Blocking the Walls of Ceramic Tile Showers
To support the wall of ceramic tile showers takes extra bracing. That's partly because of the liner membrane that is run up the wall. It's also partly because the shower pan mortar slopes up the wall also. So you build a strong wooden box that defines the dimensions of the shower pan around the bottom of the shower.
All that's needed is blocks placed between wall studs to form a wall around the base of the shower floor.
Simply cut wood pieces to fit between each stud. You may use 1 or 2 inch lumber. A 2 x 10 piece is often the choice. You can nail through the wall studs into the blocks and then toenail also.
Remember this...
Mount the 2 x 10 blocks flush with the notches cut to provide clearance for the liner membrane. So the blocks should be set back at the same depth as the notches are cut.
Don't forget that the studs must be notched back 1/8 inch along the walls and 1/4 inch in the corners for the liner to fit properly.
See the next page about preparing the ceramic tile shower subfloor for a shower pan installation.