How to Cut Fibre Cement Decking

Cutting fibre cement decking is a task that requires precision, safety, and the right tools. This comprehensive guide will walk you through the process, ensuring a clean, efficient, and safe operation.
Fibre cement decking, known for its durability, fire resistance, and aesthetic appeal, is a popular choice for many homeowners and builders. However, cutting it can be challenging due to its hardness and the dust it produces.
Here’s a step-by-step guide to help you master the art of cutting fibre cement decking.

Safety First

Before you begin, prioritize safety. Fibre cement dust can be harmful if inhaled, so it's essential to wear appropriate safety gear. This includes:
  1. Dust Mask or Respirator: Choose a high-quality mask or respirator to prevent inhalation of fine dust particles.
  2. Safety Goggles: Protect your eyes from dust and debris.
  3. Ear Protection: Cutting fibre cement can be loud, so use earplugs or earmuffs.
  4. Gloves: Wear sturdy gloves to protect your hands from sharp edges.

Tools You'll Need

Selecting the right tools is crucial for a successful and smooth cutting process. The most commonly used tools for cutting fibre cement decking include:
  1. Circular Saw: The generally accepted method for straight cuts on fibre cement decking is using a circular saw. When choosing a blade, it is important to use a Polycrystalline Diamond (PCD) circular saw blade, usually with 4 or 6 teeth. Standard carbide blades, while capable of cutting fibre cement, dull extremely fast, making them less effective and can result in warping and overheating the blade.
  2. Measuring Tape and Carpenter's Pencil: For accurate measurements and markings.

Preparing to Cut

Before you start cutting, proper planning and preparation are key.
  1. Measure and Mark: Accurately measure the area where the decking will be installed. Use a carpenter's pencil to mark where cuts are needed on the fibre cement board.
  2. Support the Decking: Lay the fibre cement board on a stable, flat surface. Ensure it's adequately supported along its length to prevent breakage.

Cutting Technique

For straight cuts, use a circular saw. Align the saw blade with your marked line and cut in a steady, controlled manner.

Managing Dust

Dust management is crucial when cutting fibre cement decking. Dust from fibre cement, also known as Silica Dust is an incredibly hazardous substance that should not be inhaled if at all possible.
You can reduce exposure in two ways:
  1. Make sure you are wearing a respirator whenever cutting fibre cement material; and
  2. Use a dust extractor on the circular saw to collect the dust through a vacuum.
  • Always cut fibre cement decking in a well-ventilated area, preferably outdoors.

Finishing Touches

After cutting, you'll need to make some finishing touches:
  1. Smooth Edges: Use a sanding block or an orbital sander to smooth any rough edges.
  2. Cleaning: Clean the cut area with a brush or a damp cloth to remove any remaining dust.

Installation Tips

Once your pieces are cut, you're ready for installation. Remember:
  1. Follow the Guide: Adhere to the installation guidelines. Read our
    fibre cement installation guide
  2. Use Recommended Fasteners: Use the clips that are specifically designed for fibre cement decking.


Cutting fibre cement decking requires attention to detail, adherence to safety protocols, and the right tools. By following this guide, you can achieve professional-looking results while maintaining a safe working environment. Remember to measure twice, cut once, and always prioritize safety.

Maintenance and Longevity

To maintain the longevity of your fibre cement decking:
  1. Regular Cleaning: Keep the decking clean from dirt and debris. For more information read our
    fibre cement care guide
  2. Periodic Inspections: Regularly inspect for any signs of damage or wear.
By following these guidelines, your fibre cement decking will not only look great but also last for many years, making it a valuable addition to your home or building project.