TCNA: By the Book – May 2017

Changes to the 2017 TCNA Handbook address a wide spectrum of issues

Now in its 54th year of continuous publication and slated for release this month, the TCNA Handbook for Ceramic, Glass, and Stone Tile Installation, a compilation of guidelines widely-used in specifying, selling, and installing tile and related installation materials, will include this year many noteworthy changes to existing language as well as wholly new sections. All are aimed at providing more guidance, and improving understanding and problem solving with regard to tile installations.

Referring to the revisions: “They run the gamut,” said Stephanie Samulski, the Handbook technical content manager and secretary of the Handbook Committee for Tile Council of North America (TCNA), which publishes the Handbook. “Anyone specifying, selling, designing, installing, superintending, or otherwise involved with tile should update their technical library with the new edition,” she said. “With the range of new content ratified by the Handbook Committee, there’s something relevant to essentially anyone and everyone working with tile.”

TCNA executive director and Handbook Committee chairman Eric Astrachan gives as examples the new sections “Tile Layout Considerations” and “System Modularity,” which are geared more toward those involved in tile selection and design. As an example of the various revisions to Handbook existing language, he noted the further explanation this year of substrate flatness requirements, which Astrachan calls “essential but too-often ignored.”

Astrachan explained that the Handbook is a vehicle for providing industry consensus, but it’s not a standard and therefore not set up like one, enabling the committee to provide information in non-mandatory language when needed. It’s a particularly useful means of addressing conflicting recommendations or specifications, as can easily occur when a producer or another trade makes a major shift in product or practice in a way that impacts tile installations.

A prime example is the new Handbook section to address the newer type of steel studs commonly referred to as “equivalent gauge” or “EQ” studs. The new Handbook language helps people understand the most important considerations for avoiding tile problems when these thinner studs are used. Samulski noted that “the specific design criteria that are ultimately needed will likely get hashed out in ANSI.”

Other noteworthy changes that 2017 Handbook users will see include significantly more information on how to avoid the undesirable effects of wall-wash lighting on tile installations, new “Visual Inspection of Tilework” and “Design Considerations When Specifying Tile” sections, significant changes to the EJ171 movement joint guidelines, and a new method for tiling an exterior deck or balcony over unoccupied space (tile and stone versions).

To purchase the 2017 TCNA Handbook, visit

Tile Industry Launches Inspiration and Education Initiative; Why Tile Debuts Here at Coverings




The tile industry has united in a marketing and education initiative designed to inspire consumers and provide information on all of tile’s benefits. The campaign, called Why TileSM, is being introduced to the industry here at Coverings.

Why Tile is an industry effort with input sought from various industry organizations including the Ceramic Tile Distributors Association (CTDA), the National Tile Contractors Association (NTCA), the Ceramic Tile Education Foundation (CTEF), the Tile Contractors Association of America, and the Tile Heritage Foundation (THF), in addition to manufacturers worldwide. Why Tile is coordinated by the Tile Council of North America (TCNA).

“We’re so pleased to give Why Tile a ‘friends and family’ introduction here at Coverings,” says Eric Astrachan, Executive Director, TCNA. “In developing Why Tile, we’ve had the pleasure of reaffirming everything that’s so wonderful about tile. With Why Tile, we’ll be delivering this messaging to consumers and to the A&D community as never before and in new and impactful ways – most notably, through the website, WhyTile.Com.” provides extensive messaging on the benefits of tile, centering on four main tenets: Design, Easy Care, Healthy Spaces, and Heritage. The site features an Inspiration Gallery; downloadable Project Guide, schematics, and maintenance tips; and a Test Your Tile IQ feature where users can take a simple 10-question quiz for a chance to win a prize.

“As with any website, WhyTile.Com will constantly evolve and provide a means for our audiences to derive inspiration and access planning resources – we want this to be both engaging and a helpful tool,” says Kathy Meyer, Marketing Director, TCNA. “We’re excited to get out there with Why Tile, and this is just the beginning of what I know will be a long and colorful story.”

“Developing Why Tile even to this nascent stage has been very rewarding, in that it is the culmination of the vision of such a diverse group coming together – including competitors, and folks who would normally never be around a table together – in a cooperative manner I’ve never seen in nearly 30 years in marketing and advertising,” says Julie Peck, Creative Director, TCNA. “We’re proud of the work we’ve done to date, and look forward to refining and

expanding upon it with the further input of our partners and the industry as it is introduced here at Coverings.”


ANSI Standards:
a tile installer’s best friend!


By Scott Carothers,
CTEF director of Certification and Training

How familiar are you with the ANSI American National Standards Specifications for the Installation of Ceramic Tile? (ANSI stands for the American National Standards Institute.) If you aren’t, and you’re in the tile installation business, it’s time you pay attention. ANSI Standards are a tile installer’s best friend!

Why tile installers should study the TCNA Handbook and ANSI Specifications
For continued success, tile installers should study the TCNA Handbook for Ceramic, Glass and Stone Tile Installation and ANSI Specifications, retaining as much as possible, or at least knowing where to find the answers. These books can be your best friend as this article – based on a true story – explains.
Here’s how the story goes.


After successfully completing the Large Format Tile and Substrate Prep test – one of the  ained in the Advanced Certifications for Tile Installers (ACT) program – an installer returned to work installing tile while also being the jobsite superintendent.
On this particular day, the superintendent was representing his company at a pre-job conference with the architect since the business owner was not available.
The architect reviewed the scope of the job involving the tile installation and said that the job included a 12” x 24” non-rectified porcelain tile which was specified to be installed in a running bond (brick pattern), at a fifty percent offset and a 1/32” grout joint.

When current ANSI Specifications call for a different application
The now ACT-certified installer politely informed the architect that the current ANSI Specification, A108.02 under section 4.3.8, calls for a much different application.
Here follow the criteria excerpted from ANSI A108.02 Section 4.3.8 regarding grout joint size, particularly in relation to the tile size, dimensional precision, and offset pattern:

4.3.8 Grout Joint Size:
To accommodate the range in facial dimensions of the tile supplied for a specific project, the actual grout joint size may, of necessity, vary from the grout joint size specified. The actual grout joint size shall be at least three times the actual variation of facial dimensions of the tile supplied. Example: for tile having a total variation of 1/16” in facial dimensions, a minimum of 3/16” grout joint shall be used. Nominal centerline of all joints shall be straight with due allowances for hand-molded or rustic tiles. In no circumstance shall the grout joint be less than 1/16”. Running Bond/Brick Joint Patterns:
For running bond/brick joint patterns utilizing tiles (square or rectangular) with any side greater than 15”, the grout joint shall be, on average, a minimum of 1/8” wide for rectified tiles and, on average, a minimum of 3/16” wide for calibrated (non-rectified) tiles. The grout joint width shall be increased over the minimum requirement by the amount of edge warpage on the longest edge of the actual tiles being installed. For example, for a rectified tile exhibiting 1/32” edge warpage on the longest edge, the minimum grout joint for a running bond/brick joint pattern will be 1/8” + 1/32” or 5/32”, on average. Of necessity, in any installation, some grout joints will be less and some more than the average minimum dimension to accommodate the specific tiles being installed. Running Bond/Brick Joint Offset:
For running bond/brick joint patterns utilizing tiles (square or rectangular) where the side being offset is greater than 18” (nominal dimension), the running bond offset will be a maximum of 33% unless otherwise specified by the tile manufacturer. If an offset greater than 33% is specified, specifier and owner must approve mock-up and lippage.

The ANSI Standard-based solution
The installer paraphrased the ANSI specification saying, “The tile is to be installed in a running bond offset at a maximum of 33% with a 3/16” grout joint.”
The architect asked the installer where he found this information and how he knew it so well. The installer showed the architect the portion of the ANSI book containing that standard, and told him that he became aware of this and many other aspects of the industry standards through his studies in preparation for the ACT certification tests. The architect reviewed the ANSI listing and agreed that the specifications would be modified to follow the standard that the installer had described. The tile was installed successfully and everyone involved was satisfied with the end result.
The owner of the tile company, who was absent through this process, is convinced that had they installed the tile as originally specified, the job would have been rejected due to edge lippage, requiring it to be removed and replaced.

Get to know the tile installer’s best friend!
The ANSI Standards-based knowledge saved this contractor a significant amount of time and potential expense. Using knowledge wisely can reap large benefits. Wouldn’t you agree?
Have you encountered tile installation situations where the ANSI Standards were truly your best friend? Please share your experiences with us at [email protected]

The Ceramic Tile Education Foundation (CTEF) is an educational institution that offers local, regional, and national training programs for consumers, installers, construction professionals, architects, designers, building inspectors and sales associates interested in the sale and installation of ceramic tile. Find out more at


TCNA By The Book: Membranes in Steam Shower/Steam Room Application

btb-01Dan and Elizabeth Lambert of Lambert Tile and Stone, located in the Vail Valley of Colorado, have been providing high-end residential tile installations since 2000.

At Lambert Tile and Stone we install around 30 residential steam showers per year in the mountains of Vail, Colo. Thanks to technology, our steam showers and steam rooms have evolved over the past number of years with better insulating and lower vapor-permeance qualities.

Regardless of steam room/steam shower design, it is critically important that the enclosure incorporates the correct membrane, since not all membranes are suitable for high-temperature and steam applications.

Regardless of steam room/steam shower design, it is critically important that the enclosure incorporates the correct membrane, since not all membranes are suitable for high-temperature and steam applications.

Steam rooms and steam showers have been a popular option in ski resort communities. Resort and hotel spas, as well as fitness centers, offer this amenity for the health benefits steaming provides. This luxury benefit has enticed many people to incorporate steam units into their own homes, and this trend is growing in popularity.

Ninety percent of the steam showers we construct are not continuous-use steam rooms, but master bath and guest suite showers designed with the option to have steam while the occupants shower. Since 90% of our assemblies include rain heads and body sprays, these steam shower designs usually opt for level ceilings. But all of our commercial and residential continuous-use steam rooms are designed with the 2” per foot ceiling slope that is shown in TCNA Handbook methods SR613 and SR614, to minimize condensation from dipping onto occupants.

Regardless of steam room/steam shower design, it is critically important that the enclosure incorporates the correct membrane, since not all membranes are suitable for high-temperature and steam applications. Consult with your technical services department of the manufacturers of materials you are considering to ensure compatibility and permeance performance of the membrane.

Thanks to technology, the Lambert's steam showers and steam rooms have evolved over the past number of years with better insulating and lower vapor-permeance qualities.

Thanks to technology, the Lambert’s steam showers and steam rooms have evolved over the past number of years with better insulating and lower vapor-permeance qualities.

The TCNA Handbook for Ceramic, Glass, and Stone Tile Installation contains two methods. Method SR613 is for steam room installations over concrete or masonry, and SR614 is for installations over wood or metal studs. Both methods require a low-perm waterproof membrane meeting ANSI A118.10 applied in a manner specified by the membrane manufacturer to provide a water-vapor permeance rating of 0.5 perms or less. If a perm rating of 0.5 or less is not achievable, the TCNA Handbook also recommends the use of a vapor retarder with a perm rating of 0.1 or less behind the wall assembly. Keep in mind that integrated bonding flange drains should not be used if the vapor retarder behind the wall assembly is required. Waterproofing should not be confused with vapor retarding.

Organic mastics should never be used in either steam room or steam showers and the use of natural stone in steam environments should be extremely cautioned.

Dan and Elizabeth Lambert of Lambert Tile and Stone located in the Vail Valley of Colorado have been providing high-end residential tile installations since 2000. Dan is a Regional Board Director for the NTCA and sits on the NTCA Methods and Standards Committee and the Technical Committee. Lambert Tile and Stone is a NTCA Five Star Contractor and employs Certified Tile Installers (CTI). Certifying our employees is so important to us that we hosted our own testing site at our warehouse with support from our local community who provided us with the lumber to build our own testing modules. The local tile stores and distributors sponsored all our meals for two days. Having the CTI designation has been a great tool to show our builder community how we support, test and educate our employees.

By the Book – July 2016

brought_by_CTEFCeramics vs. Porcelain: Examining Performance, Assessing Needs of the Consumer

book-01by Marianne Cox, director of marketing, Interceramic USA

In an industry where we are conditioned to believe that porcelain is far superior to ceramic, we must ask ourselves if this is a true statement. Why? Because it is not.

There is no disputing that any form of tile (ceramic or porcelain) can be manufactured poorly while others are manufactured reputably. There is also no disputing that ceramic and porcelain live on opposite ends of the price spectrum. How do we fairly compare the two? We must discard two trains of thought. First, technically speaking, we eliminate from consideration any tile that does not meet ANSI A137.1. If tile fails to meet these standards, we should never consider it for any installation (Exception: some specialty tiles where the performance parameters are not relevant, such as using Saltillo tile in some residential installations). Second, let’s eliminate the thought that the goal is to make money or upgrade for sake of making money, with no thought to the needs of the homeowner.

Concrete-look Basole from Interceramic is an example of a high-density ceramic that has comparable performance characteristics as porcelain: freeze/thaw resistant, suitable for exterior use, stain and thermal shock resistance, chemical and crazing resistant and suitable for commercial application.

Concrete-look Basole from Interceramic is an example of a high-density ceramic that has comparable performance characteristics as porcelain: freeze/thaw resistant, suitable for exterior use, stain and thermal shock resistance, chemical and crazing resistant and suitable for commercial application.

Before we address what should be the true debate of the ceramic vs. porcelain conundrum, we should address the technical attributes of ceramic tile. ANSI A137.1 clearly defines TILE as “a ceramic surfacing unit, usually relatively thin in relation to facial area, having either a glazed or unglazed face and fired above red heat in the course of manufacture to a temperature sufficiently high to produce specific physical properties and characteristics.” Porcelain is defined as a “type” of ceramic tile, and the only differentiation between the two as outlined in ANSI A137.1 states porcelain is “a ceramic tile that has a water absorption of 0.5% or less that is generally made by the pressed or extruded method…”.

That’s it. The only difference. All other technical attributes from breaking strength to abrasion resistance offer clarity to the performance of the tile over a period of time. Therefore, some ceramics may perform as well as or better than some porcelain without meeting the </= 0.5% water absorption criteria that separates the two. It should be clear that ceramic tile, depending on how it is manufactured, will perform at different levels, some better than others. The same can be said for porcelains as well.

Burano has a vein-cut travertine look in four colors of ceramic tile with a Victorian mosaic. The line is enhanced by Lumen FX, which is applied in conjunction with the veining for a shimmer effect.

Burano has a vein-cut travertine look in four colors of ceramic tile with a Victorian mosaic. The line is enhanced by Lumen FX, which is applied in conjunction with the veining for a shimmer effect.

Ceramic performance criteria and the needs of the consumer

Let’s focus on the performance of ceramic tile. Can some ceramic tiles, manufactured by innovative companies, perform at the level of porcelain? Is it possible for some ceramics to test at or higher than porcelain for breaking strength? Yes. Is it possible for some ceramics to test at or higher than porcelain for abrasion resistance? Yes. Can some pass the freeze/thaw test? Yes. Meet or exceed threshold for DCOF? Yes. Can some ceramic tiles be installed outside? Yes! Yes!

Now, going beyond the tech talk, where does that leave us? It means we satisfy the NEEDS of the customer. Even if we break it down into residential vs. commercial, it is still not black and white.

Sure, some commercial installations may require more technologically advanced porcelains, like an unglazed through-body porcelain. However, most commercial projects do not. There are ceramic tiles offered in the U.S. with low water absorption, high breaking strength, superior scratch resistance and that can be installed outside. These ceramics will certainly hold up under the conditions found in many commercial installations.

San Giulio ceramic tile offers a striking stone movement in four matte colors and 12” x 12” matching mosaic sheets. Field tile is 16” x 16” and 12” x 24”.

San Giulio ceramic tile offers a striking stone movement in four matte colors and 12” x 12” matching mosaic sheets. Field tile is 16” x 16” and 12” x 24”.

Residentially, the NEEDS of the customer should be the primary goal. Homeowners are typically upgraded from ceramic to porcelain during the selection process. They are told that porcelain is going to outperform and outlast ceramic tiles. That’s not necessarily true. Many ceramics today are produced using similar raw materials, fired at the same temperature, and use the same printing and glazing processes. Many ceramics today will perform as well and last as long as most porcelains. Many ceramics today meet the needs of the homeowner in terms of on-trend designs and durability, yet offered at an affordable price. That means they often have better designs than porcelain, perform like porcelain and last as long as porcelain. Aside from the obvious, why push a homeowner to porcelain?

For example, when choosing windows for your new home, if you are given the choice of the standard durable windows or upgrading to bullet proof glass, realistically, what would you choose for your home?

The takeaway? Find a reputable ceramic tile manufacturer that will provide you with fact-based information to support the obvious…ceramic is an option to porcelain for most of your residential and commercial projects. You’ll have an opportunity to provide your customers with the beautiful product they desire, at a value. If you need advice on where to start your search, feel free to connect with me at [email protected].

By the Book – May 2016

brought_by_CTEFElectric floor warming

may-bythebook-01By Arthur Mintie, senior director, Technical Services, LATICRETE International, Inc.

Electric radiant floor warming continues to be a growing trend in the tile and stone industry. There are multiple details/methods in the TCNA Handbook for Ceramic, Glass and Stone Tile Installation that relate to electric floor warming, such as RH115(A), RH116(A), RH130, RH135, RH140, and more.

Here are some basics, to begin with: heat energy, emitted from an electrically warmed floor, warms people and other objects in the room rather than directly heating the air within that space. Because of this, the temperature of the internal air within radiant-heated spaces is generally lower than spaces heated via conventional methods. Yet, the same degree of body comfort is achieved, so the temperature perceived by those in the room is actually the same. As a result, the amount of electricity used to warm a room equipped with radiant floor warming is much less than one would expect, making the system very energy efficient.

Electric floor warming is designed to be installed directly under the tile or stone flooring for both new construction or remodeling projects. Installers may simply thin-set this material down to the substrate, while adding virtually no height to the floor (roughly 1/8” [3mm]).

The installation of an electric in-floor warming system does not require any special tile installation procedures. The substrate / subfloor should be prepared as for any conventional tile installation according to applicable standards. Very importantly, it should be clean of any debris or sharp objects that could damage the heating element. The heating system should be installed over a smooth and even surface. Concrete, mortar beds, exterior glue plywood, existing ceramic tile and stone, cement terrazzo and cement backer board provide ideal substrates for electric radiant floor warming installations.
For the most part, electric floor-warming components consist of a heating mat with cables (or loose wire cables), which is installed right beneath the tile and stone surface, and a wall-mounted thermostat. Today’s simple-to-use, digital and programmable thermostats generally have been designed for installation in conjunction with the same company’s floor warming cable mats. It makes sense to use a heating element as well as a thermostat from the same firm, as well. That way, users have the confidence of purchasing a product with components covered by a “single source.”

Installing the system

Surprisingly to many, the entire installation process is easier than you might think. To begin with, one should make a scale drawing of the floor plan, mapping out the “walking area” where the heating mat will be positioned. It should not be placed under or closely adjacent to cabinets, tubs and showers. Additionally, it should be at least 6” (150 mm) away from wax toilet seals. If needed, technical assistance is quickly available from key manufacturers, whose support staff generally can determine the optimal layout and quantity of the heating mat. There are software layout tools available, as well. For example, some select radiant heat manufacturer engineers have created simplified software layout tools, which makes adding radiant floor heating virtually effortless, allowing even a beginner to complete a floor heating layout in minutes.

The radiant heat system should be checked at various times during the installation process to ensure that no shorts, cuts or other damage has occurred to the heating element. Some manufacturers include a fail-safe element that will warn the installers if a short has occurred. Make sure to follow the manufacturer’s step-by-step installation process to ensure that the integrity of the system is maintained from start to finish.

may-bythebook-02Once the heating mat is put in place and all electrical work is complete, what comes next is the tile installation. While most electric floor-warming systems on the market today are compatible with any tile finish, there are certain installation products that work better than others. In particular, high performance ANSI A118.15-compliant latex thin-set mortars are designed for optimal performance when used in conjunction with electric floor-warming systems (ANSI A118.4 compliant latex thin set mortars are allowed when an appropriate membrane is used). In addition, the use of self-leveling underlayments (e.g. TCNA Methods RH 116(A) & 140) can also be used to encapsulate electric floor warming systems when the substrate requires attention. Finish off the tile installation with an appropriate ANSI 118.6 or better cement-based grout or an ANSI A118.13-compliant epoxy-based grout for even better performance and ease of maintenance.

Cautions with electric flooring-warming installations

  • Cure time – Allow at least a 3-to-7 day cure period after the final grouting period before activating the floor-warming system. This will allow all of the installation components adequate time to cure out and reach sufficient strength. If there is any doubt on this matter, consult with the electric heat and tile installation materials manufacturer for their guidance. Typically, the cure-period question arises during installations that require quick return to service times (e.g. bathroom or kitchen remodeling).
  • Expansion joints – Since the heating and cooling of floors occurs at more frequent intervals with heated floors, the inclusion of movement joints is mandatory. In fact, in many cases, placing the movement joints in accord with the exterior recommendations of TCNA EJ171 is a good idea.
  • Troubleshooting – In addition to manufacturer-specific instructions on troubleshooting electric radiant heat system, the National Tile Contractors Association (NTCA) includes a troubleshooting section in its NTCA Reference Manual on this topic that can be consulted for common issues that might occur. The chapter is titled “Radiant Heat Issues for Tile & Stone Installations,” located on pages 159-160 of the 2015/2016 manual. As is the case with many sections in the publication, valuable and practical guidance is provided to assist installers with these applications.

may-bythebook-03It is important to the end user to select an electric floor warming system with comprehensive warranty coverage that includes both labor and materials.

Electric floor warming (both in mat type or loose wire configuration) is a cost-effective warming solution upgrade that creates a comfortable environment Keeping your customers warm and content results in positive feedback, great referrals and ultimately, repeat business.

Arthur Mintie serves as the senior director of Technical Services for LATICRETE International, Inc. LATICRETE INTERNATIONAL, Inc. is a proud sponsor of the Ceramic Tile Education Foundation and is actively involved in global training efforts of the tile and stone industry.

Photos: Courtesy of LATICRETE International, Inc.

By the Book – March 2016

brought_by_CTEFCurbless shower design: requirements and options

514-pompoBy Donato Pompo, CTC, CSI, CDT, MBA, Ceramic Tile and Stone Consultants (CTaSC); University of Ceramic Tile and Stone (UofCTS)

Curbless showers are showers without a raised shower dam as is traditionally found in tiled showers. Initially, curbless showers were necessary to facilitate shower access by wheelchair users, particularly in public facilities like hotels and hospitals. Now curbless showers are popular for their look.

To ensure successful installation of this increasingly in-demand shower style, specifiers and installers must know the requirements and options for constructing them. With the dam removed to make a shower “curbless,” it becomes extremely important to utilize alternate means for managing the water, which is accomplished primarily through slope, waterproofing, and water-containment techniques. A few things I always recommend are:

  • Ensure the shower floor is sloped 1/4” per foot toward the drain. This can be difficult when the drain is in the center of the shower floor. Linear trench drains are getting more popular since they can be located at the back of the shower, which is more practical for providing floor slope and accommodating a wheelchair. Many also find them more aesthetically pleasing.
  • The bathroom floor outside the curbless shower must be the high point of the room so water can drain toward the shower.
  • The bathroom door threshold can act as a quasi-dam, to prevent water that migrates outside of a curbless shower from migrating outside of the bathroom entirely.
  • All transitions and penetrations in the room must be sealed with an ASTM C920 sealant.
  • Proper construction of accessible and curbless showers can be tricky, due to the many codes and standards that must be referenced to ensure compliance. There are national and international building and plumbing codes, local codes, and tile industry guidelines. Any combination of these may apply to any given shower. If, in addition to being code-compliant, a curbless shower must also be handicap-accessible, there are also the federal requirements of the Americans with Disability Act (ADA), given in the 2010 ADA Standards for Accessible Design.

To ensure successful installation of the increasingly in-demand curbless shower style, specifiers and installers must know the requirements and options for constructing them.

To waterproof or not to waterproof, that is the question

Recently, required waterproofing of bathrooms adjacent to curbless showers has been a topic of discussion, likely resulting from a change to the 2015 Uniform Plumbing Code (UPC), Chapter 4 Section 408.5, which now says: “The immediate adjoining space to showers without thresholds shall be considered a wet location and shall comply with the requirements of the building, residential and electrical codes.” Some interpret that to mean that such areas must be waterproofed. I do not interpret the code change that way, as there are no requirements given in International Building Code (IBC), International Residential Code (IRC), or Electrical Code to waterproof wet areas. The interpretation that waterproofing is required likely stems from thinking of wet area requirements in the context of tile industry practices, which often relates to waterproofing.

UPC lists one variety of curbless shower – those designed to their accessibility standards – as an exception to its aforementioned requirement to follow IBC, IRC, and Electrical Code. These showers are instead subject to design criteria given in a table (Table 1701.1), but none of the requirements in that table refer to waterproofing either.


Curbless shower methods B421C (shown) and B422C, are voluntary guidelines. They require a continuous bonded waterproof membrane on the floor and walls of the shower itself, with that waterproofing extending outside the shower at least one foot beyond the high point of the floor.

Likewise, the 2016 TCNA Handbook does not require full waterproofing of a curbless-shower-adjacent bathroom. Curbless shower methods B421C and B422C, which are voluntary guidelines, require a continuous bonded waterproof membrane on the floor and walls of the shower itself, with that waterproofing extending outside the shower at least one foot beyond the high point of the floor; additional waterproofing outside the shower is suggested as a consideration, but not required.

Nonetheless, although my interpretation is that waterproofing of a bathroom adjacent to a curbless shower is optional, I always strongly recommend full waterproofing of the floor, with the waterproofing flashing up the walls at least 3”, to avoid water damage in those areas. I have found that when consumers become aware of the option to waterproof the entire bathroom floor or not, they will pay the added cost for the added value and protection. On the other hand, when consumers were not given the option, and then have a leak incident


This is an example of a ceramic tile curbless shower adjacent bathroom floor sloped the wrong way. Proper installation should have the floor sloped towards the shower drain.

in their bathroom that resulted in water traveling below through ceilings and into adjacent rooms causing great collateral damage, they are very unhappy with their tile supplier or installer for not giving them a choice. So you are doing a disservice to your customers if you don’t give them a choice, which at the same time helps limit your liability.

Is a curbless shower allowed?

Interestingly, while some codes address how to construct a curbless shower, others address whether a curbless shower is even allowed. Some local codes prohibit curbless showers due to how they interpret the UPC, while other local codes provide guidelines, with some requiring that adjacent bathroom floors be waterproofed as a continuation of the shower. In such cases, waterproofing of a bathroom adjacent to a curbless shower goes from recommendation to requirement due to local code being more stringent and specific than UPC.


This natural stone tile curbless shower has the adjacent bathroom floor sloped the right way towards shower drain.  The waterproofing under the stone was continued up the wall 3” at the base. These two measures help contain water in the event of a leak, preventing expensive water damage to adjacent areas and beyond.

In addition to UPC, several other building codes address shower construction: International Plumbing Code (Section 417), International Residential Code (Chapter 27, Section P2708), and International Building Code (Chapter 11, Accessibility Section 1107.6.1.1, Chapter 25 sections 1210, 2509, and 2511). Although they, too, leave waterproofing of bathrooms adjacent to curbless showers optional, it’s important to be familiar with their requirements to ensure shower compliance in all other respects.

When utilizing codes and guidelines, be sure to reference the correct edition. Code bodies have “code cycles” for making changes and updates, and states, counties, cities, etc., adopt and adapt codes on their own timelines. Often, the code in effect in a given locale is not the most current version available, making it even more challenging to construct a curbless shower “by the book.”


This natural stone tile curbless shower adjacent bathroom floor is sloped the right way towards shower drain. The level demonstrates that the shower receptor is sloped towards the drain, located in the back of the shower.  


Donato Pompo, CTC, CSI, CDT, MBA, is the founder of Ceramic Tile and Stone Consultants (CTaSC), and of the University of Ceramic Tile and Stone (UofCTS) – a Bronze sponsor of CTEF. He is an NTCA-recognized industry consultant who specializes in shower failure investigations and architectural shower installation specifications.

Tile industry standards: essential tools for sale and installation of ceramic tile

brought_by_CTEFBY THE BOOK – January 2016

By Bart A. Bettiga,  NTCA executive director

By Bart A. Bettiga,
NTCA executive director

Innovation in ceramic tile and installation materials manufacturing has revolutionized the tile industry. Tile is now available in very large and slimmer formats (thin porcelain tile and panels), and multiple size options, utilizing many different materials such as ceramic, porcelain, glass, metal, stone, etc.

This variety in format and manufacturing has created multiple creative opportunities for design and specification, opening the way for our products to be used in interior and exterior spaces that were traditionally considered unsuitable for tile or stone. Indeed, there are many reasons that the future is bright for our industry, and we have technology to thank for this. But this same innovation is creating our greatest challenge as well, as we swiftly have to develop standards for these products and properly communicate this information to the tile industry.

The Tile Council of North America (TCNA) and the National Tile Contractors Association (NTCA) offer essential industry standards, guides and reference materials to help you stay current with the industry. That being said, standards are developed after products have a proven track record of success, so it is also important to work closely with manufacturers and distributors when new technology is introduced. Decisions to specify, sell or install products without standards should be closely examined, and specific product recommendations and warranty information should be documented and followed.

Any company involved in the sale or installation of ceramic tile and natural stone tile should make sure they have these materials available to them. Both associations offer their resource materials at very affordable prices, and spend thousands of dollars annually to maintain the documents to keep them current.

Many people are unaware of the incredible value and information these documents offer. Knowledge is power, and in many instances, it is also money. Many installation failures and tear outs could have been avoided if people paid attention to the standards available to them or used the information to their advantage when navigating through a problem that may or may not have been their responsibility.

Although reference materials can be complex, there are three basic elements they were created to address.

  1. Specification and design considerations
  2. Installation requirements and recommendations
  3. Building and construction requirements and preparation by other trades

Each document or standard has a specific purpose, and it can be challenging to understand what materials you should order. The following information is a guide to available resources to assist you in deciding what you need. Some of the materials are available in book, CD or digital download options, so pay close attention to that information when you visit the website

NTCA_RMNational Tile Contractors Association Reference Manual

Use to prevent failures and troubleshoot problems in the field

This problem-solving manual is a comprehensive culmination of knowledge, and research and development of the NTCA Technical Committee members, ceramic tile contractors, distributors, manufacturers and others allied to the ceramic tile industry. Letters and templates used to communicate and document jobs are included. The NTCA Reference Manual is essential for distributors, manufacturers and retailers who are asked to look at project complaints, as well as tile and flooring contractors. The NTCA Reference Manual was designed to complement the TCNA Handbook and ANSI Standards.

TCNA Handbook for Ceramic, Glass, and Stone Tile Installation

TCNA_handbookClarifies and standardizes installation specifications

This guide details installation recommendations – or methods –required for a given set of products and applications. It explains the properly-designed, -constructed, and -prepared substructure using materials and construction techniques that meet nationally-recognized material and construction standards.

Included are:

  • Product selection guides for ceramic, glass, and stone tiles
  • Guidelines for wet areas
  • ISO mortar and grout specifications
  • Information on substrate flatness requirements
  • Information on grout joint sizes and patterns, and workmanship standards excerpted from ANSI installation standards.

ANSI A108-A118-A136.1 

ANSI-A108American National Specifications for the Installation of Ceramic Tile 

Provides voluntary standards for the installation of ceramic tile 

American national standard specifications A108.01, .02, .1A, .1B, .1C, .4, .5, .6, .8, .9, .10, .11, .12, .13, .14, .15, .16, and .17 define the installation of ceramic tile.

A118.1, .3, .4, .5, .6, .7, .8, .9, .10, .11, .12, .13, .15, and A136 define the test methods and physical properties for ceramic tile installation materials.

These standards are intended to be referenced or included in the ceramic tile sections of project specifications.

ANSI A137.1-2012 American National Standard Specifications for Ceramic Tile 

ANSI-A137-1Details voluntary standard specifications for ceramic tile

This publication lists and defines various types, sizes, physical properties, and grading procedures for ceramic tile, including mosaic tile, quarry tile, pressed floor tile, glazed wall tile, porcelain tile, trim units, and specialty tile. This standard provides quality criteria for buyers, specifiers, installers, manufacturers, and the public in general. It is intended for reference or inclusion in the ceramic tile section of project specifications and contracts.

Note: This standard includes the new testing method and requirement for dynamic coefficient of friction (DCOF).

ANSI A137.2-2013 American National Standard Specifications for Glass Tile

ANSI-glassLists voluntary standards and definitions for glass tile

This voluntary standard lists and defines various types, sizes, and physical properties for glass tile. Some of the key issues addressed by the standard are:

  • Methods of manufacture
  • Categorization by size
  • Mounting criteria for mounted glass tiles
  • Definitions and test procedures for measuring translucence
  • Strength criteria
  • Thermal shock resistance using real life temperature ranges
  • Levels of recycled content

This standard provides quality criteria for buyers, specifiers, installers, manufacturers, and the public in general. It is intended for reference or inclusion in the glass tile section of product specifications and contracts.

ANSI-greenIn addition to these materials, the TCNA released versions 1 and 2 of ANSI A138.1, which addresses Green Squared (the industry standard for sustainable tile and installation products). Also in development is both a product and installation standard that will address Thin Porcelain Tile and Thin Porcelain Tile Panels.

For more detailed information on ANSI standards and the TCNA Handbook, go to For information on the NTCA Reference Manual, visit the NTCA website and store at

By the Book – September 2015


New classifications added to the 2015 TCNA Handbook to identify submerged installations

whitfieldBy Jim Whitfield FCSI, LEED AP; MAPEI manager of Technical Services

In 2011, the TCNA (Tile Council of North America) Handbook Committee replaced the wet area classifications in the Wall Tiling Installation Guide with new, more specific Environmental Classifications.

Previously, the TCNA Handbook for Ceramic, Glass and Stone Tile Installation only classified methods as suitable for dry, limited water exposure, or wet conditions. The classifications introduced in 2011 and still in use are: Res1 and Com1 (dry conditions), Res2 and Com2 (limited water exposure), Res3 and Com3 (wet conditions), Res4 and Com4 (high humidity, heavy moisture), Res5 and Com5 (high temperature), and Res6 and Com6 (exterior).

BtB-1This revision, formulated by the TCNA Backer Board Subcommittee, added clarity to the TCNA Handbook by better defining the conditions that each installation method can be expected to withstand, particularly with respect to heat and moisture exposure. With the 2011 revision, a design professional could more easily select a TCNA method for residential and commercial construction to accommodate the expected conditions.

In 2015, the classifications Res7 and Com7 – for submerged conditions – were added to further improve the Handbook’s Environmental Exposure Classification system. As one  would expect, the new Res7 and Com7 classifications were added to the three Handbook pool methods: P601MB-15, P601TB-15, and P602. In making this addition, the classifications already attached to these methods (Res3, Res4, Res6, Com3, Com4, and Com6) were not removed, as Handbook methods often have multiple classifications to denote the various expected conditions. For example, an indoor enclosed pool with a tiled deck is subjected to high humidity and heavy moisture, consistent with the Res4 and Com4 Classifications. Similarly, many pools are exterior, making the Res6 and Com6 classifications applicable.

When you see Res7 or Com7

A main consideration for submerged installations is product selection, as not all mortars, grouts, tile, etc., are suitable. Mortar manufacturers typically recommend thinset mortars meeting ANSI A118.15 or ISO C2S2, as listed in the Handbook pool methods.

BtB-2For ceramic tile, the ANSI A137.1 standard for ceramic tiles says that, when using sheet-mounted tile, only certain types of sheet-mounted tiles are suitable for use in pools and other Res7 and Com7 areas. Specifically, it says, “Tile manufacturers must specify whether back-mounted or edge-mounted tile assemblies are suitable for installation in swimming pools, on exteriors and/or in wet areas. Back-mounted tile with paper on the back side shall not be installed in wet areas.”

In communicating whether or not a particular line of mounted mosaics may be used in pools, some manufacturers differentiate between the waterline and the area below the waterline, and allow some sheet mounted tiles to be used at the waterline, but not below.

There is no restriction in ANSI A137.1 regarding the use of unmounted ceramic tiles in submerged installations.

BtB-3For glass tiles, in order for a tile to meet the A137.2 glass tile standard, it must achieve a minimum bond strength of 100 PSI after a week of submersion. This is because achieving good bond, especially in wet conditions, is more challenging for glass tile than for ceramic. According to the standard, the test method for evaluating shear bond strength of glass tile “provides a means of determining whether or not a glass tile or mounted glass tile assembly can be bonded with adequate strength in dry and submerged conditions.” So, when glass tile is to be used in a Res7 or Com7 area, it’s important to verify that the glass tile meets A137.2. Additionally, the glass tile standard states that, for glass tiles mounted onto sheets, face-mounted sheets are recommended for submerged applications because “face-mounting of mosaics to a sheet allows bonding to the back of the tile without interference from any mesh, glue, or other material used with back-mounted or edge-mounted mosaics,” (A137.2 Section

BtB-4These references to tile suitability for submerged areas – in the ceramic tile and glass tile standards – highlight the importance of careful product selection when following a Handbook installation method that carries the Res7 or Com7 designation. In improving the specificity of the Environmental Exposure Classifications by adding a means of designating installations that will be submerged, the Handbook Committee has succeeded in improving product selection guidance for design professionals, distributors, contractors and others involved in the specification and product selection processes.


Jim Whitfield FCSI, LEED AP is the manager of Technical Services at MAPEI. MAPEI has been actively involved with the CTEF, contributing to study materials, hosting certifications at its locations and sponsoring at the Signature level. Whitfield is actively involved in the tile industry standards as vice president of the MMSA (Materials, Methods and Standards Assoc.), and a member of both the TCNA Handbook Committee and the NTCA Technical Committee.

TCNA Handbook: new methods for curbless showers


joe_kerber“They just don’t build them like they used to.”

You’ve all heard that before, and most of the time that’s a good thing.

With our never-ending desire to have the “latest and greatest,” or the “biggest and best,” we continue to develop new ideas and challenge ourselves to help meet our customer’s wants and needs. Some of these ideas are thinner floor systems, and larger, curbless showers. Our manufacturing partners in the tile industry have been developing new products over the years to help us make this all happen.

There are three products that stand out in my mind as great inventions that have really advanced the tile industry: cement backer units, thin-set mortars, and today’s subject, topical waterproofing.

I was first introduced to topical waterproofing in the 1970s. I remember the old guys at the time saying, “What the hell is that crap?” Being the forward thinker that I am, I would say, “I’m going to try this stuff.” So I did. My wife Wendi and I were just starting to build our first new house. The building inspector at the time was an acquaintance of mine and when I approached him with the idea of a tiled tub in my house he said, “It’s your house, go ahead.” So we did. The many tiled tubs from that era are still in service today. I have been using topical waterproofing ever since. It is the one product that has really changed our design criteria.

Next challenge: if we can slope enough floor space on a bath floor so that the water from a shower runs toward a drain, do we need a curb? The answer is no. The issue that we had is that according to the IPC (International Plumbing Code) there had to be a “dam” outside the shower area in order to contain the water. However, in an ADA-compliant shower there is no dam or curb so the actual code does not apply. When talking with plumbing inspectors they agreed that a curb was not necessary as long as the water ran to the drain and did not affect any of the other surfaces. That is just “common sense.”

Let’s say you are ready to start a tile project that you were awarded. It has several ADA showers. You know the floors have to have a specific slope to the drain in the shower compartment area. You get there and find that the plumber has the drain too high or the concrete company has not placed the concrete correctly, or both. Now you have an issue with the pitch of the floor to the drain. What do you do?

You look at the tool that GCs, architects, lawyers and judges consult for answers to tile issues: the TCNA Handbook for Ceramic, Glass and Stone Tile Installation. It has many methods for showers that give you all the criteria and information for proven installation methods.

But wait – as of 2014 there was no method for a curbless shower! So we needed to develop one.

This should be easy, right? Let’s just take an existing proven method from the Handbook and expand on it. We’ll remove the curb and waterproof the bath floor area. We will then get a consensus from the Methods and Standards Committee so that we can move this method forward.


The plumbing inspectors will not approve this method for our members without a curb because of the code about the dam. But wait: tile installers have been building curbless showers successfully for quite a while, and inspectors are approving these installations, so let’s push forward. After some changes, the Methods and Standards Committee gives its blessing on this method, so now it has to go to the TCNA Handbook Committee. Here the Handbook Committee – made up of tile installers, manufacturers, consultants, expert witnesses, and people in the know – have the task of making changes and either approving or disapproving the method.

B421CFinally, in the 2015 Handbook, after about three years of work, there are approved methods for curbless showers, and you have information to show your GC how those showers need to be constructed before it’s too late.

It is a long, tedious and sometimes frustrating process to develop a new method in the Handbook. But it is well worth it because of the information it gives the tile installer.

I hope that everyone has a new TCNA Handbook and uses it. It has been developed for you, the tile installer.


kerber_showerJoe Kerber is president/CEO and co-owner with wife Wendi of Kerber Tile, Marble & Stone, Inc., in Shakopee, Mn. Kerber has been in the tile industry since 1969, and began his business in 1973. He has served as president and chairman of the board for the Independent Ceramic Tile Contractors Association (ICTCA), renamed CASTA (Ceramic and Stone Trade Association), and he is a member of the NTCA board, serving on the NTCA Technical Committee and Methods and Standards Committee. Kerber also is regional director for NTCA, which encompasses seven states. Kerber Tile, Marble & Stone, Inc. is a NTCA Five-Star Contractor, and employs CTEF Certified Tile Installers. Kerber was awarded a NTCA Best Practices award at Coverings in April 2015 for his Barrier-Free Shower Installation method, which is included in the 2015 TCNA Handbook for Ceramic, Glass and Stone Tile Installation.

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