Ceramic, porcelain or stone tile add beauty and luxury to our home. Unfortunately, the downside to such eye-appealing floors is the risk of lippage which is the difference in height between the edges of the tiles. The result is a warped and ridged surface that isn’t completely flush, and may affect the aesthetic of your flooring, not to mention that it is a potential tripping hazard.
To avoid lippage, follow these precautionary installation procedures: Start with examining the subfloor to determine if the surface is uneven. You can do this by placing a leveler in the center of the room to determine if the floors slant. If there is a slant, or if the boards warp in the middle and pull away from the walls, you need to replace the plywood before laying your tile. Additionally, you need to replace the plywood before laying tile if there are large cracks in the concrete surface, water stains or ripples in the cement.
Remember this rule: For proper installation, larger tiles require a level tolerance of 1/4-inch per 10 feet. In other words, the subfloor’s level should not vary more then 1/4-inch per 10 feet.
The size of tile greatly contributes to lippage. Small tiles are easily aligned to adjacent tiles and will adjust to an unleveled grade. But, as the size of the tile increases, so does the challenge of creating a flush surface. Today 16-by-16 and 24-by-24 inch tiles are becoming more common. These less forgiving tiles in addition to the likelihood of an unleveled surface will increase the possibility of lippage occurring.
In addition to ensuring you’re working with an even subfloor, you need to make sure that your thinset adhesive or mastic is applied evenly. Use a trowel, and spread the mastic evenly in all directions.
Lastly, there are tile leveling tools that can help install large-format tiles in a more easily-achieved lippage-free manner. These excellent tools help keep the surfaces of tiles flush with one another during installation and also during the initial slump and shrinkage time that occurs with commonly used mortars.