Tile around tub

I am remodeling my bathroom and have questions about tiling my tub. See picture. I have removed the existing tile down to the studs. Questions:

1. Do I need to install a vapor barrier over the studs?
2. I assume I use 1/2" cement board?
3. On the top stud, do I put the cement board right next to the tub?
4. When putting the cement board on the tub face, how do I handle the (22.5) degree angle? Do I have to cut two pieces of cement board and cut the side at (22.5) degrees?
5. I assume I should use matching colored caulk between the tub and tile and grout the rest?

Thank you for your help!

Mike

Anyone have any thoughts?

I would use alf inch "hardy backer". If you put 1 side on the small part of the face first you can put the longer peice on and just back cut it a little. Then put on the top. Caulk where the tile meets walls, floor, and tub. Grout the rest. I wouldnt use a vapor barrier, the backer board will do.

If you only back-cut one panel side, the angled cut will be longer than the panel that was only cross-cut. They should both be cut at (22.5) degrees.

If you can't do that for some reason then I would square-cut both pieces then tape and bed the angle with thinset filling the void. That will fill and properly peak the outside corner.

The backerboard is the least of your worries. When it comes time to do the tile you should use either metal edging or bullnose to make those (22.5) degree angles. This will take a little finessing in either case.

You don't need or want a vapor barrier on the studs but liquid waterproofing on top of the board would be dandy.

The board on the deck should be away from the tub rim 1/8" maybe and then caulked to allow for a little flexing when the tub is full of water and people. Same goes for the tile.

Thanks all!

Seems to be working!