What is lippage and how can you prevent it during tile installation?

• A. Lippage is the height difference between adjacent tile edges; prevent by ensuring flat substrate, correct trowel notch, consistent mortar coverage, and using a tile leveling system.
• B. Lippage is the grout color mismatch.
• C. Lippage is the tile thickness variation only due to packaging.
• D. Lippage is caused by using too large tiles.

Answer: (A)

Lippage is the edge height difference between adjacent tiles, so some edges sit higher or lower than their neighbors and the surface isn’t flush. This creates a stepped look, uneven grout lines, and can even cause trip hazards.

Prevent it by starting with a truly flat, level substrate. Use a straightedge to check for bumps or hollows and address them with leveling compound or patching as needed. Choose the proper trowel notch for the tile size and ensure full mortar coverage—back-buttering oversized tiles helps the tile bed evenly. When setting, press and twist the tile to seat it firmly into the mortar and use a tile leveling system to hold adjacent tiles flush while the adhesive cures. Maintain consistent joint widths and recheck the surface as you go, correcting any high spots before grout is applied.

Grout color mismatch, packaging-related thickness variation, or tile size alone do not cause lippage—the issue is the edge-to-edge height difference and how well the tiles are bedded and held flush during setting.