Draw a leveled line where the bottom of the second row will fall.
Tiling uneven walls shower.
Find a matching thick chair rail edging 12 piece and you ll be fine.
You could have wrapped around the edge w the tiles for a neater look.
I ended up going w a 1 thick basalt chair rail.
When your walls are uneven and you use very thick tile which yours is it s going to happen.
Whatever you put there you are going to see the uneven tiles.
This will provide a straight edge for the tile to follow and help support it while it dries.
You should have used the proper substrate for your shower walls.
Begin by removing the old tile or the fiberglass shower wall.
If any part of that should get wet you could have some issues.
Also tile is heavy so put down blankets to protect the floors and tub from being damaged by falling pieces.
This is a dusty job so use plastic to cover your doorways wear a respirator that s rated for dust cover the floor with a drop cloth and make sure there s plenty of ventilation.
You still may be able to do it by removing the last tiles and redoing it.
Just get some chair rail molding or some type of 1 trim pieces.
Attach a straight board to the backer board along the line.
If the shower base is uneven tiles will have to be cut to fit the last row.
Things you will need measuring tape tile wet saw leveling spacers and wedges trowel thinset mortar rubber mallet grout grout float grout sponge.