How to Cut Composite Decking
When considering any decking project it is likely that you are going to have to cut some decking boards to get them to the right dimensions. From jigsaws to chop saws, the thousands of available tools and methods can be confusing.
This guide explains how to cut composite decking safely and cleanly, what tools to use, and the best techniques to ensure accurate results for your decking project.
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Thu, 28 Jul 2026
What You’ll Need to Cut Composite Decking
We recommend using a circular saw for cutting composite decking quickly, efficiently and accurately. You could also use a table saw or mitre saw, but the portability of a circular saw makes it more handy.
It's best to cut composite decking in the morning while the air is cool. The material expands and becomes slightly more malleable as the temperature increases, which can make it more difficult to cut.
Essential Tools
Circular saw (for straight cuts)
Mitre saw (for crosscuts or angled ends)
Jigsaw (for curves and detailed shapes)
Measuring tape and pencil (for accurate marking)
Work bench or sawhorses (to support the board while cutting)
Recommended Blades
Use a carbide-tipped blade designed for composite or fine woodcutting.
Choose a blade with at least 40 teeth for clean, precise edges.
Avoid dull or aggressive blades, they can cause chipping, melting or rough edges.
Safety Equipment
Safety goggles
Dust mask or respirator
Ear protection
Gloves (for handling and stability)
Composite materials produce fine dust particles when cut, so good ventilation or outdoor workspaces are recommended.
How to Cut Composite Decking Boards
Follow these simple steps to achieve clean, professional results:
1. Measure and Mark Carefully
Use a measuring tape and straight edge to mark where each cut will go. Double-check measurements before cutting, especially for starter boards, fascia trims, or stair treads.
2. Support the Board Securely
Place the board on a stable surface, such as a workbench or sawhorses. Ensure that the section being cut extends beyond the support edge to prevent pinching the blade. If possible, use clamps to hold the board steady. Movement during cutting can lead to uneven edges or splintering.
3. Cut Slowly and Smoothly
Ensure the teeth of the saw blade face forward, this prevents chipping and maintains a smooth edge.
For mitre or circular saws, allow the saw to reach full speed before making contact with the board. Apply gentle, consistent pressure, forcing the blade can cause overheating or rough cuts.
Composite decking boards are dense, so patience pays off. Move the saw slowly and steadily through the board, allowing the blade to do the work.
What Blade Is Best For Cutting Composite Decking?
Most of the major saw blade manufacturers will produce what appears to be similar blades across the market. However, the prices may range from £5 to £100 due to differences in quality. These prices are predominantly influenced by design, amount or carbide and the quality of carbide used in the blade.
A 40-tooth alternate top bevel finish blade with carbide tips is best for cutting composite decking boards. We have found that a 40-tooth blade is the perfect balance of speed and accuracy. The carbide means that the blade will maintain its sharpness for a longer period of time.
The alternate top bevel finish blade refers to the tooth configuration on the blade. In this instance this specific configuration makes the angle of the teeth useful for cutting decking material like composite boards, natural wood or veneered plywood.
Why Is The Amount Of Teeth Important?
The amount of teeth on the blade is important to the speed and accuracy of the cut. A blade with a lower tooth count will cut faster but with a rougher finish. Alternatively, the higher the tooth-count on the blade, the slower the cut but the more accurate it will be.
With this in mind, if you choose a blade with a tooth count that is too high then you run the risk of the cut being too slow and burning the material you are cutting. This may be problematic with composite materials that have a high level of plastic.
Which Brand Of Circular Saw Blade Is Best?
We recommend going for one of the more well-known brands such as DeWalt, Bosch or Titan for cutting composite decking. These blades tend to keep their sharpness for a longer period of time. Meaning you won’t have to replace the blade as often.
