap between each joist row on which the decking boards will be laid in the opposite direction. *A 10mm gap between walls or fences and the edge of the decking is advised to ensure successful drainage and room for temperature expansion.*



o Fix a starter clip to the end of each joist. This allows you to decide where to start and finish your decking exactly where you would like. Using a starter clip secure it to the joist by screwing it into place. 

The Decking




o Begin laying your decking working from the inside, outwards. Place and push the first decking board into position and attach it to each joist it crosses over by securing the starter clips.


o Next, you should fit the concealed T-clips into the grooves along the edge of the decking board by screwing them into place along the joists. Use one T-clip per joist. *If you are using plastic T-clips, this will leave a 5mm gap between each board.* *If you are using metal T-clips, this will leave a 2mm gap between each board.*

o Fit the next board by sliding it into the T-clips used to secure the first board and repeat the previous process using another set of T-clips. *At butt-joints – where two ends of decking meet - double up on joists to ensure each board is securely held in place with its own T-clip.*

o Follow this process to install the rest of your composite decking, ensuring there is no overhang and each board is supported.

The Edging


All edging trims can be secured using adhesive or by using screws and a Pozi-driver to form an attachment. However, when securing the edging with screws, take precaution and drill pilot holes into the edging trim beforehand to prevent the material from splitting. Leaving the hidden edge of your decking open will allow for air circulation beneath the decking for satisfactory ventilation.

Skirting Trims

o Measure the edge of the decking and cut the skirting trim to the correct length accordingly. *You can butt two skirting trims together using T-clips.

o Slide the edge of the skirting alongside the exposed edge of the decking board and secure it in place using adhesive or screws.

Corner Trims

o Measure the edge of the decking and cut each side of the corner trim to the desired size using a wood saw.

o Secure the first corner trim to the decking using either adhesive or by screwing it into place. Repeat this along the connecting side.



Bullnose Boards

o With rounded edges, bullnose decking boards have been manufactured to provide a professional, seamless finish for your deck. They are commonly used to install steps onto composite decking.

o Once you have laid the final decking board along with the T-clips on the outer edge, slot the bullnose board into the T-clips. 

o At an angle, secure a screw underneath the decking board into each joist along the length of the decking.

o Optionally, you can install skirting or use a decking board as an edge along the side of your deck for a neat finish. 

Fascia Boards

o For raised decking areas, installing fascia boards will conceal the supporting platform on which your composite decking is laid.

o When using decking boards as fascia, ensure the platform has vertical joists which you can attach the boards to. Measure and cut the board to size and secure them into place using the same T-clip process as you would when installing composite decking horizontally.