Tiling problems
Tile Lippage on a Screed Floor — Why It Happens
Every lippage complaint traces back to floor flatness. SR1 is the tile industry's answer.
Large-format porcelain (600×1200 and up) fails lippage at any flatness worse than SR1. That's ±2mm under a 2m straight edge — and sand-and-cement rarely gets there.
Liquid screed hits SR1 as standard. If your tiler is refusing to lay large format, a poured screed is usually the answer.
Flatness spec vs tile format
| Tile format | Minimum flatness |
|---|---|
| Under 300×300 | SR2 acceptable |
| 300×600 | SR2 borderline |
| 600×600 to 600×1200 | SR1 required |
| Above 1200mm long edge | SR1 with rectified edge; laser-flat |
If you already have lippage
- Below 3mm — grout and live with it
- 3–5mm — grind and re-tile that section
- Above 5mm — lift, latex-smooth or repour, re-tile
Frequently asked
Tile lippage on a new floor?
Send photos and the tile size. We'll tell you if it's fixable in place or needs a repour.