Whether on your walls or the floor, tile is durable, attractive, and easy to clean and maintain. But installing it can be a challenge—as any amateur DIYer will quickly learn. The job seems straightforward, but it requires a lot of precision, and even minor imperfections can become major eyesores if they aren’t addressed appropriately.
One major potential headache: tile lippage. Lippage is what you get when adjacent tiles aren’t at the same level, with one tile slightly higher, creating a “lip” you can see—and feel (or trip over). Lippage can be caused by a variety of problems, including shoddy workmanship, warped tiles, or an uneven substrate. There are professional standards for acceptable lippage—generally, for tile with grout lines up to 1/4-inch wide, the tile can have lippage up to 1/32-inch, and tile with wider grout lines can have lippage up to 1/16-inch. (To give you an idea of what that looks like, a credit card is roughly 1/32-inch wide.)
So what can you do if the floor or wall tile is already installed and grouted and you can spot lippage—but ripping out the offending tiles and replacing them isn’t an option? You have exactly two options.
Measure first
Before you do anything, measure your lippage. As noted, some lippage is normal (and often unavoidable), but the lighting in the space can accentuate it and make it seem more drastic than it is. The easiest test is to slide a credit card along the floor or wall. If you hit a hard stop, you’ve got a lip of more than 1/32-inch (use two stacked credit cards for larger grout lines to look for 1/16-inch lippage).
If you have lippage that exceeds those standards, note each instance. If it’s the entire floor, you’re probably better off tearing it out. If it’s just a few spots, you might be able to fix the problem.
Option 1: Grind it
If the lippage isn’t too terrible and only affects a small number of tiles, you might be able to grind the edge down to make it even—or at least appear even—using a hand sander or an angle grinder (or, in a pinch, low-grit sandpaper).
You’ll have to be careful to choose the right sanding pad for the type of tile you’re dealing with, and you’ll want to be very conservative and careful. This won’t work if your lippage is significant, but for minor problems you might be able to carefully sand down an edge or three, then polish and seal the area.
Option 2: Grout it
If you’re not comfortable sanding down your tiles, you can also try solving the problem by creating a “ramp” of extra grout. This can be a tricky operation, as you don’t want the ramp to be obvious—and it’s important to keep in mind that this will only work with minor lippage. If you’ve got 1/8-inch of lippage, a grouted solution will be very obvious.
For minor lippage, however, you can start by filling in the grout line as normal, then load up your float again and grout against the lipped tile, filling the joint up to the top of the lip. During the wash, use your sponge to carefully shape the grout so it gradually rises from the edge of the lower tile to the edge of the higher tile. Take your time—once the grout sets you won’t be able to adjust it without sawing it out and trying again. If you get it right, the lippage will be visually concealed and you won’t stub your toe on it any longer, due to the gradual rise of the grout.