I am about to do a shower and I have the bathroom gutted out to studs
I am watching youtube vidoes by The TileCoach who shows how to float walls in order to have plumb and swquare surfaces for your tiles.
Why can't you set your backboards plumb and square using shimming or something else instead of floating walls when installing tiles?
Best Answer
You can shim backer board.
Depending on the tile size and how it meets with a seam I will mesh tape and float my seams to reduce cracking.
If a tile seam ends up close to a backer seam. This is where I float a wall not to try and square things up.
A vertical surface being filled with mortar to square it up just sounds nuts to me.