You shouldn t add any backer board over the top of it.
Tile underlayment membrane vs backer board.
Two common types of underlayment are ditra a flexible plastic decoupling membrane explained later and cementitious backer units also known as cbus cement board or cement backer board.
It s waterproof which makes it ideal for wet.
This is the industry standard most preferred by construction pros when installing ceramic or porcelain tile backer board comes in four foot by eight foot and three foot by five.
The facing serves as an integrated waterproofing membrane so you don t need to install a separate layer of plastic behind the tile backer or a sheet membrane over the backer.
Secondly once the self leveler is dry you can adhere tile directly to it.
Ardex liquid backer board is an example of a self leveler that doesn t need reinforcement.
Concrete backer board durock and wonderboard which is the standard material for tile underlayment.
In many ways however an uncoupling membrane such as schluter ditra is an even better backing material for reasons other than the fact that it doesn t raise the height of the floor as much as cementboard.
Uncoupling membrane cementboard has replaced a manually applied mortar bed to emerge as the standard underlayment for a tile floor.
Custom s fiber reinforced levelquick is another.
Georgia pacific s densshield is one such product.
Just reading the definitions alone doesn t provide too much of a difference as both uncoupling mats and backer board are used to prep the subfloor to help prevent loss of bond.
Membrane faced board only.
The question is which will be a more effective sidekick in your fight to keep your floor tile victorious.
One type of tile backer board is made with a water resistant facing on both sides of the board.