Lay down a vapour barrier overtop the concrete pad then fasten 3 4 inch plywood using a ramset to the concrete pad through the vapor barrier then install the heating system to the plywood followed by applying the self leveling mortar over top the heating system and plywood and finally installing the tiles over top that.
How to install ceramic tile over plywood subfloor.
Concrete board concrete board also called backer board comes in 1 4 and 1 2 thicknesses and is usually sold in 4 x 6 sheets.
Use intervening layers of two sheets of plywood.
When applying cement backer board over a plywood subfloor be sure to adhere the two surfaces together with thin set adhesive.
When it comes to mortar latex or epoxy options are best for installing tile over tile.
Check for dips in the floor by sliding a 4 foot to 6 foot straight edge in different directions all around the room.
And screw the cement backer board down with special screws that countersink into the backer board such as backer on screws available at the home depot.
It should be fastened to the subfloor using thinset and then screwed down every 10 square.
Use thinset with a higher latex content thinset is the wet base that you first trowel on the plywood to make the tile stick.
The plywood adds stiffness and stability to the floor.
Also consider that doors cabinets and other hardware might need to be reworked or replaced with new ones to compensate for the higher floor.
This is a mixture of cement fine grain sand and water that will adhere the new tile to the old.
Bc plywood over the old subfloor using construction adhesive and driving 1 1 4 in.
Add a layer of 1 2 in.
With the plywood in place install the backer board as you normally would.
There are two materials commonly used for laying ceramic on plywood or osb that are applied before the tile.
This will distributed the stress caused by movement of the subfloor and prevent cracking in your tile.
While tile can be laid on plywood do not install tile directly onto the plywood subfloor itself.
A successful tile installation project requires a level surface.
Screws every 6 in.
6 18 width across the joint.
Fill seams in the subfloor with caulk.
Use a thin set product to install ceramic tile over existing tiles.
You will use the flat trowel to apply a thin layer according to the manufacturers specifications.
When the tile installer enters the room and is ready to begin working the subfloor must be completely flat and clean and all mortar used to install the underlayment must be dry.