Proper subfloor thickness for porcelain tile?
I'm planning on laying down some porcelain tiles in my living room but concerned about the appropriate subfloor thickness.
Currently I have 5/8 plywood glued and screwed to 2x10's which are 16" on center. I have another tile floor that the new install is going to butt up against so I need to plan this properly so I have enough space to level the floor as I go and ensure I don't end up too high
The tile I have measures 11mm thick which is about 7/16". I'm also installing in floor heating which will be secured to the plywood and then completely submerged in self leveling concrete.
Does the self leveling concrete contribute to the floor strength? Meaning, do I still need to add 1/4 or 3/8" cement board (or similar) and then add the concrete or is just the concrete adequate? My gut says the concrete will add the stability required for a porcelain install but I want to be sure.