Place the cement board.
Tiling around a bathtub lip.
You may wish to alter this height if possible to minimise tile cutting.
Fill the gap between the tile and the tub with caulk.
Mark a horizontal line around your bath at this height.
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.
Then apply a generous amount of thin set to the bottom bathtub tile and position it 1 8 in.
To tile around a tub or shower start by measuring the height of the back wall from the lip of the tub to the top of the area to be tiled.
Unless there is already a backer board installed you must place a cement board.
Check if you need to adjust this mark to avoid laying slivers of tile at the top and bottom.
Above the lip of the tub.
Apply it to the wall with the bottom edge about 1 4 in.
I am tiling a greenboard wall above a bathtub.
The tiling scheme will largely dictate where to start tiling and how the wall should be marked out for tiles start by measuring the height from the lip of your bath to the top of the planned tiled area.
This video will show you how to set tile around a tub.
I cover some of the specifics of how to layout and set up a tub to install tile around it.
Divide the dimension in half and make a mark there.
Use backboard screws to secure the cement board to the framing.
The cement board must be.