How to Install Backer Board

Backer boards are installed underneath or behind ceramic tile and natural stone installations in your home.

Backer board comes in various sizes and is similar in construction to drywall. With the proper tools and information, installing backer board for your next tile or natural stone project will be a breeze.

Measure the space to determine how much backer board is necessary. Multiply this number by five percent to account for mistakes and unusable pieces.

Install a vapor barrier of either polyethylene or asphalt-backed paper to prevent moisture damage between the wall or sub-floor and the backer board.

Clean the installation area to make it free of dust, dirt and debris. Use a vacuum to make sure everything is completely removed.

Cut pieces of the backer board to fit the space. This can be done in different ways. Use a hand-tool with a carbide tip and score along your measured marks, applying pressure until the cut breaks clean. Use a diamond or carbide blade when cutting backer board with jigsaws or circular saws.

Fasten the backer board to the wall or sub-floor. Use corrosion-resistant screws or nails to attach the backer board to the wall studs or sub-floor.

Seal the joints. Use an alkali-resistant tape, followed by a layer of thin-set mortar.

Things You Will Need

  • Carbide-tipped hand tool
  • Corrosion-resistant screws
  • Alkali-resistant tape
  • Thin-set mortar
  • Vacuum


  • Always measure twice. Doing so will result in less loss of material because of incorrect measurements.
  • Allow the thin-set mortar to dry for at least 24 hours before beginning tile installation.
  • Mark your stud locations along the floor or the ceiling to make installation of backer board much easier.


  • Make sure the surface on which you will be installing the backer board is level. If the area is uneven, the final installation will be ruined.
  • Use a silicone sealant if you are installing backer board in wet areas such as around sinks or bathtubs.