Tech Talk – March 2015

TEC-sponsorCustomers warm to electric-heated floors; WiFi thermostats allow remote-control energy efficiency via smartphone or web

By Lesley Goddin

Years ago, if your customer wanted a heated floor, they needed to invest in a complex hydronic system, with copper water-bearing tubes running beneath the floor and a boiler to heat the water and thus the floor.

Over the last few decades, ELECTRIC floor warming systems have been developed by a number of manufacturers. These systems – which utilize heated electrical wire or cable in a loose configuration, a mesh mat, wire snapped into a lightweight backer or uncoupling mat, or even carbon strips embedded in extremely thin PET film – all provide floor warming under tile and stone that is quick, relatively easy to install, and affordable.

1-tech-nuheatSmartphone control via WiFi thermostats

The latest innovation in electric floor warming (or in some cases, full-house heating) systems is WiFi controls, which enable users to control their heating systems, temperature, schedule and energy consumption remotely through their smart phones or other electronic device. Nuheat ( debuted this technology with its Nuheat Signature Programmable WiFi Thermostat. And this January at KBIS during Design & Construction Week, Warmup ( unveiled a WiFi system as well – the 4iE Smart WiFi Thermostat.

Peter Thomson, vice president of sales for Nuheat was at TISE West. He noted that the Signature WiFi app can control up to 16 thermostats on one app, and it’s very zonable. “People are reclaiming their basements with supplemental heat sources,” he said.

Martin Brookes, of NTCA Five Star Contractor Heritage Marble & Tile in Mill Valley, Calif., installs radiant heat in about 60% of Bay Area homes, using the Nuheat system. “We really like the WiFi -enabled programmable thermostat. Living in the Bay Area, the clients are tech savvy and want things they can control with an app from their smart phone.”

2-TECH-warmupAt Warmup, Regis Verliefde, CEO, said the 4iE Smart WiFi Thermostat offers multi-zone and multi-room management as well, in line with Warmup’s goal to provide heating for the whole house. In addition to monitoring the energy consumption, Warmup’s device makes active recommendations to optimize energy use. All this can be directly managed from smartphones and tablets on the MyWarmup portal. (

“We are excited to attend KBIS to show off our latest innovation,” said Verliefde. “Warmup is so much more than luxury in the bathroom. It is a heating solution on par with any other one today, but healthier, more silent and maintenance free.”

3-tech-cmxHeating film; multi-function mats hold cables

Other interesting developments in electric floor warming have taken place over the years. Geo Dream ( encapsulates carbon strips in an extremely thin PET heat film for a system that is zonable, affordable and durable, and heats the house with far infrared waves.

In the last few years, flexible backers to configure wires or cables have emerged, such as RPM mats, which sprang onto the scene in 2006. These mats are studded to accept floor warming cables in any configuration. A new RPM-V1 design has vented studs, that accelerate the drying of the adhesive beneath the mat.

4-tech-schluterLaunched a few years ago is Schluter’s DITRA-HEAT, designed to snap heating cables into a studded uncoupling mat. This mat/membrane provides crack suppression, waterproofing, vapor management and helps to distribute loads as well.

“We just did our first DITRA-HEAT project and liked the flexibility of the system,” said Brookes. “Rather than having to wait for a custom mat, we were able to get the radiant heat we needed off the shelf. “

Italian-made PRODESO HEAT from Progress Profiles features a patented blue studded mat that can be installed as an uncoupling, crack isolating membrane. The heating cables are installed according to the needs of the project. Tiling can begin immediately. The entire Prodeso Heat system is less than 1/4” thick.

5-tech-prodesoCautions and considerations

When working with radiant heating systems, technical service is as important as technology to John Cox, NTCA past president and owner of NTCA Five Star Contactor Cox Tile in San Antonio, Texas.

“The most critical item in my book is customer service. When I call Nuheat, I get answers. They have a staff that has been well trained and educated.

“Selling radiant heating has added additional income to our bottom line and added to the distinction of Cox Tile not being your average tile contractor,” he said. “We have developed a niche as being the expert in our area in Radiant Heating. When architects’ specs say Cox Radiant Heating, we know we have made an impact.”

6-tech-suntouchRicky Cox, of NTCA Five Star Contractors Memphis Tile in Memphis, Tenn., said, “We use Nuheat for the ease of installation, superb customer service, and a long working relationship that has kept us going back for more.  I have installed every system out there and Nuheat blows them all away. The wires are embedded between two layers of fabric that are easily thinset to the substrate.  Other systems are hard to ‘flip and roll’ and hard to figure out.”

Contractors and consultants offer a range of warnings and recommendations when working with electric floor warming.

“Always have the system inspected by a state inspector,” said Joe Kerber, owner of NTCA Five Star Contractor Kerber Tile, Marble & Stone in Shakopee, Minn.

“Always test the cable and sensor for resistance and continuity, before, during and after the installation,” he said.” Be careful when walking on and troweling over the cable so not to crush it or nick it with a trowel. A nick could cause the GFCI to trip when heated. Remember the wires are very fine. The sensor is very fragile so do not step on it.

“There are two types of cable,” Kerber continued. “Most are the double-wire cable that goes out from the box and ends at the end of the cable in the floor area. SunTouch Warm Wire and Nuheat cables are example of these. The other is the single wire that has to return to the original box. The Nuheat mat and Flextherm cables are examples of these. The double-wire cables are easier to install because you don’t have to get the other end back to the box. However, the single wire cables are much easier to repair.”

Jan Hohn of NTCA Five Star Contractor Hohn & Hohn, Inc., in neighboring St. Paul, Minn., added, “I usually prefer to do wires or cables instead of a mat. With the wires, you can really customize the space that you are heating because you can run the wires where you want them, putting them closer together for more heat in a specific area and/or farther apart where there is less foot traffic. Another reason I like the wires is because I float my floors with mud so the wires are buried in the mud bed, which allows for a more consistent floor heat (more mass to heat up, but once it is heated it holds the heat longer and more evenly).”

Hohn cautioned against placing wires or mats under any cabinetry, toilets, or other plumbing fixtures.  “Some systems can be used in showers, but not all, so it is important to determine if the system you want to use can be used in the shower,” she said.

“Recently, it has been recommended to install two floor sensors with one system,” she added. “If the first sensor stops functioning, you can hook up the second sensor without tearing the floor up. It is cheap insurance.”

Rich Goldberg of Avon, Conn.-based Professional Consultants International, LLC (PROCON), noted that “Radiant heat naturally increases cycles of expansion and contraction of a tile assembly, making proper installation of movement joints critical. Butted grout joints with no movement joints in high-end residential stone installations are also a common problem, causing chipping and crushing along stone edges at butted joints.”

Often radiant heat is used to “accelerate” the curing, he said, but this can create problems with premature drying, and expansion stress on the thinset before the bond strengthens. Rapid drying of underlying wood framing in new construction and cement backers can telegraph movement to the tile assembly and result in cracking.

He also warns that cable trays can create dividers in mortar beds that encapsulate the system and crack the mortar, and eventually the tile. They can also prevent mortar adhesion, so PROCON favors systems that “employ the heating cables within a reinforcing mesh so that the system can be properly encapsulated by mortar top and bottom, and the reinforcing distributes any heating/drying/expansion/contraction stress evenly in the mortar bed.



Tech Talk – February 2015

TEC-sponsorAchieving successful natural stone installations


By Tom Plaskota, Technical Support Manager, H.B. Fuller Construction Products

Although advances in manufacturing have expanded the possibilities of man-made tile, natural stone remains highly sought after for both residential and commercial installations. A truly timeless building material – among the world’s oldest – natural stone offers a look that cannot be perfectly emulated by a manufacturing process. By guiding your clients to the right stone and setting it with the most appropriate materials, you will achieve beautiful and durable installations.

Natural stone, as its name suggests, is quarried from the earth. Because of this, it does not offer the perfectly consistent appearance of man-made tiles. Encourage your clients to view several sample tiles from the same lot before making their selection. That way, they can get a sense of how their tile’s appearance may vary.

This diverse material is available in a variety of finishes, and the finish your client selects should be dictated by the project’s environment. Polished stones, for example, are very reflective and may be more sensitive to scratching than other tile types. Honed, flamed/thermal and water-jet finishes are rougher, often obtaining higher slip-resistance ratings than polished finishes. Direct your clients toward higher slip-resistant finishes for floor installations – especially in wet areas.

0215-tech-1If your client’s installation will be on an exterior surface, be sure that the tile they select can withstand freeze/thaw conditions. Specific ASTM tests will verify how well a material may hold up in extreme conditions. Suppliers should be able to provide guidance and technical data to support the recommendations.

Similarly, installations in wet environments – like a shower or pool – require particular attention to stone selection. Many green marbles warp when exposed to water, even from water-based adhesives. These moisture-sensitive stones should not be used in wet environments and should be installed with 100% solid epoxy mortar. Take absorption into account during your selection. The higher the amount of water absorption, the greater the likelihood of damage caused by moisture.

Both performance and aesthetics will determine the setting materials to accompany the natural stone you and your client select. Some natural stones – including light-colored marbles, limestone and onyx – can experience staining or darkening from grey mortars. It is best to specify white mortars for these applications.

0215-tech-2Regardless of color, natural stone requires a minimum of 95% mortar coverage. No voids in the adhesive can exceed 2 square inches and no voids should exist within 2” of tile corners. To achieve consistent coverage, use a larger U-notch or square trowel than you would for similarly-sized ceramic tile. You can also back-butter the natural stone to help ensure 95 to 100% coverage.

Grout is the final ingredient for a successful natural stone application. Particles in sanded grout may scratch limestone, travertine, marble and onyx. If using one of these softer natural stone tiles or polished stone, specify unsanded grout and use grout joints of 1/8” or narrower. Be sure that the grout selected – sanded or unsanded – will not stain the natural stone. Using a grout color similar to that of the natural stone tile will help minimize this risk, as will applying a sealer or grout release prior to grouting. Use the same sealer prior to grouting that you plan to use afterwards.

0215-tech-3To make cleanup easier, consider using a grout bag to grout natural stone installations, particularly with textured tiles. Mix small batches of grout, scoop them into the bag, and squeeze grout from the bag directly into joints. Use a grout float to pack each joint, and then scrape away the excess. If the tile is less textured, use a float to apply the grout directly into the joints.

If you have any questions about the aesthetic or performance compatibility of your tile and setting materials, create a sample board using your client’s natural stone with the mortar and grout you’ve selected. This process will help you determine whether staining is prominent and how the grout and tile look together. Share it with your client to ensure that they will be happy with the final installation.


Tech Talk – January 2015

TEC-sponsorFollow directions, not intuition, for best results with today’s mortars

Lesley beach picBy Lesley Goddin

“Mortar products today are so much better than they were years ago,” said new NTCA president and NTCA Technical Committee chairman James Woelfel, of Artcraft Granite, Marble and Tile Co., from Mesa, Ariz. “That’s why you don’t see as many failures as you ‘should’ see, if you were using mortars from 30 years ago.

“Mortars today are so fantastic,” Woelfel added. “Today, we have flowable/thixotropic and non-sag mortars. They are phenomenal – but they are a double-edged sword,” he said, stressing that if they aren’t used properly, the installation will fail spectacularly.

Woelfel – together with several technical representatives from manufacturers who have collaborated on authoring and editing the mortar section of the NTCA Reference Manual– have some important recommendations for getting the best results from today’s mortars.

Use the right material for the job

An obvious – but oft-ignored recommendation – is to use the proper mortar for the proper tile, Woelfel said. “The more expensive mortar doesn’t cost you more than $.05-$.07 a foot or maybe all the way up to $.15 more a foot,” he explained. “By using the right mortar, you are really buying yourself insurance. Since mortar is the least expensive part of a tile installation, if you are depending on the savings on that mortar to make you a profit, you are going down the wrong road. And if you are improperly using an inexpensive mortar, and building it up, are you really saving money in both material and time?”

Water ratio – follow directions, not intuition!

Second, be sure to mix the mortar the way the manufacturer recommends.

“The mortars being built today are very complex formulations and a lot of ingredients in these formulas require the proper amount of water,” said Leigh Hightower, technical services manager for MAPEI. “Contractors are used to mixing mortars to feel, but today’s mortars have a lot of materials in them that don’t wet out very quickly. If the mortar looks too thick as it is being mixed, and more water is added when it is mixed up, when it does go into solution, it is too thin. Mortars today need to be mixed with a measured amount of water according to instruction and not feel,” he said.

Tom Plaskota, with TEC/H.B. Fuller Construction Products, added, “job site conditions can affect installation and temperature-range limitations are pushed to the limit with the pace of fast track construction these days. This occurs on both the low and high ends of the temperature range, depending on what part of the country you are in and what time of year it is.”

Woelfel cited some of his experiences setting tile in the desert climate of Arizona. He said it’s easy to “overwater thinset in dry climates; there’s more chance to shrink here as it dries. Thin-set mortar sets up faster in Arizona and New Mexico – in fact, in Arizona this June, we set a record for 2% humidity.”

Woelfel said this is a problem because even if one is following strict manufacturer recommendations, those recommendations generally aren’t based on use in extreme conditions. “[Mortar is] tested at 75 degrees and 55% humidity,” Woelfel said. The tendency for mortars to skin over too fast in low-humidity settings is especially crucial when working with large-format, or large thin porcelain tile. Once that happens, there’s no bond.

Woelfel favors the development of more mortars that accommodate the particular conditions contractors encounter around the country – high humidity, or super-low humidity – so contractors have a reasonable amount of open time to set the tile.

“Most people in my area are subcontractors,” Woelfel said. “They are putting tile in as fast as humanly possible, which means they will trowel out 40’ to 50’ of thinset and just drop the tile. They don’t key it in, and it stays on top of the trowel marks. When it’s pulled up, it’s almost clean. There are a lot of failures in Phoenix due to mortar skinning over,” Woelfel said.

Bubbles weaken bonds

Woelfel also cautions contractors to take time with mortars and let them slake. “You need to mix with a low rpm mixer at the proper speed that the manufacturer recommends,” he said. “Otherwise, you can get air bubbles, which makes the mortar set up faster and become weaker. You have to let it rest and coalesce.”

A new name and clearer definition

Large and heavy tile (LHT) mortar, has gone through a transformation – and not just in name only – from the previous “medium-bed” mortar moniker. “Medium-bed” mortar was coined to refer to a MATERIAL – a type of mortar, not a METHOD of tile setting, according to MAPEI’s Hightower. But over time, it became misunderstood and mis-specified in the A&D community as a method of smoothing out imperfections in the substrate in lieu of the proper practice of using a self-leveling underlayment. Contractors got caught in the middle, Hightower said, when they started to be expected to smooth out substrate irregularities with medium-bed mortar, used up to 3/4” in thickness instead of going the proper route of using a self-leveling underlayment. The industry responded to this conundrum by changing the confusing name and limiting the thickness recommended to 1/2” to avoid misuse of this important material. For more information, check out this month’s “By the Book” section in which ProSpec’s Beverly Andrews talks about new parameters for use of LHT mortars or what we formerly called “medium-bed” mortar.

Up-and-coming products for LTPT

LHT mortar segues into mortars many manufacturers are developing specifically for large-unit thin porcelain tiles. These mortars are tied in closely with the standards discussions about large thin porcelain tile (LTPT). As these mortars are in development, contractors are offering feedback on realistic performance criteria. Some manufacturers required 1/64” lippage tolerance, Woelfel said – something unattainable with bigger thin tile. This is where the NTCA Technical Committee, TCNA and other industry entities are putting their heads together to formulate products and methods that will meet the needs of the contractor with excellent performance while the large thin porcelain tile itself is under close scrutiny in terms of performance characteristics and installation recommendations. Stay tuned to TileLetter for ongoing news about LHT mortars for LTPT throughout the year!

Tech Talk – December 2014

TEC-sponsorCold weather tiling

By Lesley Goddin the NTCA Reference Manual

December means cold weather for most of our 50 states, so this month’s Tech Talk literally takes a page out of the NTCA Reference Manual to discuss the particulars and cautions that surround setting tile in cold weather.

The NTCA Reference Manual is an essential industry guide that references real-world, in-the-field situations, in most cases with a cause-cure-prevention format. It also contains letters that can be customized to various parties in the project to legally communicate problems to keep tile contractors harmless in a dispute. This indispensable publication is now available to the entire industry. Visit or click on the “store” link at NTCA’s website, and select books and periodicals to get your copy today.

Following are the recommendations for successful cold weather tiling:


The professional installation of tile in cold weather presents a number of problems. The best results will be obtained when the environment and the products are about room temperature. Each bonding material will require specific precautions.

Tile bonding and grouting materials must not be applied to surfaces that contain frost. Tile must not be installed in areas where the substrate is not maintained above 50° F (10 C) or where the substrate is above 100° F (38 C). Temperature of the substrate shall be 60° F (16 C) and rising for application of epoxy and furan unless otherwise specifically authorized by its manufacturer. Maintain epoxy and furan at a stable temperature between 60° F (16 C) and 90° F (32 C) during the curing period.

Industry specifications do not recommend setting tile below 50° F. If work below that temperature is unavoidable, common sense procedures and precautions should be observed. Be aware that it is the temperature of the tile products, bonding materials and substrate which count – not just the air temperature of the room.

Cold weather slows cement hydration (curing)

It is recognized that cold weather slows the strengthening of cement mortars and grouts and allowances must be made for the resulting risks.

As the temperature drops from 50° F to 35° F, the strengthening of cement slows concurrently, until at 35° F it almost ceases. When these conditions occur, additional time must be allowed for the cement bonding materials to sufficiently harden before traffic is allowed. If the water in fresh cement is allowed to freeze solid, particularly near the surface, the small ice crystals expand, separate the sand and cement, and destroy the strength of the mortar, resulting in a bond failure.

2-TT-1214In cold temperatures, grouting done before the bonding material is strong enough to accept traffic, will cause movement of the tile resulting in irreparable bond failure. When the temperature is below 50° F, grouting should be done immediately after the tile is set or wait at least two to three days. No traffic should be allowed during this period. When continuing a job, special precautions must be taken to keep all traffic off the tile that was set the previous day.

When using blower heaters to protect tile from freezing, caution must be taken to avoid rapidly drying out the tiled area directly in front of the heaters. There is a risk of drying out the air in heated areas preventing proper curing of mortar and grout. It is advisable to damp cure under these conditions.

The use of electric heat is preferable to oil or gas-fired temporary heaters that can cause chalking carbonation and weakening of fresh mortar or grout.

Cover ungrouted surfaces during the initial setting period for protection against drafts and freezing temperatures. Fast-setting mortars, although susceptible to freeze damage, may reduce curing time if the manufacturer’s recommendations are followed.

Epoxies and urethanes

Epoxies require special cold weather precautions. The most likely conditions to occur because of cold temperatures are:

1. A thick stiff mix.

2. Difficult application.

3. A very slow cure and strength gain.

For these reasons, most epoxy products are recommended for use between 70° F and 80° F. Low temperatures can cause epoxies to become so stiff they are unworkable and curing time is extended beyond practical limits. Epoxies should be stored at room temperatures at least 48 hours before mixing. Most epoxy problems result from improper and insufficient mixing.

3-TT-1214Cold weather tiling tips

Nadine Edelstein, winner of a 2010 TileLetter Tile Design Award for the slate strip mosaic in the Maury Island residence outdoor entryway and a 2013 Coverings Installation Design Residential Stone Design Award for the Dragonflower Vine raised-bed garden pathway in Seattle, Wash. Edelstein installed both winning projects during the during the cold northwest winter.

Conditions for the Maury Island project included temperatures in the 30s and wind whipping through the space. The crew bundled up to stay warm and took measures to keep the concrete substrate and curing mortar above 40 degrees. Edelstein said she “used electric blankets over the set tiles layered over with insulating blankets and tarps to keep the heat in. The next day we used the blankets to preheat the areas we intended to set.”

For her 2013 Dragonflower Vine project, elaborate measures included a framed enclosure built over the entire 500+-sq.-ft. garden. “This was covered with heavy-duty tarps that were secured with full five-gallon buckets hanging off the sides!” Edelstein said. “This kept us dry and provided enough ventilation so that we could use a 100,000 BTU propane heater, which kept the chill off of us while we worked. We then employed the same electric blanket technique to help our mortar cure.”

A note of caution from industry expert and ceramic consultant Dave Gobis, CTC – be sure to provide plenty of ventilation – as Edelstein did – when tenting a project. “A tented installation or the cement could kill you from either carbon monoxide or dioxide. Be sure you have plenty of air moving through the enclosure.”

Tech Talk – November 2014

TEC-sponsorA quick thought on labor and large-format tile

hunterBy Lewis Hunter, estimator

I can’t tell you how many times I have been in a conversation with the estimator or project manager of a general contractor (GC) who has wanted me to give them a revised price for 12” × 24” tiles in lieu of 12” × 12” tiles. And when I return the requested price, without fail, they are shocked to see that the price has dramatically increased.  They often argue that the prices of both tiles are relatively the same.  And what’s even more astounding to them, is that I agree.

1-TT-1114It then has to be explained that the increase in cost was due to the labor, increased floor prep, and setting materials. The GC’s estimator further argues that the 12” × 24” piece (2 sq. ft.) of tile is two times the size of the 12” × 12” (1 sq. ft.). This is where it needs to be further explained that with the installation of large-body tiles (typically anything larger than a 12” × 12”) the issue of lippage is more pronounced. Also, the tolerance associated with any sloping in the floor has to be offset. Basically, you have to make the subfloor flatter. The hard-tile estimator now has to account for a thicker mortar. Medium-bed mortar will have to be substituted for thin-set mortar. Consequently medium-bed mortar is more expensive, and the coverage is less than that of thinset. Likewise, labor is increased because the installer now has to massage each piece of tile to make sure it’s level with each adjoining piece. This affects the productivity, which can be reduced by half in some instances. All of these components combined increases the overall price.

2-TT-1114Now, as tile estimators, wouldn’t our lives be so much easier if the end user’s expectations included the above information?


Lewis M. Hunter Jr. was a commercial hard tile estimator for several years in Raleigh, NC. He now serves as the estimating manager for the top residential flooring company in Northern Virginia. Visit or contact him at [email protected] for more information.

Tech Talk – October 2014


Tiling commercial kitchens

tom_plaskota_webBy Tom Plaskota, Technical Support Manager, H.B. Fuller Construction Products

In a typical commercial kitchen, chefs stay on their feet for hours as they hurry from station to station, waiters race to get food out to eager patrons and, inevitably, hot food, drinks and raw ingredients slosh onto the floor – all in a space that must be sanitized frequently to ensure the safety of both employees and customers. Tile installations in commercial kitchens must hold up to these unique demands, because a temporary closure of a restaurant can be costly. Carefully considered product selection and installation strategies will help you create safe, long-lasting and beautiful commercial kitchens.

1-TT-1014Tile selection

For commercial kitchens, look for unglazed tile rated for extra heavy or heavy use. Durable tile with nonslip characteristics will help keep fast-moving restaurant employees on their feet. The tile should also have low porosity and chemical resistance, since these areas will be frequently exposed to moisture and cleaning agents. Select tile that has been tested according to ISO standard 10545-13, which evaluates resistance to chemical interaction. Quarry tile often meets the requirements of commercial kitchen environments.

Substrate preparation

Subfloor requirements for commercial kitchens vary by state. Some states dictate the installation of floor drains, and require that the floor slope toward the drain, going so far as to specify the exact degree of slope. You should familiarize yourself with your state’s codes, and the general contractor or specifier on each commercial kitchen job should clearly communicate whether achieving the required slope is the job of the concrete contractor or the tile installer. If the concrete contractor is responsible for sloping the subfloor, check that they have correctly done so before beginning tile installation.

2-TT-1014If creating the proper slope is your job, use a mortar bed up to 2” in thickness to facilitate accurate slopes or planes, as per the TCNA Handbook. In wet areas, the use of a mortar additive in the mortar bed is recommended. Be sure to create the mortar bed before the application of a waterproofing membrane. The NTCA Reference Manual notes that, “If the proper slope to drains is not already established in the substrate, it should be established prior to the application of the membrane. Failure to slope the membrane results in moisture or water collecting in the mud bed or setting material.”

Following this recommendation is often essential, because many commercial kitchen installations require waterproofing crack-isolation membranes. These membranes protect the substrate from the repeated moisture exposure that occurs in commercial kitchens and help prevent the growth of mold and mildew. They also prevent in-plane cracks in the subfloor from telegraphing through to tile. In commercial kitchen environments, a cracked tile – beyond being a tripping hazard – can foster the growth of bacteria. For these reasons, waterproofing crack-isolation membranes are recommended.

Setting material selection

3-TT-1014Tile can be bonded directly to some waterproofing membranes, including TEC® Hydraflex™ Waterproofing Crack Isolation Membrane. However, for any installation, you must confirm that your mortar and membrane are compatible. Also, ensure that you select a mortar that will hold up to the unique demands of the commercial kitchen environment.

Very busy commercial kitchens – such as those in fast food restaurants – are often exposed to harsh cleaning agents. For these spaces, an epoxy mortar might be the best choice. Epoxy mortars offer high chemical resistance and are also extremely durable and impact resistant.

For all commercial kitchen installations, bond and durability are critical factors. Specific recommended mortars will vary for tile size and type, but for all tile, bond strength is essential. In kitchens, disbonded tiles can be both costly and dangerous. With this in mind, look for a premium polymer-modified mortar specifically formulated for your tile. For example, if the design requires large-format tile, opt for a premium mortar with non-slump and non-slip characteristics to meet the requirements of both the tile and the installation environment.

4-TT-1014The grout must also hold up to heavy commercial use and frequent cleaning. Look for a grout with superior performance – like TEC® AccuColor EFX® Epoxy Special Effects Grout. TEC® AccuColor EFX® was tested for use in food service environments and found to be resistant to food soils and compatible with enzymatic cleaners. Enzymatic cleaners are often used to break down food soils and accumulated grease, and no loss of grout occurred when TEC® AccuColor EFX® was exposed to these products. Its high-temperature formula is approved for surfaces subject to extreme heat or steam cleaning (up to 350°F or 177°C).

A properly-installed commercial kitchen installation, created with thoughtfully-selected products, will continue to be a safe, productive environment. Your understanding of the unique requirements of these spaces will help keep restaurant employees and patrons alike healthy and happy.

For more information about TEC® visit

The TEC® brand is offered by H.B. Fuller Construction Products Inc. – a leading provider of technologically advanced construction materials and solutions to the commercial, industrial and residential construction industry. Headquartered in Aurora, Illinois, the company’s recognized and trusted brands – TEC®, CHAPCO®, Grout Boost®, Foster®, AIM™ and others – are available through an extensive network of distributors and dealers, as well as home improvement retailers. For more information, visit

TEC®, Hydraflex™ and AccuColor EFX® are trademarks of H.B. Fuller Construction Products Inc. 

Tech Talk – September 2014

TEC-sponsorTile not manufactured to industry standards

In the upcoming NTCA Reference Manual, 2014/2015 edition, there is a revised section on the use of tile that is not manufactured to industry standards (p. 128 in the new NTCA Reference Manual; page 124 in the 2013/2014 NTCA Reference Manual if you have a current one on hand.)

This section is pertinent for a range of tile, especially large thin porcelain tile such as Laminam by Crossville®, Plane by StonePeak Ceramics, SlimLite™ by Daltile and the upcoming Thinner by Florida Tile, among others, discussed in the last two TileLetter issues.

The “tile contractor precautions” section is followed in the NTCA Reference Manual, by two letters – one that alerts the architect or general contractor about precautions concerning using tile that does not yet conform to ANSI Standards; the second is a sample letter the contractor can customize to the customer, A&D professional, or distributor that provides some cautions specifically about the use of thin porcelain tile.

For more information about the NTCA Reference Manual, visit online.

1-TT-0914Manufacturers’ standards

American National Standard Specification For Ceramic Tile A137.1 is the only nationally recognized specification for ceramic tile.

Many domestic and foreign manufacturers of tile produce tile products made to the “manufacturer’s own standards.”

In many cases, these standards allow variation in shade, density, consistency of texture, wear resistance, absorption, fractures, squareness, size, thickness, warpage, and mounting that are considerably less stringent than ANSI standards.

Some manufacturers make broad disclaimers in their literature, virtually relieving themselves of responsibility for owner dissatisfaction or for the performance and appearance of their products.

Some disclaimers deny responsibility after the tile is installed. Often, visual inspection prior to installation does not reveal inadequacies of the tile’s performance or possible installation problems.


New to the tile marketplace are families of “thin” porcelain tile products ranging from 3 mm to 7 mm in thickness. Consumer and installer familiarity with thin tiles is increasing in Europe, and such products have already entered the U.S. market. Thin tiles offer new design, environmental, and business opportunities for tile installers, but performance characteristics and installation requirements are different from those of traditional ceramic tiles, especially in flooring applications.

In general, there are four categories of tiles being promoted as “thin” – traditional dust pressed tiles (5-7 mm thick), tiles formed using a “lamina” process (3 mm thick), lamina products reinforced with backing materials, typically with fiberglass (3.5 – 4 mm thick), and lamina tiles sandwiched with fiberglass (6.5 – 7 mm thick).

The first category of thin tiles, which closely resemble traditional ceramic tiles (only thinner), behave similarly to traditional tiles, but are lighter. For flooring applications, they should conform to ANSI A137.1 pressed floor and porcelain tile requirements. They should exceed 250 lbf breaking strength unless otherwise guaranteed by the manufacturer for flooring applications. For wall applications, they should exceed 125 lbf breaking strength, unless otherwise guaranteed.

The second category of thin tiles (non-reinforced lamina tiles) is recommended by manufacturers for wall applications only.

The third and fourth categories of thin tiles (reinforced lamina tiles) have innovative mechanical properties, including impact resistance and deflection capabilities, and manufacturers guarantee such products can be used in both floor and wall applications. However, their inherent thinness, tendency to be large (sometimes up to 3 square meters), and ability to bend require different installation methods and handling. While different from regular tile installation methods, our members should have no difficulty mastering them. Manufacturers usually have thorough guidelines for installation, which should be closely followed.

Until such products are defined by standards, and consistent installation specifications for thin tile are developed, we urge our members and the industry at large to request installation and performance criteria from manufacturers and follow their instructions explicitly for suitable application.

Tile contractor precautions

The tile contractor should carefully review the manufacturer’s warranties and disclaimers to determine the extent of his risk and to take steps to avoid assuming the manufacturer’s and the architect’s responsibilities.

First, the tile contractor should clearly state the manufacturer’s responsibility in the tile contractor’s purchase order to the supplier.

Second, advise the architect or owner, in writing, that the tile he has selected is not manufactured to ANSI Standard Specifications and point out how the manufacturer has been relieved of responsibility by disclaimers and warranty limitations.

Tech Talk – Large thin porcelain tile update, part 2 – August 2014

TEC-sponsorLarge thin porcelain tile update, part 2

Manufacturers share wisdom about successful LTPT installation; contractors counsel caution

By Lesley Goddin

Last month, we looked at the burgeoning new category of large format thin porcelain tile (LTPT) from the contractor’s perspective. This month, we get the low-down from manufacturers of the products themselves – and tips on how to ensure a successful installation, with some words of caution with several more contractors who have had first-hand experience installing the materials.

Training – and experience with the product – cannot be emphasized enough! As an introduction to the product, NTCA has been offering training on LTPT all year at its Tile & Stone Workshop Programs, presented by Gerald Sloan and Michael Whistler at host sites around the country. Sloan and Whistler have attended trainings at various suppliers and setting material manufacturers to get up to speed on what these parties are advising for successful LTPT installation.

1-TechTalk-0814Training reduces fear factor

Crossville, Inc. has been very big on the scene with its Italian-made Laminam by Crossville LTPT – and has been at the forefront of conducting trainings for contractors to familiarize them with the products and the best way to work with them.

“It is not a big learning curve – the material is easy to work with –but without proper tools and training on the job, learning could be not so fun and maybe even expensive,” said Noah Chitty, director of technical services for Crossville.

StonePeak Ceramics, who manufactures Plane 5’ x 10’ LTPT in 6mm thickness, has been conducting twice-monthly, packed-to-the-limit classes at its Tennessee facilities to train installers on using the material. And it also sends a team to distributor locations and invites installers in to witness a live installation for a showroom vignette.

2-TechTalk-0814Todd Ward, vice president of national accounts and director of StonePeak Ceramics’ Plane program says, “Don’t over think it. We are still dealing with porcelain tile – it’s just a bigger size.” Ward points out that 25 years ago, the typical tile size was 8” x 8”, and then it grew to be 12” x 12”, 24” x 24” and larger. With training and familiarity with the product and the new installation methods required for the larger tiles, installers became proficient at working with this new material, he said.

These training opportunities are important, said Ben Szell of European Tile Masters (ETM), a company that has pioneered a number of different tools and pieces of equipment to simplify working with LTPT. They “equip the contractor to stage and choreograph the jobsite before the material are transported to minimize breakage, loss of time, and frustration.”

3-TechTalk-0814Daltile, which supplies fiberglass-backed 1m x 3 m 3.5mm SlimLite™ tile for wall use, has developed a CEU unit for the A&D community that “we are trying to coordinate with our architectural reps, to increase knowledge level and exposure,” said Gregg Link, product director for glazed wall/ceramic mosaics. And Daltile holds clinics at its local Sales Service Centers near projects where SlimLite will be used, to educate the installing contractor on information about the material, including handling, back buttering, and hanging it, so they go into the job feeling confident.

Crossville’s Chitty said that obtaining training can be a real feather in the contractor’s cap, offering “a way to be able to do something their competition can’t.” He recommends selling the tile simply as “large porcelain tile” to the end user, but with the caveat that it “requires qualified labor and specialized equipment if used in full sizes.”

4-TechTalk-0814And confidence is important, because several suppliers have seen skittish contractors overbidding jobs rather than rejecting them – “maybe 200% – 300% more than what a realistic labor rate would be – up to $25/sq. ft. to install,” Link said. “Which is really the same as saying ‘I don’t want to do it.’”

Chitty said that out-of-the-ballpark bids “aren’t good for anyone,” – it’s best to just step away gracefully or send the client to the supplier so they can help.

The right tools make or break the job

ETM’s Szell called LTPT “user-friendly,” since the virtual lack of tension in the product allows contractors to cut and drill very close to the edge. Tools that are specifically designed for this material are essential, Szell said, starting with proper transportation, and suction cup-based equipment to remove LTPT from crates and A-frame racks, cutters, tables and lippage-control systems, as well as trowels designed for full thinset coverage and an edge-finishing machine for beveling, mitering and bullnosing.

Adequate staff is key when handling the tiles, said Jim Whitfield, product manager for Florida Tile. The company will supply fiberglass-reinforced Thinner 1m x 1 m and 1m x 3m tile in 3plus (3.5mm) and 5.5mm thicknesses in 2015.

“The size of these large thin tiles requires at least two people to properly handle the tile from the container to the table for back buttering and also to the installation,” Whitfield said.” This is best accomplished by an aluminum frame with suction cup mounted on it to grab the finished side of the tile.”

And Daltile’s Lynn Mantha, product manager, glazed wall tile, suggested setting up a staging area with a large table ahead of time to handle the material. “You need a stable table for cuts and back buttering,” she said.

5-TechTalk-0814Though LTPTs are usually too large for typical jobsite wet saws, they can be cut by a good straight edge and glass cutter, Whitfield said. “There are also scoring tools on rails that can be mounted right on the face of the tile, making a cut precise and allowing for continuous pressure of the scoring wheel.”

Follow directions!

Florida Tile’s Whitfield emphasized that contractors need to know the specifics of the thin tile they are working with, since LTPTs run the gamut from 3mm to 7mm in thickness, different sizes and with or without fiberglass reinforcement.
“Careful attention should be paid to the manufacturer’s technical manual or installation instructions,” he said, particularly, “areas of use, tools needed, mortar recommendations and detailed installation recommendations.”

Whitfield noted that, “Mortar coverage at all of the edges and corners is critical. The substrates will commonly require a self-leveling underlayment, mortar bed or wall float to meet the industry requirements of substrate variation not to exceed 1/8” in 10’ (3mm in 3m) and 1/16” in 24” (1.5mm in 60 cm) when measured with a straight edge from the high points of the substrate.”

6-TechTalk-0814The thinset is keyed into the substrate and back of the tile then notched with unique trowels like Raimondi’s slant “flow ridge” trowels, which increase the coverage of the mortar between the tile and the properly prepared substrate, he said.

In terms of setting the tiles, Whitfield said that “most mortar manufacturers recommend that thin large format tile floor installations not be walked on within the first 72 hours after installation. A rapid-setting mortar may allow the floor to be opened to light traffic quicker.” Whitfield emphasized that installers and other trades follow these recommendations to a “t.”

Caution counseled by contractors

But some contractors contend that a day or two of training really doesn’t provide all the necessary information to deal with the material successfully – and that there are still a lot of unanswered questions about working with LTPT.

James Woelfel of NTCA Five Star Contractor Artcraft Granite, Marble and Tile, Mesa, Ariz., NTCA 1st vice president and head of the NTCA Technical Committee, asked, “What are the thermal expansion/contraction rates? What are the deflection or torquing rates? How am I – in Phoenix – going to spread 100 sq. ft. of mortar without the mortar skinning over? Mortar manufacturers advised mixing my thinset on the high end of water content. But with that formula, what is the chance that I’ll over-water my mortar to install a 50-sq.-ft. tile 30 feet in the air?”

He continued, noting that the jury is still out about how setting materials can fully support these new LTPTs. “When we discussed the manufacturer’s wish list of standards, including 1/64” in lippage maximum, the question was raised to mortar manufacturers as to what their shrinkage rates for the recommended medium-bed mortar were. Were they more or less than 1/64”? Unfortunately, they didn’t have an answer, nor did they have an answer about how to measure 1/64”. However, that 1/64” was insisted upon so that so the edges will be protected.”

7-TechTalk-0814NTCA Five Star Contractor Nyle Wadford and past NTCA president added, “This is tailor-made for professional contracting firms, especially Five Star contractors. If the product is brought to market the wrong way, failures will increase and the demand will evaporate due to lack of successful installations. We need for this to be successful, but other organizations from around the world are having reservations about installation methods. We just want to see this done correctly.”

Martin Howard of NTCA Five Star Contractor David Allen Company and NTCA 2nd vice president feels more product development is needed on the part of the manufacturers before the product is fully ready for market. “In my opinion the manufacturers have only completed half of the product development process,” Howard said. “Until they have developed a consistently reliable and reproducible system of installation with defined criteria, this product is not market-ready and should not be sold to the unsuspecting public without some warning of the potential risks.”


As stated in part I of our story in the July issue of TileLetter, standards for LTPT are currently under development. Florida’s Whitfield makes the point that it’s not new in our industry to have products in use in the field as standards are developing, as is the current case with premixed grouts, uncoupling membranes, and sealers.

But NTCA’s executive director Bart Bettiga emphasizes that though standards don’t yet exist, there IS some consensus about the materials that is critical for contractors to heed for their own protection.

“Most manufacturers haven’t produced test results that lend confidence to install for any material thinner than 5.5mm for the floor,” he said. “LTPT is groundbreaking technology. We don’t want to get careless and start using this material in a risky way, or in thicknesses less than 5.5mm on the floor until more testing is done and a new consensus is achieved. The tile contractor accepts all the liability in a LTPT project, so we want to be sure contractors are installing tested and approved materials using tested and approved methods and recommendations. “

In fact, a “Thin Tile Position Statement” has been issued by the National Tile Contractors Association (NTCA), Tile Contractors Association of America (TCAA), International Masonry Institute (IMI) and International Union of Bricklayers and Allied Craftworkers (IUBAC). In it, all these organizations “recommend that tile contractors not install thin porcelain tile panels in any thickness less than 5.5 mm for floor installations until standards are developed and consensus is reached that thinner materials may be used on floors. It is our assertion that installations of thin porcelain tiles that are no less than 5.5 mm thick may be successfully accomplished in properly-prepared floor applications with the proper care and processes.

“The tile contractor should be aware that significant training and education are required to successfully install these products and that an investment in tools and equipment is necessary,” the statement continues. “The manufacturer of the tile and setting materials recommendations should be secured in writing prior to installation and the contractor should follow these instructions carefully or potentially be exposed to increased risk and liability.”

Obtaining training, taking care with installations and following manufacturer recommendations set the stage for the greatest success with these new products. And that’s important, because there are many factors that make LTPT an attractive product with a great future: thinner tile; fewer raw materials; lower temperatures and shorter length of time in the kiln vs. traditional porcelains and much less weight to ship, Whitfield said. Plus, “owners like the fewer grout joints, ease of maintenance, and most important the look and thin profile of these tiles,” he said.

Stay tuned for part III later in the year, which explores the topic of LTPT from the setting-material manufacturer viewpoint.

Tech Talk – July 2014


Summertime exterior installations from start to finish

tom_plaskota_webBy Tom Plaskota, Technical Support Manager, H.B. Fuller Construction Products

The arrival of summer often inspires (or requires) homeowners and building owners to beautify their outdoor spaces. A new tile installation can freshen up a pool area, breathe life into a patio or update a building’s façade. While the summer sunshine sparks imaginations, turning your clients’ exterior visions into reality requires special expertise.

Whether remodeling an existing exterior tile installation or starting from scratch, substrate preparation is key. Concrete is the ideal substrate for exterior floor installations, while other firm substrates, including backer board or concrete block walls, can be used for wall installations. When setting tile on existing concrete, make sure you address any liquid-membrane curing compound residues. These products can prevent proper bonding of mortar to the concrete surface, so should be removed through scarification or covered with an appropriate primer.

Laitance – a thin layer of hardened, yet weak, cement – can also affect the substrate’s bonding potential. If laitance exists, the concrete’s surface layer may appear strong and stable, but actually risks causing bond failure. Laitance can be identified by scraping the concrete with a razor or knife. If the concrete scratches or powders, laitance may exist. Formal testing can then be undertaken by measuring the tensile strength of the concrete surface with specialized equipment. The remedy for a weak layer of laitance is removal, which is often done by sandblasting.

1-TT-0714Prepare substrate for a solid foundation

After these preliminary steps, any variation in the substrate should be corrected. Use an appropriate patching compound to flatten the substrate surface. Exterior floors, decks or patios should be sloped to allow for drainage. Concrete on grade should also have a gravel bed or other means of drainage below the slab. Drainage is particularly important for installations subject to freeze/thaw cycling, snow and ice accumulation and/or where snow melting chemicals are used as these conditions can cause degradation over time.

Exterior installations may be subject to changes in temperature and humidity level. This cycle can put mechanical stress on the substrate – which can cause cracking. Waterproofing and crack isolation membranes can help isolate substrate cracks and keep in-plane cracks in the subfloor from telegraphing to the tile. Their waterproofing characteristics can also prevent moisture changes from affecting the substrate.

Combining the right tile with a carefully-prepared substrate helps make exterior installations last. For outdoor floor installations, unglazed tile with its nonslip characteristics is often ideal. All tile used in exterior application should have low porosity. According to industry standards, tile with a porosity of greater than 5% should never be used in exterior applications.


Be mindful of moisture

When your substrate is prepared, your tile is selected, and you’re ready to begin tiling, make sure the installation won’t suffer from excessive porosity in the substrate. Before you begin mortaring, splash water on the concrete. If the water disappears in a few seconds, the substrate is very porous. One way to remedy this problem is to dampen the substrate and allow the surface to dry. Mortar should be applied after the surface dries, but before the moisture below the surface is lost. This will prevent the transfer of moisture from the mortar and result in a proper cure and well-bonded tile. A primer may also minimize the pull of moisture from the mortar into the substrate, ensuring proper curing and bonding.

Moisture can be lost to the atmosphere when the installation is conducted or allowed to cure in direct sunlight on hot, dry days. Excessive heat can prevent fresh mortar from curing properly and developing the necessary strength for long-term installation. On hot days, shield the installation from direct sunlight by tenting. Also, avoid storing unused mortar in direct sunlight.

3-TT-0714Create consistent coverage

To make all of these precautions worthwhile and keep your installation from slumping, sagging or slipping, be sure to achieve proper coverage with a polymer-modified thin-set mortar appropriate for exterior installations. Outdoor installations require 95% coverage – and this requirement increases to 100% with natural stone. Substrate variation, bonding material, trowel selection, and troweling technique are critical factors to consider when trying to achieve proper coverage.

For outdoor environments, use a polymer-modified grout with low water absorption. Consider the use of a grout additive, which can help provide a grout that is stronger, denser, more resistant to water penetration and more flexible. Sealants and caulks can also prevent external elements from penetrating your installation – without changing its appearance.

When working on exterior installations in the hot summer months, you and your crew should take proper precautions not only with the installation, but also with your own health and safety. Make sure you stay hydrated and take breaks as needed. With a healthy crew, a properly-prepared substrate, carefully-selected products and the right installation techniques, you’ll help your clients achieve the outdoor spaces they imagine.

The TEC® brand is offered by H.B. Fuller Construction Products Inc. – a leading provider of technologically advanced construction materials and solutions to the commercial, industrial and residential construction industry. Headquartered in Aurora, Illinois, the company’s recognized and trusted brands – TEC®, CHAPCO®, Grout Boost®, Foster®, AIM™ and others – are available through an extensive network of distributors and dealers, as well as home improvement retailers. For more information, visit

Tech Talk – June 2014

TEC-sponsorANSI requirements for porcelain tile shears are too low

NTCA Recognized Consultant recommends minimum of  300 psi shear rating

1-TT_0614By Tom D. Lynch, CSI

Nearly every ceramic tile floor installation failure that I inspect involves porcelain tile. Perhaps that is due to the popularity of these types of tiles, but a very disturbing trend has emerged that I think warrants discussion. In more cases than not, adequate mortar coverage has been achieved by installers, yet tiles shear off in alarming numbers from the lateral stress that has been applied. Tiles do not let loose from substrates without some sort of stress being applied, usually in the form of a crack appearing somewhere, but I think the extent of these failures can be reduced dramatically.

We all agree that it takes a polymer-modified mortar to hold porcelain tiles in place. The mechanical bond achieved with non-modified mortars is just not enough. The adhesive bond that polymers provide must be added. With this in mind, ANSI insists that a minimum A118.4 porcelain tile shear of 200 pounds per square inch (psi) with a polymer-modified mortar must be obtained for installations of impervious porcelain tile. Do you realize that a good high-quality, non-modified mortar will achieve close to 195 psi on a porcelain shear test? Add about a thimble full of polymer and these mortars could easily hit 200 psi. NOT ENOUGH, I say. For the betterment of the industry, porcelain tile minimum shears must be increased.

2-TT-0614Let me give you another reason why they must be increased. The A118.4 porcelain tile shear test is performed by bonding 2” x 2” porcelain tiles together with a 1/8” offset. After curing, the tiles are sheared by applying lateral pressure and measuring the amount of pounds per square inch that it takes for failure to occur. It must be noted that the coverage of the bonding mortar is basically 100%, yet ANSI A108.5 paragraph 3.3.2 allows only 80% coverage for interior installations of tile (other than wet areas where 95% is required).

In essence, 80% coverage of a 200 psi mortar will only accomplish 160 psi of strength, which is 40 psi short of the minimum requirements for porcelain tiles. At the 95% allowable coverage for interior wet areas and all exterior installations, only 190 psi is obtained. Raising the minimum requirements for the A118.4 porcelain shear is a must, but how much is enough?

Engineering cement/polymer chemistry for thin-set mortars is not as simple as baking a cake. There is a fine point where adding too much volume of polymers with high-flex qualities will greatly increase the adhesive bond but unfortunately will reduce shear strengths. What we do not want is a thin-set modified polymer that will bond to nearly any substrate but cannot hit minimum shear strengths.

3-TT-0614Shoot for 300 psi minimum shear rating

In my opinion, the key is to engineer a polymer modified thin-set that will obtain at least a 300 psi shear rating for porcelain tile. I chose this number for a couple of reasons. First, it greatly increases the current requirement and allows for 240 psi at 80% coverage and secondly it coincides nicely with the newer ANSI A118.15 specification that calls for a minimum 400 psi porcelain shear for many applications.

Porcelain shears of 500-600 psi and more are not unheard of in the industry, but at some point costs must be considered along with performance. I know that many people will complain that the additional cost of a higher-performing A118.4 or an A118.15 mortar for porcelain tiles will be too inflationary, but I say “no way!” Porcelain tiles will likely continue to dominate the industry as the floor tiles of choice, but it is in all of our best interests to lower the number and the extent of porcelain tile failures. A few cents per square foot of additional costs to insist on a better-performing mortar should not be a deal breaker on any project.

By the way, I do not advocate increasing the ANSI A108.5 coverage minimums. Tile installers are, after all, human and insisting on 100% coverage is totally unrealistic.


Tom D. Lynch is an experienced and accomplished technical consultant to the ceramic and stone tile industry. Honored to be one of the first Recognized Industry Consultants by the NTCA, Lynch now has 52 years of experience to draw from. He can be reached at 181 Sunnyside Park Road, Jefferson, NC 28640 or by phone at 336-877-6951. Website is Email at: [email protected]

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