I am planning on redoing my bathroom in the upcoming months. I am going to be ripping out the old walls and tile floors and had a few questions.

First, I'm assuming I need to use a vapor barrier behind the drywall/concrete board correct? Does this go on all 4 walls as well as the ceiling? (bathroom is on the top floor of the house). Also, should I use green board or will regular drywall be OK to use?

Second, for the flooring, I was planning on ripping out the old floor down to the subfloor, checking to make sure the floor's level, etc, installing cement board and then tiling over the cement board, I just wanted to make sure that was the correct approach. Also, would it be easier to do the floors before the walls or vice versa? Thanks for your help.

We need to know what your sub floor is made of, dimensional lumber or ply. Vapor barrier on all outside surfaces including ceiling. Greenboard is water resistant , not water proof. OK to use in bathroom but not in wet areas around tub and in shower stall. We could use some more details about what you are planning.

I'm assuming the subfloor is made of plywood as it is in the rest of the house.

In the shower, I wanted to install tiles on cement board extending 5 feet up from the top of the tub (about 7 feet total from the floor), and drywall the rest of the way up to the ceiling. I am planning on only tiling inside the shower and having painted walls in the rest of the room.

When you get down to the sub you'll know what it is. If its dimensional you need a glued and screwed ply before your cement board. Stay with greenboard insiide the stall above the cement board, rest of the room is up to you but I usually go greenboard throughout