by Donato Pompo, CTC, CSI, CDT, MBA
Lippage is the vertical displacement between two adjacent tiles of a ceramic, glass, or stone installation. When excessive, this can lead to numerous problems, ranging from chipped edges to snagged furnishings and appliances to safety hazards.
There are industry standards for determining whether the amount of lippage is acceptable or excessive. American National Standards Institute (ANSI) A108.02-2013, General Requirements: Materials, Environmental, and Workmanship, Section 4.3.7 (“Lippage−Guidelines, Explanation, and Caution”) deals with what is allowable ceramic tile lippage and how to avoid excessive lippage. It states for grout joints that are less than 6 mm (1⁄4 in.) wide, the allowable lippage is 1 mm (1⁄32 in.), plus the inherent tile warpage. For grout joints 6 mm (1⁄4 in.) or wider, this becomes 2 mm (1⁄16 in.), plus the warpage. On the other hand, in the 7.2 edition of Marble Institute of America’s (MIA’s) Dimension Stone Design Manual (p. 14-3 “Horizontal Surfaces/General Notes,” Section 4.0−Lippage) simply says lippage should be limited to 1 mm (1⁄32 in.) for natural stone tile installations.
The challenge in trying to minimize tile lippage has to do with numerous compounding conditions, including the substrate’s flatness, which can have significant effect particularly when one is adhering directly to a concrete slab. Per ANSI A108.02-2013 Section 4.1.4.3.1 (“Horizontal Subfloor Surfaces”) and .2 (“Vertical Surfaces”), the substrate needs to be prepared before the tile installation such that the maximum allowable variation from the required plane for tiles with all edges shorter than 380 mm (15 in.) is no more than 6 mm in 3 m (1⁄4 in. in 10 ft), and no more than 1.6 mm in 0.3 m (1⁄16 in. in 1 ft).
For tiles with at least one edge 380 mm (15 in.) or longer, the maximum allowable variation from the required plane is not more than 3 mm in 3 m (1⁄8 in. in 10 ft), and no more than 1.6 mm in 0.6 m (1⁄16 in. in 2 ft). If the substrate is too irregular, then it is difficult for the installer to compensate for the irregular surfaces and install the tile in a manner to minimize lippage.
Medium-bed thin-set mortars
There is an erroneous belief among some tile-installers and specifiers who think using a medium-bed thin-set mortar adhesive—which can be applied as thick as 19 mm (3⁄4 in.)—is designed to compensate for substrates excessively out-of-plane. Industry standards for thin-set mortar adhesives, such as Section 2.1 of ANSI A118.4-2012, Standard Specifications for Modified Dry-set Cement Mortar, says dry-set mortars are designed as direct-bond adhesives. They are not intended to be used in truing or leveling underlying substrates or the work of others. (Due to this common misunderstanding, the industry is in the process of eliminating the name ‘medium-bed’ mortar, and changing it to ‘dry-set mortar for large and heavy tile.’)
Substrates need to be prepared before adhering tiles. High spots on concrete slabs must be ground down and low spots filled with special patching mortars or cementitious self-leveling mortars to achieve the appropriate flatness or slope. Medium-bed mortars are only meant to be used for large and heavy tiles so they do not sink into the thin-set mortar during the installation; they can also be used to compensate for ungauged tiles that vary in thickness from each other.
I’ve noticed that in some homes I’ve been in, that there is significant lips on the edge of tiles. I do think it is important that there is a slight lip, but nothing too big. Having one too big would be a home for dirt and other things to get caught in. Just be sure if you are doing something like this yourself, that you do it to the proper specifications.
Good take on what is acceptable and what isn’t with tile lips. I think a slight lip is great but it’s easy to go overboard. Thanks for sharing.
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What percentage of floor tiles that are at the 1/32″ limit for lippage, is acceptable? In 340 Sq. ft. we have 40 spots that are at 1/32″ lippage and 8 spots that are above. I have yet to see the percentage question addressed. Imagine a floor where all tiles are at 1/32 lippage. Would it technically be acceptable? With the above specs our floor looks terrible. we can”t even push our kitchen chairs under our table without having to lift them>
I have the same issue..exactly the same! I know this is an old post, but please share if you received a reply to your question. Thank you in advance.
My Question is similar to Mike B.’s. I have a 2000sqft house that is tiled throughout. Nearly each tile has at least one adjacent tile that is uneven (i.e., there is lippage throughout the house) and I would be hard pressed to find a tile with an no lippage. The RESIDENTIAL PERFORMANCE STANDARDS GUIDELINES states: “…Lippage greater than 1/16″ is considered excessive…except where…tile [is] larger than 13 × 13 inches.” My tiles are about 20″. For me, it is not that there is lippage, but the fact that there is lippage THROUGHOUT the house. What is the corrective measure for this?
I also have the similar problem. Any inputs in this matter are highly appropriated.
There is no percentage of tiles with lippage in excess of the ANSI standard stated. I guess the installers are expected to complete the job with no lippage beyond what is allowable. This is the same as other floor covering categories. Manufacturers have a realistic 5% error rate but installers, as the final quality control step, have no acceptable error rate. They could always follow the NAHB performance guidelines which are more forgiving for imperfect situations.The NAHB, as stated by Mark S. does not even list an acceptable lippage measurement for tiles larger than 13″. Maybe whatever lippage is present is acceptable to them? As stated in the article, there are usually several contributing causes for the final lippage.
There are tiles that are sunk in lower that the adjacent tile. What is the remedy to laying them even. We would like these tile removed and reinstall. Is it possible if tile is pulled it will make the floor weak and the other tiles may become loosen. So disappointed in the overall job. About 20% of the floor has lippage.
You are joking right when you fix a tile bigger than 600 mm long they don’t make them straight so you will always get lippage if you want no lips buy a vinyl floor
Buy he way 3 mm is the industry standard in the uk
I have an 80 square foot bathroom set with 12” by 24” porcelain tiles. The first tile job was ripped out because the lippage was severe among other problems. The second installation I still think is not right. When two tiles are next to each other i expect them to be smooth when I run my hand from one to the next. The contractor laid a credit card down on a tile edge where there was Lippage and once the card was pushed against the next tile the adjoining surfaces where smooth. I expect all the tiles to be laid like that. He said the credit card differential was acceptable with some tile industry standard but if it is not acceptable to a customer how can they make that excuse? I don’t know what to do or who to trust.
Tile is not perfect. Tile is not square. The same tiles in a box are not all the same size that is why there is an ANSI standard so the contractor can sue you for his money if it comes within the standards. You cant make a tile job perfect since tile is not made perfect. Just use common sense about the amount of lippage there is. Some home onwers are just cheap and dont want to pay and some tile setters are hacks. The card trick is a good way to check lippage for a commercial job. In residential, home onwers are more picky and expect more perfection so the contractor should bid accordingly, knowing how most home owners are with expectations. That is why I stopped doing residential.
If you expect/want no lipage plan to purchase an excessive amount of tile.
I’m having the same battle with KB Home. I paid for an upgraded rectified Emser tile with zero discernible warpage. They laid every single tile 7/32 to 9/32 averaging 1/4 grout line with zero tile warpage. One quarter of the 900 SF area has lippage that exceeds or surpasses 1/16. They are trying to kus replace the tiles in questions but when they replace them adjacent tiles become the problem.
There’s an arrow on the back of most floor tile. Point the arrow in the same direction as the others and there’ll be no 👎lippage.
I have a few areas of tile Lippage in a newly laid kitchen with large format 9×47 non-rectified tiles. There is one area in particular that although to the eye is not bothersome I can really feel under my feet. Am I better off leaving this alone..can it do more harm than good replacing a tile on an already grouted floor? I know it shouldn’t be acceptable, but should I just leave well enough alone if it looks good?
I should add that the Lippage is about a “quarter” high in the areas I speak of.
Fran. I have a similar issue. Did you ever get an answer? Or did you just leave it alone?
Isn’t there a term for intentional tile lippage as to give tiled surfaces a rustic effect
Do these lippage requirements apply to travertine or limestone around a pool outside?
I would hope so, since the tripping hazard is potentially fatal, however I understand that outdoor is a different set of conditions. Just wondering what is acceptable outside when the stones are first laid.