I recently demoed my bathroom and am getting ready to start putting it back together. It is a 90 year old house and built out of terra cotta bricks with an brick exterior (not a stick frame).
I am putting in a tub where one side will be against the exterior brick wall. The wall is not flat/even. Before I took out the tub, there were old subway tile that were cemented directly onto the terra cotta. The cement ranged from 1/2 to 1 1/2 inch thick depending on the imperfection in the tile. My question is how to mount new tile on the wall after I put the new tub in. My thought was to:
1. Install the tub first flush with the wall
2. Float thinset on the terra cotta blocks (no fasteners - can't really drive them into the terra cotta bricks - they shatter)
3. Set 1/2 hardibacker into the thinset to provide a flush level surface for the tile
4. Seal the hardibacker with Redgard
5. Apply subway tile with thinset.
In addition, by the time I'm done, thickness of materials on the blocks will be approx 1 1/2 - 2". Too much overhang for the edge of the tub? Should I back the tub an inch or two from the wall before I start adding the surface?
Any thoughts? I'm worried about just putting the tile straight on the terri cotta due to the uneveness of the the surface; I was hoping that the hardibacker would provide the nice smooth surface. I included a picture of the terra cotta blocks for reference.