ARDeck composite decking is easy to fit and can be fitted by most DIY enthusiasts! Before you decide to fit, make sure you have taken into account where you want your decking to be, taking into consideration which parts of your space get sun light and if you want to be sat in the sun or shade predominantly. 

In this guide, we’ll explain how to install composite decking step by step, including the tools you need, how to build a subframe, and how to correctly fix decking boards for a long-lasting finish.

Tools and Materials Needed

Before starting your composite decking installation, gather the following tools and materials.

Tools

Tape measure

Spirit level

Power drill or impact driver

Circular saw or mitre saw with fine tooth blade

Rubber mallet

Pencil or chalk line

Materials

Composite decking boards

Composite clips

Stainless steel screws

Treated timber or composite joists for the subframe

Weed membrane

Step 1: Prepare the Ground

The first step when installing composite decking is preparing a stable base.

Remove any grass, soil or debris from the area

Install a weed control membrane to prevent weed growth beneath the decking

Create a solid base using paving slabs, concrete pads or compacted gravel.

Good drainage is essential. Always ensure the ground slopes slightly away from buildings to prevent water build-up.

Step 2: Build the Decking Subframe

The decking subframe is the structural support that holds the decking boards.

Most installations use pressure treated timber joists, although composite joists are also available.

Important guidelines:

Joist spacing should be 300–400mm apart maximum. 

Ensure the frame is square, level, and secure

Allow a small fall of 1–2mm per metre to help water drain

A properly installed subframe is critical for a strong and long-lasting deck.

Step 3: Install First Clips

Unlike other composite decking, ARDeck doesn't need starter clips, we just use one style of clip. 

To install your first clips:

Fix the first clips along the edge of the frame

Position them so that the board sits flush with the edge

Secure clips with screws

Step 4: Lay the First Composite Decking Board

Slide the first composite decking board into the starter clips.

Make sure the board is:

Straight and aligned with the frame

Securely positioned within the clips

Installed with a 5–8mm expansion gap against walls or structures

Composite boards expand slightly with temperature changes, so spacing is important.

Step 5: Continue Installing Decking Boards

Repeat the process across the entire deck area:

Insert hidden clips

Secure them to the joists

Slide the next board into position

Always check boards remain straight and evenly spaced as you work.

Step 6: Fit the Final Decking Board

The final board can be installed using finishing clips or colour-matched face screws.

Before securing the board:

Check alignment

Ensure the correct expansion gap is left

Make sure the board sits flush with the deck edge

Step 7: Install Edge or Additional Boards 

Our edge steps complete the installation and hide the subframe. Or you could use another decking board side-on. The choice is yours!

These steps:

Cover exposed board edges

Improve the overall appearance

Provide a professional finish

Step 8: Enjoy Your Decking!

Check out our blog with ideas on what to do with any left over decking, cleaning tips, inspiration and more!