How much lippage is acceptable?

The Tile Association's guidelines for tile fixing allow variation across joints of 1mm where joints are less than 6mm wide and 2mm where they are 6mm or more, with flatness within plus or minus 3mm under a 2m straightedge.

Why is lippage worse with large tiles?

Because long tiles are slightly bowed as manufactured, and the longer the edge the larger the step that bow produces at the joint. Narrow joints and offset brick-bond patterns both make it more visible, since there is less room to lose the difference.

Can proud tile edges be ground flat?

On some stone finishes, yes, as part of grinding and honing the whole floor. On glazed ceramic or polished porcelain it removes the surface permanently and leaves a dull patch, so tiles outside tolerance are lifted and relaid instead.

Would wider grout joints have prevented it?

They would have hidden more of it. Wider joints absorb the normal warpage of large tiles, which is why tile makers specify a minimum joint width for their formats. They do not correct a background that is out of flatness tolerance.

Low risk

Updated 30 August 2026

Uneven Tiles With Edges Standing Proud

Tile edges stand higher than their neighbours, so the surface catches the light, the mop and sometimes a bare toe.

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What's happening?

Lippage is the step between two adjacent tiles at their shared joint, and unlike most tiling complaints it has a published tolerance rather than an opinion. The Tile Association's guidelines for tile fixing allow a variation across joints of 1mm for joints less than 6mm wide and 2mm for joints 6mm or more, with finished flatness within plus or minus 3mm under a 2m straightedge. Two things make lippage worse than the tiles deserve. Large-format tiles are slightly curved out of the box, so the longer the edge, the bigger the step at the middle or the ends. And narrow joints leave nowhere to lose the difference, which is why a 2mm joint shows a step that a 5mm joint would have absorbed. Raking light then makes every step visible.

What usually causes it?

A background that was not flat enough before tiling, outside the plus or minus 3mm under a 2m straightedge tolerance
Large-format tiles with normal factory warpage, laid with joints too narrow to absorb it
Brick-bond or offset patterns with long tiles, which put the bow of one tile against the end of its neighbour
No levelling clips or tile levelling system used where the format really needed one
Adhesive bed too thin or inconsistent, so tiles could not be adjusted to a common plane
Tiles from mixed batches or different calibres laid together, so thickness varies tile to tile
Tiles moved or walked on before the adhesive had set, dropping some edges below others

Is it dangerous?

This is a quality-of-finish fault, not a safety one, and there is no structural consequence to a proud tile edge. Two practical consequences are worth naming. A proud edge on a floor is a wear point and a stub point — it chips, it catches a mop and it is what a bare toe finds — and HSE treats uneven floor surfaces as a contributor to slips and trips rather than a purely cosmetic matter. And lippage often travels with poor adhesive coverage, because tiles that were rocked into line on a thin bed tend to be the drummy ones, so a lippy floor is worth tapping while you are looking at it.

Can I fix it myself?

Measure it rather than argue about it, because a number changes the conversation. Lay a 2m straightedge across the floor in several directions and note the biggest gap under it, then use a steel rule or a feeler at the worst joints to record the actual step. Photograph it with a light held low and along the surface, since raking light is what makes lippage visible in the first place. Grinding proud edges is occasionally done on stone but it takes the finish off a glazed or polished porcelain tile permanently, so it is not a DIY fix. Filling the step with grout does not remove it.

When should you call a tiler?

Call the tiler back where measured steps exceed the tolerance in the Tile Association guidelines, where the floor is outside plus or minus 3mm under a 2m straightedge, or where proud edges are chipping. Bring the measurements and the raking-light photographs rather than a general complaint. Call before tiling too, where the background is uneven: correcting a wall or floor first is far cheaper than lifting new tiles off it, and it is the plasterer or screeder who owns that flatness.

What will the tiler actually do?

Measure flatness with a 2m straightedge and record the actual step at the worst joints against the published tolerance
Establish whether the cause is the background, the tile calibre and warpage, or the fixing method
Level the background first — dubbing out, a levelling compound or a screed correction — rather than absorbing it in adhesive
Set out the pattern and joint width to suit the tile format, widening joints where warpage needs the room
Fix with a full bed and a tile levelling system where the format requires it, checking with a straightedge as work proceeds
Lift and relay the areas outside tolerance rather than grinding a glazed or polished surface

Frequently asked questions

We’re happy to answer all your questions.

Sources & References

Tiles That Sound Hollow When TappedCaution Floor Tiles Cracking Across A RoomCaution Floor Tiles Slippery When WetHigh risk Wavy Or Uneven Plastered WallsLow risk

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