What is tile lippage, and how much is acceptable?
Lippage is the height difference between the edges of two neighbouring tiles. The North American installation standard (ANSI A108.02) allows about 1/32" for grout joints narrower than 1/4", and about 1/16" for wider joints, plus the small warpage the tile itself is allowed. Most lippage comes from an uneven substrate, thin or patchy thinset, or tile with a bow in it. A leveling system holds edges flush while the thinset cures, but it can't fix a floor that isn't flat.
How much lippage is allowed
| Grout joint | Allowed lippage (ANSI A108.02) |
|---|---|
| 1/16" to under 1/4" | About 1/32", plus the tile's allowed warpage |
| 1/4" and wider | About 1/16", plus the tile's allowed warpage |
These are the limits for a pass. Raking light from a window or a long hallway shows far less than this, so on large tile and planks most setters aim for dead flat.
What causes lippage
- A substrate with high and low spots. Large tile bridges dips and rocks on bumps.
- Thinset coverage gaps. Back-butter large tile and lift one now and then to check.
- Tile warpage. Long tile often has a slight bow, so keep running-bond offsets to a third or less.
- Joints too narrow for the tile. Pressed-edge tile needs a wider joint to hide size variation.
- Walking on the floor or pulling clips before the thinset has cured.
How to prevent it
- Check the floor. Use a long straightedge and fix high and low spots before you tile.
- Use the right joint. Follow the tile maker's minimum. See the clip size guide.
- Clip every edge. At least every 12 inches, closer on large or thin tile. The calculator counts them.
- Tighten evenly. Seat each wedge with a plier until the edges sit flush. If an edge stays high, add thinset rather than more wedge pressure.
- Let it cure. Leave clips in until the thinset can take foot traffic, usually overnight.
Frequently asked questions
What does lippage mean in tiling?
It's the height difference between the edges of two neighbouring tiles, where one edge sits proud of the other.
Can lippage be fixed after the tile is set?
Only by lifting and resetting the high tile, or by grinding, which can damage the glaze. It's far easier to prevent it while setting.
Do leveling clips eliminate lippage?
They hold neighbouring edges flush while the thinset cures, which removes most of it, but the floor still has to be flat first.
