How to Install Ceramic Tile Backer Board

Using 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 dimensional 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

In order to install the ceramic tile backer board, you need to know how much backer board you need for the job. With a tape measure, get the exact dimensions of the room. Multiply the length and the width of the room together to get the exact square footage. Then, divide that number by 15, as most backer board comes in 3' x 5' sheets. This will tell you the number of sheets you need to buy. You should most likely purchase an additional sheet or two 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 adhears the backer board to the subfloor, making it stable. Take a trowel and use it to apply some of the thinset to the floor. Spread the thinset around evenly with your trowel. Then, lay a piece of the backer board down into the thinset. Press it down firmly so that the back of the backer board is completely covered with thinset.

Step 3 - Attach

Once you have a piece down into the thinset, you need to attach it to the wood subfloor. You can do this in one of two ways. Some people like to use nails and a hammer or nail gun. Others prefer using a drill and screws. Choose one of the two methods and then fasten the backer board to the sub floor 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 you get to the edge of the room, you will need to cut the backer board to fit. You can do this 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 two pieces beside each other, you need to cover up the seam with tape. This will help protect the seams and cover up the gap between the pieces. For this process, you need to make sure that you are using fiberglass tape and not drywall tape or some other kind of tape.