Cutting Cement Board: Tips for Clean Edges

Cutting cement board is an important skill proper tackling home renovations involving tiling, drywall replacement, or waterproof installations in areas like bathrooms or kitchens. Cement board is a tough, water-resistant material made of cement and fiberglass mesh. Its rigid nature causes it to be ideal as a tile backer but also requires special care when cutting. Unlike regular drywall, cement board can dull tools quickly and generate harmful dust or even handled properly. Before you begin, it's important to really have the right tools and safety gear. Common tools for cutting cement board add a carbide-tipped scoring knife, circular saw with a cement board blade, utility knife, jigsaw, or angle grinder. Safety goggles, gloves, and a dust mask or respirator are important to protect yourself from airborne fibers and debris.

The most straightforward method for cutting cement board is the score-and-snap technique. Begin by marking the cut line with a pencil and a direct edge. Utilizing a carbide-tipped scoring knife or an electricity knife, firmly score across the line several times to create a deep groove. Once adequately scored, place the cement board over a firm surface such as a workbench with the groove aligned at the edge. Apply downward pressure to snap the board cleanly across the line. While this approach is best suited for straight cuts on thinner boards (typically ¼ inch), it's efficient, produces minimal dust, and requires fewer power tools—ideal for small projects and DIYers.

For more complex cuts, such as for instance curves or holes for plumbing and electrical outlets, power tools like jigsaws, rotary tools, or angle grinders may be necessary. A jigsaw fitted with a carbide-grit or diamond-grit blade is particularly helpful for cutting shapes or curves. If you're using a circular saw for straight cuts, go for a blade created specifically for fiber cement board to prevent rapid wear and excessive dust. When working with power tools, always cut outdoors if possible or use dust control methods like a vacuum attachment. Wetting the board lightly before cutting also can reduce airborne particles. You need to be mindful never to soak the board, as excessive moisture can compromise its integrity  How to Cut Cement Board.

After cutting, edges may appear rough and require light sanding with a masonry sanding block or rasp to eliminate splinters or unevenness. This ensures an improved fit and cleaner finish, especially in visible areas. Clean off any dust and debris before installation to promote better adhesion if you're applying thin-set mortar or tape. When attaching cement board, always follow the manufacturer's guidelines, using corrosion-resistant screws and spacing them correctly. Remember to leave a small gap between sheets to allow for expansion and contraction. Properly cutting and installing cement board not merely ensures structural durability but in addition enhances the longevity of one's tiling or wall finish.