Man cutting composite wood boards

A guide to cutting composite decking

If you’re installing your composite decking yourself, one of the most important steps in the installation process is the cutting of the boards. Read on for a guide on how to cut your boards correctly and what tools you’ll need.

What saw and saw blades are needed to cut composite decking?

One of the key tools you’ll need to cut your composite decking is a saw. It may sound obvious, but the quality of saw will affect the overall finish of your decking. For example, choosing a saw with a high tooth count, with blades that remain sharp, and one that doesn’t overheat will all result in a clean, sharp cut. We’ve looked at the types of saw you could use in more detail below.

Saws and saw blades

Hand saw

You can use a traditional hand saw to cut your composite decking, but it’s not the most efficient option. There’s also the risk of movement, even if your board is clamped to a table, which can affect the straightness of the cut.

Circular saw

A circular saw is a handheld saw which uses a revolving motion to cut. When using a circular saw it’s important to clamp the board you’re cutting to a worktable to avoid movement.

Table saw

A table saw is the same as a circular saw, but it’s fixed. Rather than pushing the saw through the board, as with a circular saw, the saw is set within the table and the board is pushed through the blade, offering more control over the cut.

Mitre saw

A mitre saw is set on a pivoting swing arm which you pull down onto the board. This saw allows you to accurately cut angles very quickly.


A jigsaw enables you to accurately cut angles and shapes. This makes it perfect for cutting composite deck boards that need to go ‘around’ something, such as drainpipes, steps, or drains.

Other tools needed

Other tools you’ll need to install your decking include:

  • A tape measure
  • A set square
  • A pencil or chalk (test the chalk first to ensure it will not make a permanent mark)
  • PPE such as eye protection and a dust mask

Steps to cutting composite decking

1. Preparation

Make sure you work in a well-ventilated space and wear the necessary PPE, such as protective goggles, a dust mask, and ear protectors if the saw you’re using is loud.

Next – prepare your composite boards. Ensure they’re clean and have been stored in a dry place. You now need to ensure the edges of the board are straight.

2. Measuring and edging

Measure the board length based on the measurements of your sub-structure and mark the measurement on the board. Allow additional length so the board overhangs the sub-frame. This will allow you to cut it down to size, rather than cutting it too short and wasting a deck board. It’ll also help you create a flush finish.

Man measuring composite decking joists before cutting

3. Cutting and types of cut

Once the boards are measured, you’re ready to cut.

Types of cut

There are a number of types of cut that you’ll need:

Straight cut – this is the most used and straightforward cut, especially if your new decked area is square or rectangle in shape.

Angle cut – you’ll need to use this cut if your deck features a diagonal pattern or edge. If you use a mitre saw these cuts are as easy as a straight cut – just remember to measure accurately!

Curved cut – curved shapes can be cut using a jigsaw. Again it’s important to measure accurately before you cut.

4. Installing the boards

Now your boards are cut, they’re ready to install. It’s important to always follow the manufacturer’s instructions. When fitting our boards, please download our step-by-step installation guide – there’s one for every decking collection. Following these will ensure a professional finish.

Cutting composite decking best practices

  • Always use the appropriate PPE to protect yourself and your surroundings.
  • Prepare your boards to ensure the cleanest cut.
  • Measure twice and cut once! This may sound simple, but it’ll save a lot of time (and money) in the long run.
  • Choose the most appropriate saw for the cut you require.
  • Always read the manufacturer’s instructions.

How Ecodek can help with your composite decking needs

If you’re unsure of where to start with a new decking project, call our friendly, knowledgeable team today on 01978 667 840 and they’ll guide you in the right direction.

Advice & how to, Installation support