How To Put Down Backer Board For Tile

Backer board is an essential layer between your subfloor and tile installation. It provides a stable, moisture-resistant surface for the tile to adhere to and helps prevent cracking or movement over time. Installing backer board correctly is crucial for a successful tile installation, so follow these steps carefully.

Tools and Materials You'll Need:

Backer board (cement board, gypsum board, or other approved type)
Backer board screws (1 1/4" to 1 1/2" long)
Thin-set mortar
Notched trowel
Tape measure
Pencil or marking tool
Utility knife
Drywall saw
Grout float

Step 1: Prepare the Subfloor

Clean the subfloor thoroughly, removing any dirt, debris, or old adhesive. If necessary, level any uneven areas with self-leveling compound. Ensure the subfloor is completely dry before proceeding.

Step 2: Measure and Cut the Backer Board

Measure and mark the size of the backer board needed to cover the subfloor. Score the backer board along the marked lines with a utility knife, then snap it to break along the score lines. Use a drywall saw for more precise or intricate cuts.

Step 3: Apply Thin-Set Mortar

Spread a thin layer of thin-set mortar over the subfloor using a notched trowel. The notches will help create a textured surface for the backer board to adhere to.

Step 4: Lay the Backer Board

Carefully place the backer board onto the thin-set mortar. Press down firmly to ensure good contact, but avoid sliding the board around, which can disturb the mortar. Butt the edges of the backer board panels tightly together without overlapping.

Step 5: Secure the Backer Board

Drive backer board screws into the backer board at regular intervals (typically 6-8 inches apart). Countersink the screws slightly below the surface of the backer board using a grout float.

Step 6: Fill Gaps and Joints

Mix a small amount of thin-set mortar and fill any gaps or joints between the backer board panels. Smooth the mortar over with a grout float.

Step 7: Allow to Dry

Allow the backer board installation to dry completely before proceeding with the tile installation. This can take anywhere from 12 to 48 hours, depending on the type of backer board used and the ambient temperature.

Tips for Success:

Use a spirit level to ensure the backer board is level in all directions.
Stagger the joints between backer board panels to prevent weak spots.
If using multiple layers of backer board, ensure the joints do not line up between layers.
Protect the backer board from moisture during the drying process.
Follow the manufacturer's instructions for the specific type of backer board you are using.

By following these steps carefully, you can ensure a properly installed backer board that will provide a strong and stable foundation for your tile installation.