How to Lay Concrete Backer Board
Concrete backer board is a stiff board that is made from concrete, sand and fiberglass. The backer board is mainly used as a foundation for laying tile over plywood or concrete subfloors. A flat surface makes the best surface for laying tile. Backer board makes that surface flat so the tile can adhere better. It can be used for the floor or wall.
How to Lay Concrete Backer Board
Materials Needed
- Tape measure
- Pencil
- Straightedge
- Utility knife
- Mortar
- Screws drill
- Thinset mortar
- Margin trowel
- Fiberglass tape
- Straight trowel
1. Take measurements of the area that the backer board will cover.
2. Use a pencil to make the measurements on the rear of the backer board.
3. Place a straightedge along the pencil mark.
4. Score the backer board along the straightedge using a utility knife.
5. Turn the backer board over and score that side also.
6. Place one hand on the side of the line. Lift the edge of the backer board with the other hand to snap it at the line.
7. Mix the mortar according to the directions on the package.
8. Use a trowel to spread the mortar on the floor. Start at one wall and use only enough mortar to cover one small area at a time.
9. Place the backer board on the mortar. Leave 1 inch between the backer board and the wall.
10. Spread more mortar and place the concrete backer board until the floor is completely covered.
11. Drive screws into the board and through the floor using a drill. Leave 4 ½ inches from the end of the backer board. You can also follow the screw pattern printed on the back of a piece of backer board. Apply screws at the top, side and bottom of the backer board.
12. Apply thinset mortar between the joints of the backer board. Use a margin trowel for this step.
13. Apply fiberglass tape over the thinset mortar.
14. Use a straightedge trowel to apply another layer of thinset mortar over the fiberglass tape.
15. Allow the area to dry.