Backer board and drywall seam

[Zatar]

Backer board and drywall seam make a very high spot. Unfortunately we have already taped and green waterproofed the seams.
Should we cut out the drywall and add hardi board to the ceiling or redo the whole three walls over again?

[Kman]

Welcome to the forum, Z.

I assume you're referring to the horizontal seam about five feet up from the tub, is that correct?

Two problems you've got there. First, you used Hardibacker, which is a little thinner than 1/2" sheetrock. Second, the sheetrock at that point is usually thicker because where is terminates at the top of the fiberglass tub/shower, (that's what you had there, right?) the sheetrock is taped and mudded, typically.

Those two things are the reason I always just take out the wall board to the ceiling. So that's what I would recommend you do at this point. Cut it at that joint and use Hardibacker to the ceiling.

You don't have to waterproof it if it's above the level of the shower head, just tape and mud the seams.

[tilelayer]

Hi Z


Kevin is spot on with his advice.

Sometimes we leave the top piece because it is already taped into the ceiling, if you decide to remove that top section of tile you're going to have to tape the new cement board into the ceiling to prevent any types of cracking from occurring.

[Zatar]

Dry wall replaced with Hardiboard and seams tapes. We have used Megalyte on the seams and everything is much more level after we smoothed out all the leveling material from our first attempt.
We will continued even though this has been a huge project to undertake.
We have a 1976 rambler, so anything can look better than the old fiberglass insert.
We are using 12x24 porcelain tiles and have a horizontal layout planned and will overlay the tiles around the niches. Overlaying appears the easiest rather than doing a trim or framing them out.
Our niches have been criticized over and over, but please just respond to technical advice and not shame us for trying a home project.
Questions??
We will waterproof the seams from the showerhead down.
Is it a good idea to use the waterproofing on the entire wall?
It does raise the wall up slightly, but not enough to cause a problem more than 1 or 2/16ths

[Zatar]

Ya.We are having multiple problems with our remodel with lights too.

Has not been fun.

[rmckee84]

Did you install a moisture barrier behind the CBU? If not then go ahead and waterproof the whole thing.