Q: I’m planning to install ceramic floor tiles in my bathroom. The tiles are glazed, so I wasn’t planning to use a sealer. However, my neighbor says that even if the tiles are glazed, I still should seal the grout joints. Is this correct?
A: Although sealing isn’t required for glazed tiles, since liquids can’t permeate the glaze, the grout on any floor should be sealed to provide the most water-proofing. For best results, mask the grout lines with painter’s tape and apply the sealer with a narrow brush. For such applications as mosaic tile, sealing the hundreds of tiny grout joints isn’t really practical, so be sure to apply a high-quality waterproof grout in lieu of a sealer.