Tile Leveling Systems and Lippage Control
Tile Leveling Systems and Lippage Control
Lippage is the difference in height between adjacent tiles. For LFT, lippage tolerance is typically 1/32 inch (0.8 mm) for grout joints less than 1/4 inch, and 1/16 inch for wider joints, per ANSI A108.02. Tile leveling systems (TLS) are used to minimize lippage. There are two main types: clip-and-wedge systems (plastic clips embedded in mortar and wedges that tighten tiles together) and screw-cap systems. These systems hold tiles at the same height while mortar cures. They are especially important for large format tile because the tile's size amplifies minor height differences. Traps: over-tightening wedges causing tile breakage or mortar squeeze-out; leaving clips in place too long (they must be removed after mortar sets but before it fully cures); and relying solely on TLS without proper mortar coverage. Worked example: When installing 24x24 tile with a 1/8-inch grout joint, use a TLS with clips placed at least every 12 inches along the edges. Tighten wedges until snug, but not so tight that mortar oozes out. After 24 hours, remove the clips by kicking them or using a mallet; then grout.