Specifying and MasterFormat
How can architects help avoid excessive tile lippage (or perceptions thereof) on their projects? It is the same old answer: write a project-specific, detailed MasterFormat specification that is complete, concise, correct, and clear. In the specification, it is not only important to specify the appropriate reference standards in Part 1–General and the correct products with performance requirements in Part 2–Products, but it is also critical to specify the key steps of the installation in Part 3–Execution.
It does not matter who is at fault when there is a problem—everyone ends up paying, either in time to defend themselves, money to fix the issue, or with their reputation. Therefore, it is in everyone’s best interest to ensure installation specifications are thorough and clear, as well
as unambiguous. The following paragraphs summarize the key content that should be in specifications for tile and stone installations to avoid excessive tile lippage.
Part 1–General Requirements
1. The key industry standards must be called out:
- ANSI A108 for surface preparation and the installation of stone, glass, and ceramic tile;
- TCNA Handbook for Ceramic, Glass, and Stone Tile Installation for specifying specific installation methods;
- Marble Institute of America (MIA) Dimension Stone Design Manual for adhered and mechanical anchored applications;
- ASTM C1242, Standard Guide for Selection, Design, and Installation of Dimension Stone Attachment Systems, and ASTM Stone Physical Property Standards for the respective geological classification of the stone being used;
- ANSI A137.1, American National Standard Specification for Ceramic Tile; and
- ANSI A138.2, American National Standard Specification for Glass Tile.
2. A specific quality assurance (QA) section needs to be prepared to verify performance of a material and that it will be suitable for the intended application.
3. A required mockup should become the standard upon approval for installation methods and for workmanship for aesthetic quality. It should include the specified lighting to which the tile will be subjected. The mockup can become part of the work upon approval.
4. Single-source responsibility from an installation product manufacturer should be required, and include a minimum 10-year labor and material manufacturer warranty. The quality of the products required for the extended warranty tends to be much higher; it also ensures compatibility between the materials. It is also important to require a letter in writing from the manufacturer, before installation, stating its products are suitable for the intended application.
5. Tile-installers—both setters and helpers—should be certified or verified to demonstrate they know and are current with industry thin-set standards (e.g. Certified Ceramic Tile Installers [CTI] through the Ceramic Tile Education Foundation [CTEF] and Tile Installer Thin-set Standards [ITS] verification through the University of Ceramic Tile and Stone [UofCTS]).
Part 2–Products
1. The specifications should be performance-based. Reference specifications only call out products meeting the minimum requirements, which are essentially the least-expensive products with the lowest acceptable level of performance.
2. Stone should meet ASTM minimum/maximum physical property requirements for their respective geological classification. Ceramic tile should meet ANSI A137.1 standards, and glass tile should meet ANSI A137.2, Specification for Glass Tile. If narrower grout joints are desired, one should specify rectified tiles to meet the respective ANSI A137.1 tolerances.
3. In order to avoid excessive concentrated tile warpage, one should require one-tenth the length of the measured span of the tile to not represent more than 25 percent of its total allowable warpage.
4. Installation products should be provided by a single-source manufacturer who offers a minimum 10-year labor and material warranty. Thin-set adhesives should meet or exceed ANSI A118.15 for higher performance. Further, an appropriate cementitious, urethane, or epoxy grout—part of the labor and material warranty—should be called out.
5. A cementitious self-leveling mortar or patching mortar, as supplied by the single-source manufacturer of tile installation products, should be called out for adjusting the substrate before tile installation.
6. An appropriate movement joint sealant and backup strip—per ASTM C920, Standard Specification for Elastomeric Joint Sealants—should be listed as being supplied by the single-source manufacturer of tile installation products.
Part 3–Execution
1. The specific installation method and detail from TCNA Handbook for Ceramic, Glass, and Stone Tile Installation must be specified. Direct-bond applications normally require adjustments to the substrate to make it flat enough. Mortar-bed applications should be able to correct irregular substrates.
2. In Division 03 00 00–Concrete, it must be noted substrates are to meet ANSI A108.01 tolerances and surface textures in preparation for tilework. Normally, the tile installer will still have to make additional surface preparations.
3. In Division 26 50 00–Lighting, it should be noted fixtures must be placed in a manner to avoid direct lighting on tile wall surfaces.
4. Installers must be required to inspect substrate conditions before commencing with the installation. When there are any obvious defects or conditions preventing a satisfactory tile installation, the installer is to notify (per ANSI A108.02) the architect, general contractor, or other designated authority in writing; he or she is not to proceed until satisfactory conditions are provided.
5. The tile contractor should be required to provide an allowance for preparing direct bond substrates to meet ANSI A108.02-2013 Section 4.0 (“General Requirements”), which will allow them to achieve a proper, flat tile installation without excessive tile lippage. This may require grinding high spots on concrete surfaces or applying a self-leveling or patching mortar to make the surface reasonably flat within the specified plane. It normally requires scarifying concrete surfaces to open up pores and removing contaminates.
6. Tile and installation products must be installed per manufacturers’ instructions and industry standards. Products should be mixed per manufacturers’ instructions. Temperature limitations must not be exceeded, and shading or heat must be given as required. Further, work must be protected from both weather and other trades.
7. Tile installed in a staggered pattern must be offset no more than 1⁄3 if any edge of the tile is greater than 457 mm (18 in.).
8. The width of the grout joint should be specified per ANSI A108.02-2013 Section 4.3.8, with maximum allowable lippage stated per Section 4.3.7.
9. Movement joint placements should be specified per TCNA EJ171 within the field of tile, at their perimeters, and at transitions in plane or to other materials. The architect must provide movement joint design and layout instructions for the tile-installer.
10. The architect needs to provide a detailed quality control (QC) plan, to be implemented by a third party. This to verify the:
- tile substrate is properly prepared;
- tile meets the specification requirements;
- specified installation method and procedures are being correctly followed;
- tile installation products are being correctly stored and used; and
- tile installer workmanship is kept consistent with the approved mockup.
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.