I'm trying to fix my bathroom, which desperately needs a lot of work. I have never done anything like this before so I have been reading a lot of things on the 'net. The tiles from mid wall down to the tub have buckled because of water damage so I took all of them out and the wall came off with them. I removed all of the damaged area and now I have a huge gaping hole revealing the woodwork behind. I have a fan drying the wood, so I want to start repairing as soon as everything is dry. One of the small boards is very water damaged, but I plan on adding a supporting board right underneath it. I have been researching a lot of things, and right now I'm confused if I should use green board or cement backer board for the wall. The water from the shower does hit the wall a bit so this wall will get a little wet each day. Also after I repair the wall, I need to replace the exhaust fan because it really doesn't do anything and mold has started growing on the ceiling. Ideally I want to keep the housing intact and just swap out the fan and motor, but this fan is probably older than I am. Is this possible? Thanks in advance.