code
Existing slab [flat] -resolve drainage issue with a sloped base/ power chisel, some hydraulic cement, and a thin set water proofing membrane system for finish tile to mount onto. Your wall substrate- if older house likely sheet rock on your walls. At best maybe some green board (moisture-resistant sheet rock). Most current codes will require a cement backer board for tile in wet areas, e.g., Durock. This would go over your wall waterproofing membrane. floor to slope to the drain? It’s like a typical drain in a custom shower base, however, in this instance it was notched into the existing floor joists and extra structural support was added. It is a bit tricky; hire a competent qualified contractor with experience doing these types of installations. Check local building codes, and if structural work needs to be done you will most likely need the help of an architect or structural engineer.
3. Compact shower stall. A mini shower stall with a partial wall is another good option, somewhere between a traditional shower and a wet bath. The openness makes the room feel larger, but the partial wall offers some sense of division.
Q