How To Cut Hardy Board: A Step-By-Step Guide

Hardy board, also known as cement board, is a popular material for home construction projects. It is durable, fire-resistant, and moisture-resistant, making it a great choice for areas such as bathrooms, kitchens, and outdoor spaces. However, cutting hardy board can be a challenge, especially for those who are new to DIY projects. In this article, we will provide you with a comprehensive guide on how to cut hardy board.

What is Hardy Board?

Hardy board is a type of fiber cement board that is used as a siding material for homes. It is made from a mixture of cement, sand, and cellulose fibers, which are compressed and cured to form a strong, durable material. Hardy board is available in a variety of sizes and thicknesses, and can be cut to fit any space.

Tools and Materials Required

Before you start cutting hardy board, you will need to gather the necessary tools and materials. Here is a list of what you will need:

  • Hardy board
  • Tape measure
  • Straight edge
  • Pencil
  • Utility knife
  • Circular saw with a carbide blade
  • Dust mask
  • Safety glasses

Step-by-Step Guide on How to Cut Hardy Board

Step 1: Measure the Hardy Board

The first step in cutting hardy board is to measure the area where you need to install it. Use a tape measure to measure the length and width of the space, and then add an additional 1/8 inch to each measurement to allow for expansion and contraction.

Step 2: Mark the Hardy Board

Once you have measured the area, use a pencil and a straight edge to mark the hardy board where you need to make your cuts. Be sure to mark the board on the side that will be facing down during installation.

Step 3: Score the Hardy Board

Using a utility knife, score the hardy board along the pencil lines. Apply firm pressure to the knife and make several passes, gradually increasing the depth of the cut with each pass.

Step 4: Snap the Hardy Board

After scoring the hardy board, hold it along the edge of a table or other flat surface with the scored line hanging over the edge. Apply firm pressure to the board until it snaps along the scored line.

Step 5: Cut the Hardy Board with a Circular Saw

For more complex cuts or cuts that require a straight edge, use a circular saw with a carbide blade. Be sure to wear a dust mask and safety glasses when using the saw. Set the saw blade depth to slightly deeper than the thickness of the hardy board, and then make your cuts along the marked lines.

Step 6: Sand the Cut Edges

After cutting the hardy board, use a sander or sandpaper to smooth the cut edges. This will help to prevent any rough edges from snagging on clothing or skin.


Q: Can you use a jigsaw to cut hardy board?

A: Yes, you can use a jigsaw to cut hardy board, but it is not the recommended method. A circular saw with a carbide blade is a better choice for clean, straight cuts.

Q: Do I need to wear a dust mask when cutting hardy board?

A: Yes, it is recommended that you wear a dust mask when cutting hardy board. The dust created by cutting the board can be harmful if inhaled.

Q: How do I prevent the hardy board from cracking when I cut it?

A: To prevent the hardy board from cracking, be sure to score it several times with a utility knife before snapping it. This will help to weaken the fibers and make it easier to snap along the scored line.


Cutting hardy board may seem intimidating at first, but with the right tools and techniques, it can be a straightforward process. Remember to always wear the appropriate safety gear, and take your time to ensure that your cuts are accurate and clean. By following the steps outlined in this guide, you can successfully cut hardy board for your next home construction project.