How do I stop tiles sticking up? Lipping and how to avoid it

Lipping, or lippage, are the words used to describe the height difference of tiles once they're installed. As you can imagine, tiles sticking up or proud means your tiles aren't sitting flush and this can negatively impact the look of your finished tiling project. Not to mention this can actually damage your tiles and cause tripping hazards if left unchecked on tiled floors.

But don't worry; we've got you covered with some explanations for why it happens and some tips for how to stop your tiles from sitting proud. 

What makes tiles stick out and cause lippage?

The main reason is the tile manufacturing process.  During production, most tiles will become slightly bowed from the heating and cooling stages; these cause the edges of the tiles to bend slightly. 

Unfortunately, this is an unavoidable part of making tiles no matter the measures taken during manufacture. But all is not lost, as you can minimise its effect by how you tile, which we will go into later.  

Tile Top Tip: Lippage is less obvious on smaller, square tiles than it is on larger rectangular tiles and plank tiles. 

European standards for tile bowing

The centre curvature allowance for porcelain B1 is +/- 0.5% of the diagonal size and for porous tiles (ceramic, stone, slate, etc.) B111 it is +0.5%/-0.3% of the diagonal size.

This means that on a large format 900x300mm tile, bowing could add up to 4.74mm and still conform to European standards. For example, if this tile was laid in a broken bond pattern that would mean lippage of nearly 5mm, which would look very obvious.

However, there is some good news: one way you can combat lipping is by using a bigger joint gap between tiles. The snag with some larger format tiles is how they are designed to have a rectified edge (a square profiled ground edge) and a narrow joint, meaning the height difference is more noticeable.

How to avoid lipping

• If you're tiling a floor, make sure the sub-floor (the surface you're tiling on) is level before tiling – you can use a self-levelling compound to even things out.
• Pre-lay on a flat surface and work out the pattern you will be using before you fix your tiles to the wall or floor.
• Use the right joint width; we recommend 3mm spacers for floor tiles but depending on the style, the gap can be bigger or smaller. Just be mindful that narrow gaps will highlight any difference between the tiles.
• When installing big tiles or long planks, use a tile levelling system to help create an even and level surface.

The Genesis GLS Spin Levelling System in action, showing how easily it creates a flush finish.

• Check your lights; extra bright or mis-placed lights can spotlight even the smallest inconsistencies.
• Manufacturers of plank tiles recommend no more than a 25% overlay. If it looks like there's too much lippage, laying the tiles out in a 1/4 or 1/3 broken bond pattern or a square bond could help minimise the difference.
• Please note, using a 1/2 broken bond with rectangular or plank tiles is usually a big lippage no-no and can even cause a trip hazard if used on floors.