Here's the short version on a previous temp ensuite reno. Sister-in-law gets cancer, moves in with us while getting chemo, she takes over son's room and I reno our ensuite into a temp bedroom. Repaired subfloor that was rotting, took out old rotting aqua board behind shower stall and around soaker tub, put in concrete board around where shower stall is going to go back in and also on wall aound soaker tub (boxed soaker tub in and made a cool captains bed for my son). We painted the concrete board.
Here's the obvious question: Can we tile over top of the painted concrete board? Can I sand down the paint to rough it up so we can tile over it? Will it just not work or will it just fall apart after a few years? Is it impossible and do I have to rip it all out again and put in new concrete board?