How to Lay Cement Backer Board

Before learning how to lay cement backer board, first understand exactly what cement backer board is. Cement backer board, also sometimes called cement-fibre backer board, is a strong water-resistant base for stone, ceramic, and porcelain tile. It is so water resistant the backer board will not decay, expand, or deteriorate due to changes in temperature or humidity.

When to Use Cement Backer Board

Cement backer board is usually required for any tile installations in high moisture areas such as the bathroom or kitchen. To not have one in those areas could cause tile to fall, break, and bring on expensive, avoidable repairs. Now that you understand the facts of backer board, you can move forward to learn how to lay cement backer board in your bathtub.

Prepare the Area

Preparation of the work area is a non-negotiable step involved in how to lay cement backer board. First, tape a piece of plastic and slide a piece of plywood over the tub to protect its surface.

Next, remove any tub handles and spouts. If there is already tile on the wall, hammer or pry it all off. Cut out the drywall where the cement backer board will be placed. You are now almost ready to install the backer board.

Prevent Moisture

Like any other wet zones in the home or any place opened up to the outside elements, a vapour barrier must be created to protect the wall space between the studs and any adjoining walls. It's not enough to know how to lay cement backer board – you have to prevent moisture that seeps through the tile work and backer board from causing internal water damage to the rest of the house.

Roofing felt should be used as this vapour barrier. Cut the felt so that it fits into the areas and so that each piece overlaps by at least six inches on vertical joints and two inches on horizontal joints.

Use a silicone sealant between the roofing felt and the tub to keep water from seeping through the joints. Now the wall is ready for you to put up the cement backer board.

How to Lay Cement Backer Board

How to lay cement backer board from this point on is very similar to installing drywall. Pre-cut the backer board to the dimensions required to fit the areas abound the bathtub.

A jigsaw with a carbide blade works well because carbide blades have no teeth but instead have a rough extremely hard tungsten carbide coating that limits the amount of dust.

Follow the manufacturer’s instructions on how to lay cement backer board as some instructions for backer board may vary slightly. For most, using backer board screws would suffice.

Backer board screws are specially made with a corrosion-resistant coating and so that the head does not stick up through the backer board. The final step involves taping the joints with alkali-resistant tape and a thin set mortar. Allow all this to dry for at least a day before putting up the tile.

Learning how to lay cement backer board properly will prevent any costly water damage in the future and ensure a nice watertight seal from the rest of your home.