shower renovaton in motor home

Reather than tile I would use a swan stone product. My mind went blank on what it is called but Home Depot sold it. It is about a half inch thick and you can get it in sheets that you can cut to fit. It is then glued to the walls. I used some left over pieces in the kitchen area of our rig and it has held to the walls real well. You then caulk the edges and the joints. It isn't cheap but it will last forever and never leak like tile can.
Ron