Overreliance on spacers leads to consumer complaints

Does lack of willingness to purchase installation excellence exclude tile setters who craft quality work?

Coverings is not only an opportunity to see firsthand the latest tile and stone styles and trends; it’s an opportunity to learn about the latest technical and installation challenges and the efforts underway to address them. One such discussion at this year’s show last month was the premise that an increasing number of installers are not using measurements and chalk lines to square up and lay out their tile installations. Instead, they are relying on hard spacers, usually made of plastic, to determine the grout joint width and tile positioning, which can result in misaligned tiles.

Contrasting grout and tile make misalignment more obvious than less-contrasting grout and tile.

Contrasting grout and tile make misalignment more obvious than less-contrasting grout and tile.

NTCA requested this topic be included on the agenda for the ANSI ASC A108 Committee meeting held at the show. The discussion was initiated by NTCA Board member and Technical Committee Chairperson James Woelfel, who is active in development of installer and contractor best practices through involvement in and leadership of numerous technical committees. Reliance on spacers has become a critical issue, according to Woelfel, who, in addition to contracting, is engaged in inspection and consulting. He says this problem is the cause of about 80% of the inspections he has performed so far in 2019.

The committee discussed the well-understood and accepted function of the grout joint as the necessary adjustable component of every tile installation that accommodates variations in tile sizing, an inherent characteristic of tile. But hard spacers inhibit that adjustability factor. Accordingly, the less consistently-sized a tile is, the greater the misalignment that will be caused by hard spacers because of the greater need to adjust the grout joint for the tile size differences. 

ANSI A137.1

Rectified tile has less size variation, stipulated by ANSI A137.1, compared to calibrated tile, for which more size variation is allowed.

Conversely, the problem that Woelfel believes is on the rise would be less pronounced with rectified tile. This is because of the very small amount of size variation allowed for rectified tile, per ANSI A137.1, as compared to tile classified as calibrated tile, which is allowed more variation. 

Tile classified as “natural” has very intentional size variation for aesthetic purposes and is allowed the greatest amount, and many tiles have even greater intentional variation and fall outside the tile standard completely. 

But spacers themselves aren’t the enemy. They can be combined, or adjustable varieties can be used, to produce a good end result even when there is significant size variation in the tile. 

Exploring the cause of the issue 

The root cause of the issue is debatable. Perhaps there is a lack of awareness of size variation and how to deal with it, and a lack of qualified installers despite the availability of information and instruction available, especially online. Or, perhaps installers know better, but are working at rates that unquestionably require speed over precision. Is there a lack of willingness by homeowners and GCs to “purchase” installation excellence that excludes those who would take the time and make the effort to make aesthetic adjustments?

Spacers used in combination to give tile with purposeful size variation a consistent overall appearance.

Spacers used in combination to give tile with purposeful size variation a consistent overall appearance.

One can only speculate. Most inspection reports address only whether an installation does or does not meet industry standards. When it does not, the common presumption is that installer error is wholly to blame. But a deeper-diving, less black-and-white assessment might reveal significant culpability of homeowners and GCs choosing not to hire qualified labor. 

It’s an important question for the industry. Perhaps Woelfel’s spacer-related observations are a microcosm. Does an increase in improper spacer use signal worsening undervaluation of craftworkers and trade work? We should try to find out. 

Some installers use compressible materials like rope to space tile.

Some installers use compressible materials like rope to space tile.

If misaligned tile due to spacer use reflects a shrinking willingness to purchase trade excellence, could we trace the lack of qualified labor back to that lack of demand? Could it be considered a labor market correction, i.e., a generalized lowering of output quality that equalizes the supply side with the demand side? 

It may sound controversial but does the opposing theory make sense? Is it possible that the tile-consuming public not only wants  – but is generally willing to purchase excellence – yet contractors and installers are either disinclined or unable to find a way to meet that demand despite the profitability of doing so? If that were true, contractors that do deliver quality work would have an almost unmanageable backlog of work, while subpar contractors would get very little work and be virtually driven out. Unfortunately, it seems the opposite is the case: quality contractors often struggle to get work, and report that the projects they bid on are routinely awarded to contractors that do not provide the same level of installation quality.

Determining precise layouts

Whatever the reason for it, the implications aren’t limited to some misaligned tiles. Even if all the tiles on a job were miraculously the exact same size, with zero adjustability needed, Woelfel’s observations still signal a problem.

The method of using measurements and chalk lines to lay out an installation is the skill that enables the tile installation to be oriented in the best way possible for a given tile and pattern in a given space. Laying out tile is the process of determining the size and placement of cuts (partial tiles) before any tile is set. Especially for larger installations, it’s a decision-making process, which may even involve a home or building owner since the “best layout” is often subjective.

One homeowner might want full tile at a certain threshold or transition to other flooring, regardless of how that arrangement decision impacts the tiles on the opposite side of the room; while another individual would prefer a more centered design. 

Tiling the main aisles of a furniture showroom requires precise layout to ensure tile rows are aligned on center with columns.

Tiling the main aisles of a furniture showroom requires precise layout to ensure tile rows are aligned on center with columns.

Only through professional layout processes can the layout options, including the aesthetic pros and cons of each option, be known and evaluated and an informed decision be made. Similarly, the professional layout process enables installers to adjust a layout to meet specific points and locations as needed in-situ. Installers may have to ever-so-slightly expand or compress a layout in order to “make it work,” imperceptibly, and over the course of multiple rows.

Several ANSI Committee members said they support Woelfel’s thinking that language could be added to ANSI standards and/or the TCNA Handbook relating to the potential for spacers to result in misaligned tiles. As part of the related awareness efforts, the larger implications should be emphasized. The idea is to not only avoid crooked tiles due to spacers, but to ensure that the highest level of craftsmanship is available wherever and whenever needed. This is not accomplished by seeking out qualified installers and companies only for the most critical projects, but rather by helping to sustain them by being their regular partner on the jobs in between. 

Why do manufacturers require a 33% offset brick pattern?


Greetings! I was wondering if you could solve a mystery for me. On numerous jobs, for both walls and floors, we are asked by interior designers to install 12 x 24 or similar tiles in a standard brick aka 50% offset pattern. However, for many of these, printed on the box of tile or stated on the order sheet by the distributor, it clearly states in one way or another, “Brick joint pattern to be offset 33%.” When we point this out, the designer doesn’t care and won’t approve a mockup (because they don’t want to order any extra tile). Most of the time the 50% offset on the floor doesn’t end up becoming a lippage or shadowing problem, though we also use a leveling system so perhaps that helps mitigate it. On walls, however, especially depending on the lighting, it can be a real problem.

I would like to know why manufacturers recommend this if it often isn’t followed (I see plenty of tile jobs installed with the 50% offset)? And why do most of the distributors display the tile on a display board with 50% offset if the manufacturer requests a 33% offset? Is everyone just trying to cover their butts on potential lippage and/or shadowing issues? And since tile setters are “the experts,” not designers or customers, is a mockup the only true way to relieve yourself of culpability if shadowing and lippage do result from disregarding a manufacturer’s recommendations?


Thanks for getting in touch and thanks for asking an excellent question.

At Coverings ’19, NTCA Training Director Mark Heinlein presented a demo about wall wash lighting and lippage, citing information from the ANSI standard, as two teams installed wall tile.

It is my guess that the designers you are working with may not be familiar with the requirements of tile industry standards and the reason why those standards exist and why manufacturers require certain offsets for tiles they produce.

Listed below are the tile industry installation standards that relate to this discussion:

  • ANSI A108.02 section 4.3.7 – Lippage – Guidelines, Explanation, and Caution
  • ANSI A108.02 section 4.3.8 – Grout Joint Size
  • ANSI A108.02 section – Running Bond / Brick Joint Patterns
  • ANSI A108.02 section Running Bond / Brick Joint and Any Offset Pattern (for your convenience, I have quoted this section here): 

As you can see, ANSI A108.02 is very clear. When this requirement is followed along with installing tile that meets the manufacturing standards of ANSI A137.1 and when the substrate flatness standard for tiles with at least one edge 15” or longer is applied, the correct mortar is selected and mixed properly, the correct trowel is selected and used properly by an adequately trained and skilled installer, a successful finished installation should occur. (Note: the substrate flatness requirement for a 12” x 24” tile only allows a maximum permissible variation of 1/8” in 10’ from plane with no more than 1/16” variation in 24” when measured from the high points in the surface.)

Lippage can become a real problem when the lights are turned on.

Allow me to state this another way:

  • Using tile that meets the requirements of ANSI A137.1 for Nominal Size, Caliber Range, Warpage and Wedging
  • Installing that tile on a substrate that meets the ANSI A108 requirements for flatness
  • Following the ANSI A108.02 and/or the tile manufacturer’s requirements for maximum offset
  • Following the details of the appropriate method selected from the TCNA Handbook for Ceramic, Glass, and Stone Tile Installation
  • Selecting the correct mortar or adhesive for the type of tile being installed and application it is to be installed in
  • Mixing the mortar or adhesive per its manufacturer’s instructions
  • Selecting the correct trowel and using it correctly to achieve the bond coat coverage rates required for the system equals a successful, long-lasting installation that will please the owner and end user.

Note that ANSI A108.02 states “…specifier and owner must approve the mockup and lippage.” In my opinion, the expense of purchasing an adequate percentage of tile to install the required offsets can be very minimal when weighed against the potential for lippage and lighting-related failures that can occur when manufacturer instructions and tile industry standards are not followed.

Industry standards and manufacturer recommendations of 33% or less offset for tiles with one or more sides 15” or greater are required because of the manufacturing process for tile. When ceramic tile is heated and cooled in the kiln, warpage can occur. This is a normal result of the manufacturing process. Many tile factories are excellent at controlling warpage, but it cannot be completely removed. That is why there are limits for how much warpage a tile can have detailed in ANSI A137.1 for tiles that are manufactured to meet that standard. Whether or not a given tile meets the warpage limit of ANSI 137.1 can be found in the information printed on the carton or on the manufacturer’s technical data sheet, or by contacting the manufacturer.

The NTCA Reference Manual contains valuable information about wall lighting and lippage control devices.

You are absolutely correct in noting that lippage resulting from a layout or offset pattern or other factors can become a real problem when the lights are turned on. This is especially true for walls when the lighting grazes the face of the wall or when there is a sharp angle of incidence from natural light on a floor. I have listed references on the following page for more information on this topic.

You are also correct in noting that lippage tuning devices can help mitigate these issues. The job of these devices is NOT to take the place of any of the standard requirements I described above, but they can be a useful tool to help installers remove the last bit of human error (typically a maximum allowed 1/32”) and to hold the tiles in place while the bond coat cures. I have listed references below for more information about these devices.

I do not know why manufacturers or distributors might show tiles in an offset pattern that is different than what is required for a specific tile or by industry standards. It could be oversight or lack of knowledge by the person designing or creating the mockups.

You are correct that it very often falls to the tile installation contractor and installer to be the industry expert that understands everything I have described above. The installing contractor and the installer are the last line of quality control before the installation goes in. When or if there is a problem after installation, it is the installer and installation contractor that gets the call. The installation contractor needs to have an excellent working knowledge of the industry standards, methods and best practices to be able to adequately communicate the potential issues during the bidding process and BEFORE the installation takes place. To avoid issues, contractors and installers should empower themselves with this knowledge and know how to identify problems and to stop and identify a resolution before proceeding with the installation. Other trades and professionals such as general contractors, architects, specifiers and designers will respect a knowledgeable tile contractor that is able to clearly communicate what must be accomplished and why. Mockups are a key element of this process and are strongly recommended.

I described the key elements of the ANSI standards that pertain to this discussion of your questions. In addition, there are several other key areas you can use to inform yourself and communicate to other about this subject. They include:

  • 2018/2019 NTCA Reference Manual section on Critical Lighting Effects on Tile Installations on pages 125 – 132.
  • 2018/2019 NTCA Reference Manual section on Lippage Control Devices and Edge and Lippage Mechanical Tuning Devices on page 172.
  • 2018 TCNA Handbook section on Substrate Requirements.  See the section on Substrate Tolerances and Large Tile on page 31.
  • 2018 TCNA Handbook section on Lighting and Tile Installations on page 34.
  • 2018 TCNA Handbook section on Flatness and Lippage on page 36.
  • 2018 TCNA Handbook section on Grout Joint Size, Layouts, and Patterns on pages 37-38.
  • 2018 TCNA Handbook section on Finished Tilework on page 39 (especially the section on “Visual Inspection of Tilework”)

I encourage you to read and become familiar with all of the standards, methods and best practices I’ve described above in your NTCA Reference Manual, TCNA Handbook and ANSI standards. This will help you be even more confident in describing why installation standards and manufacturer instructions must be followed. Any deviation outside of following them often becomes risk accepted by the installation contractor because at the beginning, middle and end of every job, the tile contractor is the industry expert.

As you and I know, tile isn’t simple or easy. Sometimes, for very good reasons, we can’t always give the owner or specifier what they think they want. Contractors such as yourself that have access to the NTCA member benefits of technical support and education can better communicate the need to apply recognized industry standards, methods and best practices for successful installations. As you know, membership in the National Tile Contractors Association is a major source for help in understanding the standards and how to apply them and avoid issues BEFORE they happen.

We encourage designers, architects, GCs, and specifiers to attend our many workshops and other education programs, or to become an NTCA member themselves. Please feel free to direct them to our website and calendar of events at www.tile-assn.com and click on the Free Educational Workshops link under Education & Certification on the home page. You are doing a great job in asking the right questions. I hope this helps. 

New protection for Illinois contractors – the buck stops at contractual privity

Privity of contract: A concept in law providing that only parties to a contract can enforce their rights or claims against one another. 

In late 2018 the landmark Sienna Court Condominium Association v. Champion Aluminum Corporation case overturned three decades of Illinois precedent that had allowed owners a narrow exception to assert claims against contractors and suppliers with whom the owner did not have a direct contractual relationship. The Illinois Supreme Court’s decision in Sienna, while only applying Illinois law, is important for owners, contractors and suppliers nationwide to review and understand as it addresses the bigger question of when or whether an owner can sue a contractor with whom the owner has no privity for defects claims (or other types of claims). In answering that question, Sienna provides much-needed guidance and protections to contractors who are not in privity with an owner.

In 2018, recovery for defects in the construction of a new residential property against a contractor who was not in contractual privity with an Illinois owner was through the doctrine of implied warranty of habitability (“IWH”). The IWH is a warranty implied by the courts as a matter of public policy that essentially promises (or warrants) that a home will be suitable as a residence. Prior to Sienna, owners of homes with construction defects had a narrow right (under limited circumstances) to sue the contractor who built the home under the IWH where contractor did not have a direct contract with the owner. Now under Sienna, however, the purchaser of a newly constructed home cannot assert a claim for breach of the IWH against a contractor when that contractor had no direct contractual relationship with the purchaser even if the builder-developer is insolvent and the homeowner has no other recourse. 

Sienna brings much-needed clarity for owners, general contractors and subcontractors who previously had to face potentially conflicting approaches to IWH claims. In Sienna, the Court emphasized that the warranty was an implied contractual term and therefore reasoned that absent contractual privity the IWH could not be applied to the subcontractors. To put the Sienna decision briefly in context, although the doctrine of implied warranty of habitability was first recognized by the Illinois Supreme Court in 1979, Illinois still did not allow homeowners to pursue a claim for breach of an implied warranty of habitability against a contractor with whom it had not contracted. But subsequently in 1983 the Illinois Appellate Court for the First District in Minton v. The Richards Group of Chicago held that the IWH could be asserted against contractors (including downstream lower tier contractors) by homeowners who sustained a loss “due to the faulty and latent defect in their new home caused by the subcontractor” and when the builder-vendor was insolvent. Minton became the precedent followed in Illinois for three decades until it was overruled by Sienna in late 2018. 

The Moorman Doctrine reaffirmed 

In overruling Minton, the Sienna court also reaffirmed the economic loss rule, which is in effect in many states, including Illinois. The economic loss rule provides that claims for classic breach of contract cases must be asserted only between parties to that contract (and thus an owner cannot directly sue a subcontractor for IWH claims when the owner did not directly engage the subcontractor). The economic loss doctrine makes it very difficult for homeowners to successfully bring claims for economic losses for repairing defective work against contractors and suppliers who were not in privity with the owner. 

Exploring “vicarious” liability for lower-tier contractors

In light of Sienna, subcontractors are now largely protected from direct claims by owners, but what about general contractors who find themselves liable to the homeowner by contract? No doubt the general contractor will almost always seek a defense, indemnification or contribution from their lower-tier and downstream contractors who were responsible for the claimed defects pursuant to their subcontracts. If their contractual risk transfer and indemnification agreements require the lower-tier contractor to indemnify and hold harmless the upper-tier general contractor now facing legal liability and exposure, it would be logical to expect that IWH liability would be passed on to the lower-tier contractor (absent specific contractual language to the contrary). The upper-tier contractor may also be protected as an additional insured under the lower-tier contractor’s insurance policy for the actions or non-actions of the lower-tier contractor. But even under such risk-transfer scenarios, which may include a contractual responsibility to make whole an upper-tier contractor that sustains a loss or incurs a financial liability, it would seem logical to expect that if the upper-tier contractor cannot be held liable in the first place under the IWH as spelled out in Sienna (meaning that the general contractor did not contract directly with owner), that there can be no claim for the homeowner to pass through for recovery from the lower-tier contractor. 

However, there are also scenarios that potentially may create exceptions to the protections under Sienna such as when an express warranty is given by the subcontractor and is then assigned to the buyer. But it will remain to be seen whether the subcontractor and by extension the indemnifying lower tier contractor can avoid IWH liability in such a scenario. 

Even though Sienna would appear to protect lower-tier and downstream contractors from IWH liability when, like the subcontractors, they have no contractual privity with the purchaser, the absence of case law providing Sienna-like protections specifically to lower-tier contractors means that lower-tier contractors would be well-advised to carefully construct and negotiate the terms of their indemnification and hold harmless agreements and limit the scope of their liability to higher-tier contractors. Likewise, lower-tier contractors may want to review how they craft and enter into contracts conferring additional insured protection to higher-tier contractors with a view towards limiting potential coverage liability. 

Post-Sienna, unanswered questions remain as to scenarios that may still open the door to IWH liability for downstream contractors. Sienna, for example, did not address whether its ruling could extend to other implied construction warranties, such as the implied warranty of workmanship. Sienna does, however, reiterate for owners, contractors and subcontractors the importance of a carefully drafted construction contract that explicitly addresses warranties (or waivers thereof) and properly allocates risk to the parties that can best protect against potential economic loss.

Perception vs. reality – the truth behind PBM flooring claims


ORLANDO, Fla. — At the Tile Council of North America’s (TCNA) Coverings press conference, held here last week, TCNA executive director Eric Astrachan shared information about current research into flooring made from plastic-based material (PBM). This included luxury vinyl tile (LVT), wood polymer composition (WMPC) flooring, stone polymer composite (SPC) flooring, clay polymer composite (CPC) flooring, and rigid core board (RCB) – the common denominator being plastic composition.

The study compared some of the popular beliefs about PBM flooring with the reality, as revealed in lab testing done in Clemson, S.C. The top beliefs of consumers about PBM flooring, derived from preliminary results from independent market research, include:

  • Belief of scratch resistance
  • Belief of wet area usage
  • Belief of durability, in general
  • Assumption of competitive pricing
  • Assumption of health and safety
  • Assumption of comparability to ceramic tile

As testing revealed, the perception and reality differ. Though many PBM floors claim to be “worry-proof,” “scratch-proof”, “life-proof” and “pet-proof” among other claims, virtually all warranties exclude scratching, indentation and pet damages, including, in some warranties, “loss of gloss/scratching,” “…damage caused by vacuum cleaner beater bar, indentation or damaged caused by spiked heeled shoes, improper rolling loads, caster wheels, chairs or other furniture without proper floor protectors and cuts from sharp objects,” and “scratches, indentation or reduction in gloss level is not considered wear.” In addition, manufacturers recommend the use of furniture pads, which are not depicted in advertising.

A predominant belief about PBM floors is that they are waterproof, and in fact are often advertised as such and encouraged for use in bathrooms, wet areas, and to combat spills and leaks. The study found, however, that warranties routinely exclude all water damage resulting from water passing through and around floor covering to the subfloor and other structural elements of the building.  The testing showed that, according to two international standardized tests for waterproofing, all the samples tested leaked through the seams to the subfloor below. What is ACTUALLY being warranted is that the plastic floor itself is unaffected by water. It does not take into consideration leaking through seams and damage to subfloors.

In addition, the study found that  90% of PBM floors tested supported the growth of mold, due to water leakage through seams into the subfloor, and the organic materials in the plastic provided nourishment for mold spores to grow. Mold spores in the seams can also be pushed into the breathable space which can contribute to respiratory and allergic effects.

PBM flooring is also believed to be slip resistant, though there is no standard for slip resistance testing in LVT flooring used by the resilient industry on wet surfaces. Using the ANSI standard A326.3 with a reference value of .42 DCOF, 16 samples – 82% — measured below .42 DCOF in all or some directions. Finally, the study tested hardness of plastic flooring relative to ceramic tile and other substances. PBM flooring rated #3 on the Mohs scale, just above talc and gypsum and equivalent to calcite, which is scrapeable with a copper coin. Ceramic tile, on the other hand, rates #7-#8, equivalent to quartz – which scratches window glass – and topaz, which scratches quartz.

Testing results shine a light on the differences between actual performance, advertised claims, and warranty exclusions by the PBM flooring industry.  For more information, contact TCNA at 864-646-8453.




The top ten requirements for a quality tile installation

In this article, the Ceramic Tile Education Foundation (CTEF) Blog Team updated an earlier piece about what makes a quality tile installation. These pointers are instructional to a wide audience, including A&D professionals, reinforcing the importance of working with skilled, qualified tile installers and writing other important details into the spec like movement accommodation joints and flat and level surfaces to ensure not just a beautiful installation, but a long-term, well-performing one. Read on, and visit www.ceramictilefoundation.org/blog for more informational articles, as well as related links for this story. – Ed.

What does it take to ensure that you have a quality tile installation? Based on our experience, knowledge and work with the Tile Council of North America (TCNA) Handbook, we have identified 10 requirements. Note that these aren’t all industry requirements. However, they all contribute to a quality tile installation. Here they are:

1. Hire only skilled tile installers

Only well-trained and experienced tile installers can produce installations of the highest quality that provide long-lasting beauty and functionality. Realize that tile isn’t just a decorative layer in a home or commercial building. It must meet specific standards so that it performs as it should over time.

In order to differentiate this quality oriented tile installer from others in the field, consider hiring a CTEF Certified Tile Installer (CTI). CTIs have proven that they have the knowledge and skills that meet industry standards and best practices.

2. Incorporate movement accommodation joints in the tile installation

All tile installations, both residential and commercial, will move with temperature and humidity variations.

To accommodate this expansion and contraction activity, the use of expansion joints per the TCNA Handbook for Ceramic, Glass and Stone Tile Installation method EJ171 is essential and required in all tile work. As stated in the Handbook, “The design professional or engineer shall show the specific locations and details of movement joints on project drawings.”

Be certain that all parties involved in the project including the architect, the specifier, the designer, the salesperson and the tile installer know and understand the critical use and placement of expansion joints.

3. Work only with premium materials to install tile

The use of premium quality bonding materials is money well spent.

Merriam-Webster defines premium as: “of exceptional quality or amount; also, higher priced.” 

Exceptional quality comes at a price. The components that are added to these materials provide enhanced characteristics that affect both function and durability. For instance, saving a couple of pennies per square foot on a conventional and less-expensive thin-set mortar rather than using a feature-laden, large-and-heavy-tile mortar is a foolish idea.

Tile industry experts agree this is one of the easiest insurance policies for preventing installation problems. All types of setting materials are available in various performance levels to meet the requirements of the job.

Contact the setting material manufacturer for products with the specific characteristics and performance levels necessary for success. Always pay attention to manufacturer instructions.

Additionally, always read and follow the manufacturer’s guidelines printed on the bag of any product since the mixing requirements and/or application may be different than materials used in the past.

4. Confirm that tile installation surfaces are flat

In order to provide a flat ceramic or stone tile installation, carpenters, masons, concrete finishers and other trades must meet the tile industry standards for flatness tolerances.

If substandard surfaces are encountered, they must be corrected before installation begins. Otherwise, you will not have a quality tile installation: the quality of the installation will be compromised.

5. Verify that the tile installation surface is rigid

Ceramic tile installations require a stiff or rigid surface. In some cases, installations, including natural stone, may require additional subflooring, wall studs or bracing. Realize that the substrate for natural stone tile installations must be twice as rigid as that for a ceramic or porcelain tile installation.

Tile contractors should always follow the applicable recommendations of the TCNA Handbook for Ceramic, Glass and Stone Tile Installation, the ANSI (American National Specifications for the Installation of Ceramic Tile) as well as the recommendations of the manufacturer’s products being used in the project.

6. Minimum mortar coverage must be provided

Tile industry standards require minimum mortar coverage of 80% in dry areas and 95% in wet (showers) or exterior areas. Natural stone tile installations require 95% coverage in all applications.

This refers to the contact area of the bonding material (thin-bed mortars, large-and-heavy-tile mortars or epoxy adhesives) with both the back of the tile and the surface being tiled.

7. Ensure that tile site conditions are controlled

Jobsite conditions can have a serious impact on the success or failure of a tile installation.

ANSI A108.02 section 4.1 (excerpted) states, “Installation work shall not proceed until satisfactory conditions are provided.”

Many products used in tile installations require that the temperature be maintained within a specific range and duration. Be certain to follow the manufacturer’s guidelines to ensure a long-lasting installation.

In addition, insist on a mockup so you can view a sample of the actual installation, which includes items such as tile color/variation, grout joint size/color and gauge the variation from tile to tile. The mockup ensures that the final installation meets your expectations.

8. Use only the correct tile installation methods and materials

Not all installation methods and/or materials are suitable for all applications. Be certain that your contractor will use the TCNA Handbook method rated for the intended application or a method that is recommended, fully specified, and warranted by the product manufacturer.

Research manufacturers’ websites to determine suitability, application recommendations and product warranty information.

Review the manufacturers’ product data sheets and recommendations for the tile, backer board, bonding materials, membranes and grout that will be used on the job.

Just because a product is available doesn’t mean that it is appropriate for a given installation.

9. Allow for adequate cure time

Allow a tile installation to cure sufficiently per the manufacturer’s recommendations before exposing it to moisture, traffic, temperature changes or overlaying products. Otherwise it will not perform as a quality tile

The amount of time required will vary based on site conditions and the specific materials being used.

10. Make use of crack-isolation membranes as needed

Cracks in concrete and other areas of movement should be treated with a crack-isolation membrane (ANSI A118.12) to help eliminate cracked tiles. As mentioned previously, the addition of a crack-isolation membrane can be cheap insurance that provides a beautiful and long-lasting installation.

Check with the membrane manufacturer for specific use and application recommendations.

Tiling pools?

The pool deck and walls in the spa area were installed with mosaic tiles, and larger tiles in the treatment rooms.

CTIOA field report provides guidelines and best practices to complement industry standards

Industry standards cover the basics of common tile applications, like pools, but contractors who take them on will tell you there’s a lot more to know. That’s not a criticism; it’s just the reality of what can reasonably be expected. An addition or revision to the TCNA Handbook or the ANSI standards often takes several years of behind-the-scenes research, information sharing, and collaboration before it’s proposed. Once it is, the consensus process sometimes dilutes the language or intent, or limits the scope of a proposal. 

TCNA Handbook method P602 is for installation of a mortar bed and tile in a concrete, shotcrete, or CMU pool tank waterproofed with cementitious waterproofing, the performance of which can be enhanced by application of a penetrating colloidal silicate beforehand.

Think about asking your extended family to agree on where to go on vacation together this summer and it’s easy to understand the challenge of getting 50 voters from various segments of the tile industry on the same page. While approved language is solid because of the rigor of the process, there’s often a larger body of information – a mix of facts, opinions, experiences, and preferences – that could also inform contractors’ decisions and processes. 

For pools, spas, and similar submerged installations, a plethora of additional such information was compiled by a Ceramic Tile Institute of America (CTIOA) pool-focused technical group, to provide non-proprietary options and best practices when the substrate is cast-in-place concrete, gunite, Shotcrete, or cinder block. The 17-page report includes sections on evaluating the structure/shell, maintenance, pool water chemistry, and more. 

Especially interesting and relevant to tile contractors is the section on the tile/coping interface, which is categorized in the report under five general design options on pages 2-5, printed here verbatim:

  1. Cantilevered concrete decking,
    image courtesy of CTIOA.

    Cantilevered concrete decking:
    A concrete deck around the pool spanning over the bond beam and waterline tile in a manner allowing the deck to “slip” back and forth as needed. This is usually accomplished with a trowelable membrane, #15 felt paper, 6mil. plastic or equal. A movement joint is then placed between the coping and the top of the pool tile.

  2. Cast in place concrete coping: Concrete coping formed on top of a bond beam, extending over the edge of a pool by 2” to 3” and generally terminates in line with the back of the bond beam. Any concrete sub-base or decking that butts up to the coping and/or pool shell must have an expansion provision between the two.
  3. Pre-Cast Coping, image courtesy of CTIOA.

    Pre-Cast Coping: This coping is generally cast into molds off-site using concrete or pressed clay, allowed to cure and then brought to the site for installation. It’s made in straight pieces, end caps, and varying radiuses that will accommodate different pool shapes.

  4. Quarried Stone Coping: Stone of various species, sizes, shapes and thickness installed onto the top of the bond beam.
  5. Mechanically Fastened Coping: Commonly used in Rim Flow and Slot drain pools, this type of coping is generally attached by fasteners to structural systems spanning over a trough designed for water to flow into. The coping is flush with the decking and the top of the tile, allowing a slot of 1/4” to 1/2” in width for water flow.

    Mechanically Fastened Coping, image courtesy of CTIOA.

The report notes that “the interface of coping and tile as they relate to the bond beam of pools and adjoining decking behind them can account for a significant percentage of pool tile failures when installed improperly… often a result of pressure applied to the pool shell, coping, and /or tile, from pool decking, and adjoining structures.” To avoid tile/coping interface related problems, the report provides “key points to keep in mind when installing coping:” 

To avoid putting pressure on waterline tile, cantilevered decking “must be free to slide over the top of pool bond beams” or “must be raised and bonded mechanically or chemically to the existing bond beam, bringing it up to the same plane as the top of the waterline tile.”

Movement joints should be installed between the tile and the coping.

Place cast-in-place coping “over a bond beam that is on the same plane as the top of the waterline tile,” bond it to the bond beam (unless intended as floating/unbonded), terminate the coping (its back side) where the pool structure terminates, and provide movement accommodation between the back side and any abutting material or structure, such as decking.

Ensure a “positive bond” between pre-cast coping (including quarried stone) and the bond beam, which can be accomplished by a thin-set or mud-set method, both of which are described in the report. 

In addition to the pool/coping interface information, contractors will also find useful details to consider on surface preparation, mortar bed scratch coating and floating, tile installation, and necessary cure time. While much of the report relates to design, decisions, and work that falls outside a tile contractor’s typical scope of work and responsibility, it’s information that can shed light on potential causes of tile issues, should they occur, for example faulty pool start up or maintenance practices that can adversely affect a correctly done tile installation. The combined “how to” and troubleshooting make the CTIOA report on tiling pools an essential reference for contractors that work on pools, in addition to ANSI standards and TCNA Handbook methods. 

The report is available via the site at CTIOA.org.

How will you stand out in a crowd of tile installers?

When I was 17, I started working with tile. Almost daily, when our crew would walk into the local sandwich shop or taqueria, we would get asked, “What do you do for work?” When we replied “We install tile,” nine times out of 10 the person behind the counter would reply one of two things: “I’m a tile installer too!” or “My neighbor/brother/uncle/son/daughter is a tile installer!” We would always get a chuckle and look at each other and say, “Yep, everyone is a tile installer!”

Seventeen years later, things haven’t changed much, and every third person seems to claim that they’re God’s gift to tile; it doesn’t seem to matter that they are currently hanging drywall or pouring overpriced lattes to hipsters.

So how will you stand out among this massive crowd of “tile installers”?

See, you and I understand that you’re different. For one thing, you’re reading the April issue of TileLetter. You also know what the TCNA Handbook is and have EJ171 memorized. You dream about tile and spend your free time hanging out online discussing best practices and sharing photos of your favorite work. But unfortunately Mr. and Mrs. Jones don’t necessarily understand the difference between you – the professional who has devoted your life to tile – and the weekend “contractor.”

Market what sets you apart from the crowd

So on top of memorizing the TCNA Handbook and spending all your free time thinking and discussing tile, you also need to be focusing on your marketing and selling skills. In fact, it’s your duty as the professional to educate your potential customers and your community on the proper ways to install tile that can last a lifetime and add major value to their home.

Unfortunately, you can’t just claim to be the best and expect results. You also don’t typically get to show off your knowledge of codes and “geek out” on an unsuspecting homeowner.

So what helps people see the difference? What motivates people to choose the right contractor for the job?

In this modern world, people have less and less time. Instead of researching books and instruction manuals, they are researching photos and videos of tile on their smart phones.

The good news is we all have the capability to produce the type of content they are looking for. 

These days it’s very easy for consumers to collect all the pretty photos of tile work they love, and they do this during the weeks and months prior to picking up the phone and calling a contractor. When it’s finally time to call someone, who do you think they’re going to call first? 

That’s right, the contractor that they already like, know and trust from that social media app. 

I want to encourage all of you to embrace the latest social media trends and find out where your ideal customers are hanging out online. There are many social and photo sharing apps but for now let’s just focus on Instagram (IG).

Focus on Instagram

I’ve gotten dozens of jobs from my presence on IG. I’ve done this by being consistent, showing my personality, creating a buzz by introducing new ideas and products to my followers – and above all interacting.

Just yesterday I was out to dinner with my family and a group of strangers came up to me and said they loved my tile work on IG! 

What are other examples of great IG content?

Carl Leonard of Cutting Edge Tile in Florence, N.J., and his business partner Dani Ganix have been creating Hollywood-quality promotional videos for their YouTube and IG pages. These are the type of videos a potential customer would watch and find entertaining and educational. @cuttingedgetile

Jason McDaniel of Stoneman Construction, LLC in the Portland, Ore., area, has been using his IG account to showcase his scribes, letting potential customers know that if they want a custom design, they need to call the Stoneman! @stoneman1273

I could go on and on and wish I had the space to mention all the amazing tile work I see on IG daily. If you’re new to IG or social media and don’t know where to start, feel free to reach out to me, I’m happy to help in any way I can. 

Luke Miller recently hired Designer Drains to create this one-of-a-kind drain cover to resemble an iconic landmark in his city; this has created a small buzz on his Instagram account. (Original art of Morro Bay, Calif., by Forever Stoked)

Looking for documentation for flooded houses with tile floors


We are working with flooded storm victims from Hurricanes Harvey and Irma. The issue we are facing is that these homes were inundated with 3-8 feet of water for 2-7 days…category 3 water, which includes sewage and other toxins. The insurance companies and the National Flood Insurance Program refuse to consider this flooring damaged and are not paying for it.

Our research has shown us that, after a period of time after the storm, these tiles become loose due to water finding its way under the tile and causing damage to the adhesives. In addition, this also allows contamination to the flooring system. It was also noted that some ceramic tiles are porous, and the tiles themselves could be damaged or contaminated.

Based on the conditions above, we are looking for some documentation or recommendations stating the following about the tile floors in this situation (average age of tile install 5-10 years):

1. That the tile floor is recommended to be replaced due to the reduction or loss of adhesion, and/ or

2. That the tile flooring itself, including the adhesive, may be contaminated and should be replaced.

We find it hard to believe that an average-aged home with tile floors would be completely sealed and have no water intrusion into the tile flooring system. I would love to discuss this with your team after you have discussed this issue. Thank you very much and we appreciate anything you could do to help us and the recent flooding victims.


There are a number of standards and best practices that guide tile installations in America. Installation and material standards and specifications are found in American National Standards Institute (ANSI) A108; A118; A136; A137.1; A137.2; A137.3. Installation best practices, methods and guidance are found in the Tile Council of North America (TCNA) Handbook for Ceramic, Glass, and Stone Tile Installation. In addition, manufacturer instructions for the application and installation of their setting materials and related products used in tile installations must be followed for every

Installation standards, methods and materials will vary depending on the particulars of any given installation. Is it for example:

  • A floor, wall or ceiling.
  • A wet area such as a shower or a steam room.
  • A residential or commercial installation.
  • Is the supporting structure wood or concrete or steel.
  • Is the tile ceramic/porcelain; stone or glass.
  • And many other considerations.

Because there are applicable standards, methods, best practices, procedures, materials and numerous details that apply differently to each of these installation types, one generic analysis cannot possibly apply to each. Installations that have been flooded and constructed to the requirements of tile industry standards, methods and best practices can withstand significant amounts of moisture better than other products. In flooded situations, forensic investigations may need to be conducted to determine the next steps.

For this reason, NTCA strongly encourages you to contact a NTCA Recognized Consultant to review your cases. Find a recognized consultant by going to the NTCA website at www.tile-assn.com and searching for recognized consultants under “Find a Member.” As an association of tile contractors and professionals, NTCA itself does not provide these consulting services.

Mark Heinlein, NTCA Training Director

Fire and Sound Rating for Wall Assemblies


I am a design consultant, working on existing nearly 100-year-old structures. We need to be in compliance with current code for fire separations one- and two-hour.

Due to the historical aspects of some of the structures we cannot do much to the exterior but can enhance fire safety when doing alterations that affect the interior walls and floors.

Since the Space Shuttle uses ceramic tiles on the outside of the hull to preserve the lives of the crew from the inferno re-entry heat, why can’t ceramic tile be a part of the fire-rated floor and possibly ceiling assembly?

The intrinsic value added is we may be able to make the assembly thickness narrower, thus keeping the first floor and existing ceiling at the 7’-6” minimum clear building code height. Net results could be no fire sprinklers required, in certain situations, greater fire safety, lower cost for the upgrade and possible new avenues for upgrading older existing structures using something with thousands of years of historical reliability that goes through several thousand degrees of heat, to get produced.


I can direct you to the 2018 edition of the Tile Council of North America Handbook for Ceramic, Glass and Stone Tile Installation.

In the TCNA Handbook you will find method RW800-18 and associated descriptions and details for Fire and Sound Ratings for Wall Assemblies. This method begins on page 293 and includes a variety of details and information on materials and layers to design and construct fire rated tile assemblies.

Copies of the TCNA Handbook are available for purchase through the NTCA store at www.tile-assn.com. I hope this helps! 

Mark Heinlein, NTCA Training Director

NIOSH Silica Webinar Planned for May 14

Oberlin, OH, March 27, 2019—The National Institute for Occupational Safety and Health (NIOSH) will be hosting a free silica safety webinar on Tuesday, May 14 at 11am PST. Designed for stone countertop fabrication employers, the webinar will describe the dangers of silica exposure, outline employer requirements to comply with OSHA’s Respirable Crystalline Silica Rule, and offer methods employers can use to protect workers.

During the webinar, representatives from OSHA, NIOSH, and the California Department of Public Health will provide information related to silica exposure, including health risks, methods to protect employees from silica dust, and OSHA requirements. Two Natural Stone Institute Accredited members, Jonathan Mitnick (CCS Stone) and David Scott (Slabworks of Montana) will provide practical tips on controlling worker exposure to silica dust and share the steps they took to ensure their shops were OSHA compliant.

Mark Meriaux, Accreditation and Technical Manager for the Natural Stone Institute commented: “It is important for fabricators to comprehend the health risks involved with silicosis, both personally and for employees, and to understand what can be done to minimize the risks. There is currently at least one documented case of silicosis in California tied to a fabrication shop, so now is the time to get this message out to fabricators. We look forward to working with NIOSH to share this message.”

To register for this free webinar, contact [email protected] or visit www.naturalstoneinstitute.org/NIOSH.




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