We have a room that we are going to remodel the ceiling, walls and floor. The room has had water damage due to tidal surges over the years from being located in a coastal area. We need to know what is the most waterproof material we can you use on the ceiling, walls and floor in case it had any water to come in again. The floor has concrete. The approximate highest depth we have had in this room is maybe 2 feet. We will use this room for a spare bedroom with a bath. We were thinking maybe using porcelain tile on floor and maybe tongue and groove cypress on the walls. Also, we need to know what to use for the bath.