2nd image shows the room. The first image is where I have my questions. It's just the red circled area enlarged.
OK, if I get it down to bare studs, contractor mentioned it is a good idea to shim the studs a hair so tha backer board has a tny gap behind it.
Doing that, the backer board has a slight gap behind it right at the tub flange where it's nailed to the studs. He said fill that gap with silicone before putting the backer board against it.
He also said to leave a 1/8" gap below the backer board........ so the backer board doesn't rest directly on the tub.
He said do the same with the tile, then caulk or grout caulk along the lower edge of the tile.
Not done yet.
I found a tile guy to come look at it tomorrow.
He said he's put 15 lb felt on the studs, the backer board............. and I swear he said 1/4"
dat sounds way thin to this carpet dude.
Now, the real questions. Is any of what I described correct?
If not, what's the correct way to seal the wall cavity and build out the wall with backer board?
And is there any "wrong" type of backer board for tub walls?