I cover some of the specifics of how to layout and set up a tub to install tile around it.
Transition from wall tile to bathtub lip.
This kohler acrylic tub is thick the flange is more than a 1 2 thick if you run the cement board over the flange and the tile which is about 1 2 thick when thinsetted it will come too far into the tub.
Then apply a generous amount of thin set to the bottom bathtub tile and position it 1 8 in.
This issue is sitting there for a long time now and really bother me.
Similar to the gap that can exist between your wall tile and tub you may have a space between the floor and your bathtub.
This video will show you how to set tile around a tub.
The best approach when installing cement board or other tile backer around a tub is to keep the cement board out of the lip area.
As with any other gap near your bathtub you ll want to close the opening to prevent any possible water damage or the onset of mold and mildew.
Apply it to the wall with the bottom edge about 1 4 in.
Above the lip of the tub.
I checked the tile grout.