Step 3 · Create Tile Access Opening
This is the most critical and delicate step. Measure the escutcheon plate of the NEW valve. Mark a cutting area on the tile that is slightly smaller than the new plate so it will cover the hole. If possible, align your cuts with existing grout lines. Put on your safety glasses, dust mask, and hearing protection. Use an angle grinder equipped with a diamond blade to slowly and carefully cut along your marked lines. Once the tile is cut, use a hammer and a small chisel to gently tap out the cut tile piece(s). Then, cut and remove the backer board behind the tile to fully expose the old valve and surrounding pipes.