Check that the existing tiles are firmly bonded, level, clean, and free of cracks or loose pieces
Repair or replace any damaged tiles before starting
Remove dirt, grease, wax, soap residue, and sealers from the surface
Roughen the tile surface with sanding or grinding to improve adhesion
Vacuum and wipe away all dust after surface preparation
Measure the area and plan the tile layout to avoid small edge cuts
Mark reference lines to keep the new tiles straight
Use a high-quality bonding primer if required by the adhesive manufacturer
Choose a tile adhesive suitable for tile-over-tile installation
Mix the adhesive according to the manufacturer’s instructions
Apply adhesive with the correct notched trowel
Press each new tile firmly into place with even spacing
Use tile spacers to maintain consistent grout joints
Check alignment frequently with a level or straightedge
Cut edge tiles as needed to fit around walls, corners, and fixtures
Allow the adhesive to cure fully before grouting
Remove spacers after the adhesive has set enough to hold the tiles
Apply grout into the joints and clean excess grout from the tile surface
Seal grout if required after it has cured
Reinstall trim, baseboards, or fixtures once everything is fully set