Lippage

Lippage is a term used in tile installation to describe a condition where tile edges are not flush with adjacent tiles, resulting in a visible lip or stepped edge along the surface. In floors, this can create a noticeable uneven line and may present a tripping hazard or make cleaning more difficult. On walls or vertical surfaces, lippage is often less dramatic but can still affect appearance and the effectiveness of waterproofing at joints.

Causes of lippage include a substrate that is not flat or has high spots, tiles of different thicknesses or warping, and improper mortar application or insufficient coverage. Other contributing factors are inadequate back-buttering, poor layout planning, use of a tile leveling system that is not appropriate for the tile, and cutting or handling errors during installation. Large-format tiles or natural stone are particularly prone when tolerances are not carefully managed.

Detection typically involves a careful visual inspection and the use of a straightedge or level to check for deviations across several tiles. Lippage may be more noticeable at grout lines or along the length of a run, and it can become more apparent once grout is applied.

Prevention centers on ensuring substrate flatness within manufacturer and industry tolerances, using tiles of uniform thickness, applying mortar evenly with back-buttering if recommended, and employing tile leveling systems to lock tiles in place during set. Proper layout, accurate cuts, and consistent spacing also help.

Remediation usually requires removing and resetting affected tiles to achieve flush alignment with surrounding tiles, often with improved substrate preparation and leveling to prevent recurrence. Minor lip issues are best avoided through careful preparation and adherence to installation best practices.