Step 3 · Cut Tile for Access
This is the most critical step. Measure the new valve body. Using a marker, draw a square or rectangular outline on the tile around the old valve. This opening must be large enough to work in and fit the new valve, but smaller than the remodel plate you purchased. To minimize tile chipping, apply painter's tape along your cut lines. Put on your safety glasses and dust mask. Use an angle grinder equipped with a diamond-tipped blade to carefully cut along the marked lines. Work slowly and let the tool do the work. Once cut, you may need to gently chisel out the cut piece of tile and backer board.