Repair cracking grout

Close-up of a person's hands applying new grout to a cleaned, empty grout line between ceramic tiles.
Photo: Nothing Ahead / Pexels
A hand holding a grout saw, carefully scraping out old, cracked grout from between tiles.
Photo: Vladimir Srajber / Pexels

Understanding Tile Lippage

Lippage refers to differences in the height between the edges of adjacent tile modules. This variation can affect the perceived evenness of a tiled surface.

The American National Standards Institute (ANSI) standard A108.02, Section 4.3.7, defines lippage and outlines acceptable variations in tile installations.

Factors Influencing Lippage Perception

Several factors can influence how lippage is perceived. These include the inherent thickness variation and allowable warpage of the tile modules themselves.

The spacing between tiles, the angle of light (natural or manufactured), and the reflectivity of the tile surface can also accentuate otherwise acceptable variances in tile height.

Substrate and Installation Impact on Lippage

Variations in the plane of the substrate, or the surface beneath the tiles, can significantly affect lippage. An uneven substrate can lead to an installed surface that does not meet lippage standards.

Specifically, when tile is installed using the thinset method over an uneven substrate, the resulting surface may exhibit unacceptable lippage.

Key takeaways

  • Lippage is the difference in height between adjacent tiles, defined by ANSI standards.
  • Tile warpage, thickness, spacing, lighting, and reflectivity all influence the perception of lippage.
  • Uneven substrates can cause lippage issues, particularly with thinset installations.

Related tools

Estimate materials with our free tile calculator on Tile Calculator.

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