No, you can install GoShelf directly into the tiles using an angle grinder with a diamond blade for cutting tiles. Draw a level line and mark the walls ½” less than 7”, 8” or 9” starting from the inside corner. Use the grinder to plunge into the tile creating the 4 slots needed for the anchoring plates. Use safety gear and a shop vac to help catch the dust. Using an extra set of hands for the vac is recommended.