The snapped edges of the backer board will be rough, but you can smooth them with a rasp. Using Power Tools There are a few different power tools that you can use to cut cement backer board.

Step 8: For holes more than a few inches wide, use a carton knife or carbide-tip tool to cut back the cement board and expose a stud on either side of the damaged area. Cement board contains silica.

and cement board. Outside of pictures on the site showing it being used on wood, no official Ryobi source recommends using the cut-off tool on wood. But if cut-off tools from brands such as ...

A cut off tool has a 3-inch diameter spinning disc blade at the end of a handle. It's made for one-handed operation to cut metal pieces, tile, cement board, or plastic in a compact space.