Backer board is an essential part of installing ceramic tile over a wood subfloor. Without backer board, you cannot install the ceramic tile because the wood subfloor does not have enough stability to support the tile. The tile will break and crack if you do not use the backer board. Here are the basics of how to install ceramic tile backer board effectively.
Step 1 - Estimate
Use a tape measure to determine the exact dimensions of the room. Multiply the length and the width of the room to get the exact square footage. Then divide that number by 15, as most backer board comes in 3x5-foot sheets. This step will determine the number of sheets you need to buy. You should most likely purchase an additional sheet or 2 so that you have enough for waste.
Step 2 - Apply Thinset
When you are ready to install the backer board to the wood subfloor, you need to first apply thinset. Thinset is the adhesive that you will also use to install the ceramic tile. It adheres the backer board to the subfloor, making it stable. Use a trowel to apply thinset to the floor. Spread the thinset evenly with your trowel. Then lay a piece of the backer board into the thinset. Press it firmly so that the back of the backer board is completely covered.
Step 3 - Attach
Once you have a piece down, attach it to the wood subfloor. Some people like to use nails and a hammer. Others prefer using a drill and screws. Choose a method and fasten the backer board to the subfloor with a screws or nails. Some people are tempted to only put a few screws or nails into the holes. Set a nail or screw every 8-inches around the perimeter of the board, 2-inches from the edge.
Step 4 - Cutting the Backer Board
When reach the edge of the room, cut the backer board to fit. Do so with a circular saw. Measure the size that you need and then cut the appropriately sized piece and put it in the opening.
Step 5 - Finishing
Continue filling the floor with backer board in this manner. When you put 2 pieces beside each other, you need to cover the seam with tape. Doing so helps protect the seams and cover the gap between the pieces. For this process, you need to make sure that you are using fiberglass tape and some other kind of tape.