Home Repair and Paint Guide

... On floors, the cement board is attached to the sub-floor material. Make sure the floor is solid and does not flex under load. This is especially true for kitchens where large appliances are installed. Refrigerators are especially problematic because they are rolled into place, heavy, and occasionally moved so the floor can be cleaned. Cement board can be cut with a circular saw driving an abrasive blade, but that creates a ton of dust and can damage the saw motor. It’s better to score the backer board with a hand tool that has a carbide tip. Make several passes along the cut line, and then apply pressure to the other side of the cement board along the scored line. It usually snaps the backer board in two along the scribed line. Cement backer board can be screwed or nailed to the wood framing. Always follow the instructions provided by the manufacturer. Screws are best because they hold tight and don’t loosen over time. Make sure that the screws or nails are corrosion resistant. Leave about a 1/8 inch gap between the boards and fill this gap with silicone caulk. Never install the board with an edge directly touching something like a bathtub rail because water can get into the board and destroy it. Instead, leave a 1/8 inch gap between the tub rail and cement board edge and fill the gap with silicone caulk. Allow the caulk to cure thoroughly and then start applying the ceramic tiles. If you took your time and made sure everything is flat and plumb, the tile installation should go smoothly with a very satisfying result ...