Hey everyone, this is my first post here so go easy on me. I am finishing a bathroom I've got the square framing for a door to a walk in shower I want to tile. I want to make an arch in the door way ceiling, then tile it. I've heard a couple different ways for the base and would like some advise. I've read that I can use 1/4" sheetrock doubled up and soaked wet, then secured in place in the arch and let dry. I've also been told I can do this same thing with 1/4" plywood. If either of these are right, which one is the best? If neither are right, what is the best way to tile an arch? I hope I've given enough info.