Lippage is when one tile edge sits slightly higher than the next. It's usually caused by an uneven floor or wall, uneven adhesive, or a slight natural bow in larger tiles. A small amount is normal and allowed for in British and European standards: porcelain tiles can be up to 0.5% out of flat (a maximum of 2mm) and still meet the standard.
To reduce lippage, make sure the surface is flat and use full adhesive coverage. If you're laying large-format tiles, wood-effect planks or any tiles in a staggered pattern, levelling clips are essential, as these are the most likely to show lippage. Long and large tiles should also overlap each other by no more than a third of their length, as brick bond, where each tile overlaps the next by half, makes lippage much more noticeable.
If you have any concerns about your tiles, please send us photos before you lay them and we'll take a look. We're unable to accept claims once tiles have been fixed.