17 Oaks
Silver Member
Is there any chance of putting in a powered vent? That would be your best choice. As far as paint goes, look at one of the epoxy based paints or go with a waterproof primer such as BEHR, Watertite or Rust-Oleum, then paint with a good quality semi or gloss over that. But my first choice would be to get a powered vent in the room.