How to Cut, Install & Remove Cement Board

Cement backer boards can be cut with a utility knife and straightedge, which creates a straight cut with minimal dust.

1. Place the straightedge on the cement board: Put the straightedge on the cement board along the cut line. Verify that it is straight and secure.
2. Make a score on the board: Change the blade in the utility knife. To make a clean score line, apply pressure to the straightedge and move the knife along it.
3. Turn the board: Flip the board carefully. Use your hands to support it to prevent harm.
4. Make the second cut: Hold the board's smaller side. Turn it 90 degrees, then score again along the line.

Use a powder saw or angle grinder to cut the cement backer board. Make sure they are equipped with a masonry cutting disc. This works faster but produces more dust.

To create less dust while cutting, use a blade with a lower RPM saw made from carbide-tipped to cut the cement backer board.

Take a straightedge and keep it on the board where you want to cut. Use a pencil to draw a clear line along the edge of the straightedge.

Place the saw or grinder on the board at the marked line. Move the saw carefully along the line for a smooth cut.

Use a drill with a carbide-grit hole saw to create round holes in the cement backer board.

Choose where you want the hole. Mark the location on the board with a pencil, making sure the marks are visible.

Take the hole saw and attach it firmly to the drill. Run the drill carefully for a few seconds to ensure it is fixed properly. This prevents the hole saw from loosening while you work.

Place the pilot bit on your mark. Start drilling slowly to ensure a clean cut. When the hole starts forming, reduce the pressure to finish the cut smoothly.

Place the cement backer board sheets to avoid lining up joints. Use a chalk line to mark where to place each sheet.

Apply thin-set mortar with a 1/4-inch notched trowel. Create ridges to help bond the backer board to the subfloor.

Place the cement backer board sheets on the wet mortar. Leave a 1/4-inch gap from the walls and a 1/8-inch gap between the sheets.

Use cement board screws to fasten the sheets. Space the screws every 6 to 8 inches, 1/2 to 2 inches from the edges.

Fill the gaps between sheets with mortar. Use the flat side of a notched trowel and extend it about 1.5 inches on each side.

Cut fiberglass seam tape to length and press it into the joint mortar. Ensure it adheres well and scrape off excess mortar.

With a trowel, apply a thin layer of mortar over the fiberglass tape and leave it undisturbed for 24 to 48 hours.

Use a utility knife to cut any caulk or adhesive around the edges of the cement board. This helps it release from the surface.

Find and take out all screws with a drill or screwdriver. If the screws are stuck, use a bar to help lift the board.

Place the pry bar under one edge of the cement board and carefully lift it. Move around the edges until the board comes loose.

After you remove the board, dispose of it safely. Clear away any leftovers or adhesives from the surface for your next project.