The other is foam backer board which is ok to install over concrete.
Tile backer board on concrete floor.
Cement backer board is a thin layer of concrete designed to be setting surface upon which tile can be installed.
Installing a cement backerboard is crucial when you want a waterproof tile floor that lasts for years without cracking.
However a homeowner may need to raise the floor slightly before installing tile and lack the experience or time to install a mortar bed.
To achieve the ideal flat surface most contractors rely on the backer board.
Technically cement board can be laid over a concrete slab as the base for a tile installation.
This provides a solid surface under the tile that prevents flexing that could lead to cracking.
Check with wedi schluter laticrete goboard or whichever manufacturer to see how they want their product installed over a concrete subfloor.
Install a cement based backer board following the manufacturer s instructions.
But doing so is a very laborious time consuming process that is likely more trouble than it is worth.
Use a polymer modified thin set a type of mortar to attach the backer board to the subfloor.
If the subfloor doesn t have enough stability you can usually but not always remedy the situation by installing cement backer board also called cementboard.
When installing a ceramic tile floor on a concrete subfloor you don t have to worry about flexing as long as the concrete slab is at least 1 1 8 inch thick which most slabs are.
It s available in sheets of many sizes with 3 foot by 5 foot sheets being the most common.
A better solution is to prepare and resurface the concrete slab so that it can accept thin set adhesive or a mortar base onto which to lay tile.
Cement backerboard is a thin layer of concrete with fiberglass mesh on both sides.
Placing cement boards over the concrete subfloor is an excellent way to create a solid and smooth subfloor.
Cement board is used for most floor tile and has all but replaced plywood and drywall backer materials for wall tile applications in wet areas like showers and tub surrounds.