Durock cement board is a mold-resistant panel used under tile and other finishes for both interior and exterior applications. It comes in 3-by-5 foot sections. Durock easily installs directly to the wood and steel framing with cement-board screws. It does not rot, swell, decay or disintegrate. When installing Durock cement board there are almost always cuts to be made. Cutting Durock is similar to cutting drywall. With only a few tools, you can have your Durock cut and installed in no time.
Measure the opening on the wall or floor where the Durock will go. Run a tape measure from one side to the other for both the length and width and record both measurements.
Mark the Durock at the proper cut marks for the length and width. Lay a T-square down on the Durock. Run a utility knife along the edge of the T-square. Push down firmly on the knife to score the cement board. Run the knife back and forth along the same line.
Remove the T-square and grip the Durock on both sides. Snap it in two and line up the T-square for the next cut. Score the Durock just like the previous step and snap it into two pieces.
Smooth out the edges of the cement board with a rasp. Grip the rasp in your palm and move it back and forth over the cut edges of the Durock.
Place the Durock into the opening and verify that it fits. Cut all of the remaining Durock to size with the utility knife.