Tech Tip Tuesday: Q & A With NTCA Training Director Mark Heinlein – 10/24/2017

Member Question:

We are encountering issues with a wall tile installation. I am trying to find out what the wall assembly should consist of in regards to metal studs, horizontal reinforcement, etc.   Your response would be greatly appreciated.

Mark’s Response:

Thank you for contacting the National Tile Contractors Association.

Please refer to the Tile Council of North America (TCNA) Handbook Method W243-17 for the details and best practices for the wall installation you are dealing with.  This method requires metal studs to be well braced; 20 gauge (0.033”) or heavier; minimum depth 3-5/8” for commercial applications.  The gypsum board must meet ASTM C1396/C1396M with a minimum of 1/2” thickness for single layer applications and must be installed per GA-216.  Maximum allowable variation of the substrate (for the installation of 12”x12” tile) is to not exceed 1/4” in 10’ (feet) from the required plane with no more than 1/16” variation in 12” when measured from the high points in the surface.  Additionally, details for movement and expansion must be met as required by TCNA Handbook method EJ-171.

I have attached a photo of the section of the 2017 TCNA Handbook that discusses “Equivalent Gauge” Steel Framing in case that material has been used on this project.

In addition, the NTCA Reference Manual includes an excellent discussion of EQ Gauge steel framing.  It states, in part, that the wall framing should meet a deflection limit of L/360 for the rated load based on the properties of the stud alone.  It further states that it is the responsibility of the design professional and framing contractor to ensure that wall assemblies for tile and stone finishes are designed and assembled to meet performance requirements, and all manufacturers of EQ studs will have the technical data needed for design and confirmation of performance requirements.

I am glad to learn you will be joining the NTCA.  As a member, you will find many benefits including tremendous networking and educational opportunities with many likeminded tile industry professionals looking to improve their level of performance and education based on tile industry standards. Other benefits include receiving a copy of the TCNA Handbook and the NTCA Reference Manual each year with your membership renewal.  I look forward to discussing membership with you next week when you call back.  In the meantime, please visit for more information.  You can view additional member benefits at this link:  you can also join by clicking on the “Join Now” link found anywhere on our website.

I hope this helps!

Mark Heinlein

NTCA Training Director

Tech Tip Tuesday: Q & A With NTCA Training Director Mark Heinlein

Member Question:

I have a job where we installed a porcelain tile. It is 8” x 15” and the side walls are fine but the wet walls are not good.  The worst part is they have that system of lighting where it is shining down directly from above so it shows all discrepancies and shadows. Is there anything in the industry standards that allows for a tolerance for a little lippage?

Mark’s Response:

Thank you for contacting the National Tile Contractors Association.

The standard for lippage is found in ANSI A108.02 Section 4 (copy attached) and is echoed in the TCNA Handbook.  Generally speaking, 1/32” in addition to the allowable warpage of a tile manufactured in accordance with ANSI A137.1 is the allowable lippage for wall mount mosaics with a grout joint width of 1/16 – 1/8”.

I understand these strip mosaics can be difficult and time consuming to install.  You are correct that substrate flatness is the place to start to help ensure the installed lippage is within tolerance.

The NTCA Reference Manual has an excellent section describing Wash Wall Lighting and how to avoid problems that can be associated with it.  If you have your Reference Manual at hand, it will provide some good reading on this topic.

The 2017 TCNA Handbook contains a section on Visual Inspection of Finished Tilework.  I don’t have my book close at hand but it is in the first 30-40 pages.  It may help your situation that visual inspection of wall installations is performed at 36” from the tilework.  Please take a look at that section in the Handbook and see if it can work for you in this case.

Please let me know if I can help with any further questions you might have after you are able to review the documents I listed above.

I hope this helps!

Mark Heinlein

NTCA Training Director

Tech Tip Tuesday: Q & A With NTCA Training Director Mark Heinlein

Member Question:

Is there a reference in the NTCA Reference Manual or other publication pertaining to use of waste or fall off that is standard in tile installation?

Mark’s Response:

Thank you for contacting the National Tile Contractors Association.

I am not aware of a written recommendation for calculating waste percentages for tile estimates.

My recommendation is:

  • Straight lay / Basic installations:  5% + sufficient attic stock
  • Diagonal / Slightly more complex installations:  8 – 10% + sufficient attic stock
  • Complex designs or patterns:  12 – 15% + sufficient attic stock

The size of the installation will make a difference.  Very large, well planned areas may not generate much waste.

Installations involving hallways and many adjoining rooms may require calculating additional waste.

Careful review of the plans, designs and details is necessary for each job.

I hope this helps.

Mark Heinlein

NTCA Training Director



Do you have any guidelines on how to install porcelain tile according to ANSI Guidelines you could send me, please?

Mark’s Reply:

Thank you for contacting the National Tile Contractors Association.

Below, I have listed for you the primary tile industry standards, methods and guidelines for the installation of porcelain tile.

  • American National Standards Institute (ANSI) A108 and A118 – American National Specification for the Installation of Ceramic Tile – Material and Installation Standards
  • ANSI A137.1 – American National Standard Specifications for Ceramic Tile
  • Tile Council of North America (TCNA) Handbook for Ceramic, Glass, and Stone Tile Installation

These standards and guidelines are extensive in that they cover many types of installations using tried and true best practices, methods, techniques and materials recommended for a variety of structures and substructures.  I am not able to send these to you, but they are available for purchase at this link:

If you are a tile contractor, these standards will be your guide for all of your tile installations.  I encourage you to purchase them and become familiar with them and use them in your installations.  In addition, I encourage you to explore membership in the National Tile Contractors Association.  More information can be found here:

If you are an owner considering accomplishing a tile installation, I strongly encourage you to interview and hire a qualified, certified contractor and installer who owns, understands and uses the tile industry standards I listed above.  Please research the below links to locate an NTCA Member contractor and CTEF Certified Tile Installer near you.

Why Hire an NTCA Contractor:

Locate an NTCA Contractor:

Why Hire a CTEF Certified Tile Installer:

Locate a CTEF Certified Tile Installer:

I hope this helps.

Mark Heinlein,

NTCA Training Director

Tech Tip Tuesday: Q & A With NTCA Training Director Mark Heinlein

Member Question:

I need installation guidance to install a ceramic or porcelain tile over a concrete slab/sidewalk. This will be outside of a church and it is currently a concrete floor and curb. What would you recommend we use at the edge and expansion joints?

Mark’s Response:

There is a lot to consider before tiling a project like this one.  Since you may not have yet received your 2017 TCNA Handbook, I have attached a couple of photos of two methods (F101 and F102) that may be most applicable to your installation.

F101 describes an on ground concrete substrate with proper drainage below the slab, bonded mortar bed, ceramic tile and optional waterproofing / crack isolation membrane.

F102 describes an on ground concrete substrate with proper drainage below the slab, cementitious bond coat and optional waterproofing / crack isolation membrane.

Both of these methods will require proper drainage beneath the slab and drainage for surface water runoff from the finished surface and further drainage into the landscaping.  If the slab abuts a permanent structure, you will want to be certain that the drainage is slope away from the structure – the general rule would be 1/4” vertical slope per 12” of horizontal run.  Besides methods F101 and F102, there may be other methods and materials that will help with system drainage if that is an issue.

Prior to proceeding you will need to determine if this is a well cured slab and whether it is dimensionally stable and free of cracks, films, curing compounds, sealers, etc. and whether it’s surface has been at least steel troweled with a fine broom finish suitable for mortar to bond to it.  The flatness requirements of 1/4” per 10’ must be met for application of an F101 Thick Mortar Bed or for F102 direct bonding of tiles less than 15” on one side.  For direct bonding of tiles with one side 15” or longer the slab must meet the 1/8” per 10’ flatness requirement before the tile (or membrane) is to be set.

You will see that both of these methods list a membrane as optional.  Inclusion of a membrane will help with waterproofing above the substrate and a degree of crack isolation from minor existing or future in-plane cracks.  If the slab is abutted to a structure, I suggest looking for a way to flash the membrane up the side of the structure, potentially beneath the siding (if any).  The “Membrane Options” section of the method lists the specific membrane requirements and also points to Handbook methods F125-Partial / F125 – Full for crack isolation.

Some membrane manufacturers state that their membranes will be able to span certain types of joints if installed per their instructions and as part of a full system warranty (use of one manufacturer’s mortar, grout, membrane, sealant, etc.).  Installation of a membrane will help with waterproofing, some system drainage, and to protect against efflorescence from the substrate.

The “Materials” section defines the specifications for the tile and setting materials to be used in this method.

You are correct that this installation will need Movement Accommodation Joints.  TCNA Handbook Method EJ-171 provides the details.  As a minimum, those joints should be placed around the perimeter and at every change in plane or where the tile meets a different material.  Expansion joints in the concrete slab must be honored upward through the finished surface of the tile.  Expansion, Isolation, Construction, Contraction and other joints must be addressed.  For an exterior installation, joints throughout the tile field are required every 8’ – 12’ depending on materials and environmental conditions.  Appropriate joint width must also be determined based on environmental conditions the installation is expected to be subject to.  Sealants complying with ASTM C920 with an appropriate designation for this type of installation will be required for the soft joints.  As this is a traffic area, a sealant with a shore A hardness rating of 25 or greater should be considered.  Conversely, a manufactured joint may be available to use.  As we discussed in our workshop, it is the responsibility of the design professional or engineer to determine the location / placement / width / construction of these joints.  Method EJ-171 provides details on constituting these joints – but is too much information for me to forward in this e-mail.

Since this is an exterior installation with some potential of freeze/thaw cycling, expect there to be some system / component degradation over time that may require routine maintenance.

You will want to finish and protect the exposed edges of the tile with a commercially rated, durable metal trim such as brass or stainless steel. Bullnose, or tiles that have been custom bullnosed for the project may also work well depending on the expected use and conditions.

I hope this helps point you in the right direction.  You should have your new 2017 TCNA Handbook soon so you can refer to these methods and all of the other great guidance it contains.

Mark Heinlein

NTCA Training Director


Consumer Question:

The concern that I have at this time is the installation of soft joints at the change of plane in the corners of the tub surround. The product is a 12″ x 24″ marble.












The tile pieces most definitely butt up against one another and it is my belief that the tile installer is going to place a bead of caulk up along the exposed surface of the two.
I am concerned this is not a soft joint to allow for movement of the tiles, but rather a bead of caulk to hide the connection (more aesthetic than functional).  Would this be a concern for you? If so, what types of issues may I have in the future if there is no soft joint?


Mark’s Reply:

Thank you for contacting the National Tile Contractors Association!

The Tile Council of North America Handbook and ANSI Standards require functioning open movement joints at changes in plane.  If those joints are tight butted there will be no room for them to properly function to absorb the natural flexing, movement, expansion and contraction that is inherent in all construction.  Without being there in person I am not able to comment definitively however, the joints in your photos do appear to be either tight-butted or have too tight of a joint.

Movement joints at changes in plane are required and are functional and should be filled with a flexible sealant appropriate for the area it is being used.  For a wet environment such as a shower, an ASTM C920 sealant such as a 100% silicone or urethane can be used. These sealants are manufactured to match as closely as possible the grout color.

Before applying the sealant in your marble installation, a test sample should be done along the edge of a scrap piece of marble.  Some colors of sealants have colorants that may absorb into the soft stone and may cause staining that can be visible along the edge of the tile. This is a common pre-installation test that should be done with all marble installations.  A phone call to the technical department of the sealant manufacturer may help determine which of their colors are best suited for soft stone.

The best way to find an NTCA Recognized Consultant in your area is to review our list at this link: These are highly regarded consultants that may travel regionally or nationally.  Feel free to let them know about the conversations we have been having.

I hope this helps.

Mark Heinlein, NTCA Training Director


Contractor Question:

I am thinking about putting a heating TapeMat in the floor of my bathroom.  The manufacturer’s literature suggests a modified thin-set mortar.  I am using a large format tile (12” x 24”).  I am placing the tile on a 3/4 inch plywood subfloor with a 1/4 inch Hardy board backer.  The floor is supported by 2”x12” floor joists spaced at 16” on center.  The bathroom is L shaped and is  8’x4’ with a 3’ L.  The 8’ wall is an exterior wall. Would an unmodified mortar work as well? Is it even advisable to use a modified mortar with a large format tile?

Mark’s Reply:

Thanks for the info.

Assuming ceramic/porcelain tile is being installed, the industry recognized method found in TCNA Handbook is RH135-16.  The method describes the details for an electric radiant heat system encapsulated in mortar over backer board on a plywood subfloor with joists 16” on center, which is the installation you have described.

It sounds like you are not installing a waterproofing membrane in the system.  In that case, the required thinset mortar for the cementitious bond coat is an ANSI A118.15.  In other words, an Improved Modified Dry-Set Cement Mortar is required.

The mortar you select should have the words “Meets ANSI A118.15” stamped on the package.  Be certain to carefully follow the mortar manufacturer’s instructions for the proper amount of water, mixing instructions, slaking time, open time, etc.

You asked whether it is advisable to use a modified mortar with a large format tile.  It is.  In fact, many manufacturers are now producing highly modified mortars specifically designed for Large and Heavy Tile.  You may find mortars labeled as “LHT” for this reason.  These mortars have specific properties to support the installation of large and heavy tiles on floors and walls.  Some allow for a thicker bond coat.  This is the type of mortar I would look for when installing an electrical heating tape mat system in the bond coat layer.

If you are using a membrane in the system, it may be advisable to use a less highly modified mortar (such as an A118.4) or even an unmodified thinset mortar (A118.1).  Check with the manufacturer of the membrane for their specific mortar recommendation.

Please make certain the surface of your plywood subfloor is flat to meet the industry standard tolerance of 1/8” in 10’ as required by ANSI A108 before you install the backer board.  This will ensure you have a flat finished tile surface on your large format tile installation.  Use a rapid setting patch material to fill low spots and a belt sander on the high spots of the plywood.  Do not use more or less thinset to help you flatten your installation while you set tile.  Doing so will prove problematic for you and your installation.

Membership in the National Tile Contractors Association is a valuable resource for any professional tile contractor or any contractor who installs tile.  NTCA is committed to improving installations and performance of contractors throughout the tile industry.  Our primary mission is training based on the tile industry standards I have described above.  Every installer should own and be familiar with the standards, methods and details that guide the tile industry.  I would be happy to discuss with you and your tile installation contractors the many benefits of membership in NTCA.  Please feel free to contact me, or Jim Olson at for more information.  Also please visit our website at

The Ceramic Tile Education Foundation (CTEF) supports education and training in the tile industry.  The Certified Tile Installer (CTI) program is a highly sought after certification for tile installers who wish to achieve a higher level of professionalism and recognition in the tile industry.  Please visit the CTEF website at to locate a Certified Tile Installer or contact Kevin Insalato at for more information on how a contractor can become a CTI.

I hope this helps.

Mark Heinlein, NTCA Training Director


Tech Tip Tuesday: Q & A With NTCA Training Director Mark Heinlein

Consumer Question:

Hi! Recently, our new tile floor began cracking. Our builder took up the damaged areas, fixed deflection, and replaced damaged tiles. Now, more tiles in other areas are cracking. Is it standard practice to continue piecing the floor together or is it better to rip out the whole floor?


Thank you for contacting the National Tile Contractors Association.

It is not at all standard to have to make repairs like this to a new tile installation.

What is standard is to ensure the structure including the subfloor and substrates that will support the tile installation are properly engineered, designed and constructed before the tile installation begins. There are standard requirements to meet tolerances for deflection.  When deflection and substructure requirements are met, tile installations can be designed and installed using additional tile industry standards, methods, best practices and techniques.

The primary tile industry standards are found in these publications:
American National Standards Institute Specifications for the Installation of Ceramic Tile (ANSI A108)
American National Standards Institute Material Specifications (ANSI A118)
Tile Council of North America (TCNA) Handbook
In addition to deflection, there may be other factors that could be leading to this failure in your tile system.  Tile installations are complex.  Every aspect of the installation must be performed according to industry standards and material manufacturer instructions to ensure a long lasting successful installation.

Ask your tile installer which standards and methods from the above listed publications they followed to install your project.

Is your tile contractor a Ceramic Tile Education Foundation Certified Tile Installer (CTI)?  CTIs are recognized by the tile industry to have the necessary knowledge of these industry standards along with the proven skills and experience to construct long lasting tile installations.  You can search the list of CTIs in your area at this link:

Is your installer an NTCA member or an NTCA 5 Star Contractor?  NTCA member contractors can be located here:  Membership in the NTCA is a valuable resource for any professional tile contractor or any contractor who installs tile.  NTCA is committed to improving installations and performance of contractors throughout the tile industry.  Our primary mission is training based on the tile industry standards I described above.

NTCA 5 Star Contractors that employe CTIs can be located at this link:

Every installer should own and be familiar with the standards, methods and details that guide the tile industry.  If your contractor is not familiar with the standards or if they are not an NTCA member or Certified Tile Installer, I would be happy to discuss with them the importance of these programs.  Please feel free to have them contact me, or Jim Olson at for more information.

The NTCA and the entire American tile industry want you to have a beautiful and functional and safe installation that will stand the test of time and that will make you happy and comfortable and proud to own. Employing Certified Tile Installers and NTCA member contractors is a step in the right direction to ensure a successful tile installation based on tile industry standards.

I hope this helps.


CTEF Regional Evaluators Expand Certified Tile Installer (CTI) Hands-on Testing Program

The Ceramic Tile Education Foundation (CTEF) has developed a Regional Evaluators (RE) program to expand the Certified Tile Installer (CTI) Program hands-on testing. The program is led by Regional Evaluator Coordinator Kevin Insalato who reports to Scott Carothers, Director of Training and Education for CTEF.

“It is critical for the future of the tile industry that homeowners, architects, designers and commercial business owners have the option of qualified labor for their tile installation projects so the installations not only look beautiful, but also perform consistently over time,” says Carothers. “The CTI program was developed to provide that level of assurance to those seeking professional tile installers. With the Regional Evaluator program, CTEF can significantly grow the number of CTIs and the level of tile installation competence available across the United States.”

What is the Regional Evaluator Program?

Regional Evaluators are themselves Certified Tile Installers who take additional training to evaluate the hands-on portion of the Certified Tile Installer Program test. They must know how to set up the testing modules, conduct the hands-on test, score the 100-point evaluation, and assist installers in furthering their understanding of the proper installation of ceramic tile.

They are regionally based and able to organize and conduct hands-on testing within their region which greatly expands the reach of the CTI program. This also means that installers no longer need wait until classes reach 10 or more students before they are able to take the hands-on portion of the exam and achieve industry-recognized certification and validation of their skills and knowledge.

Kevin Insalato of California Flooring in the Chicago area, serves as Regional Evaluator Coordinator for the program and has kicked it off with the following sixteen Regional Evaluators:

Joe Kerber, CTI # 217, Kerber Tile Marble & Stone – Shakopee, MN
Robb Roderick, CTI # 727, NTCA Trainer – West Coast USA
Mike Corona, CTI # 923, Corona Marble & Tile, Woodbine, MD
Shon Parker, CTI #999, Hawthorne Tile, Portland, OR
Dave Rogers CTI # 1029, Welch Tile – Kent City, MI
Rafael Lopez, CTI # 1100, California Flooring – Manteno, IL
Mark Heinlein, CTI # 1112, NTCA Trainer – East Coast USA
Tom Cravillion, CTI # 1116, Cravillion Tile & Stone – Plymouth, WI
Matt Newbold, CTI # 1118, Elite Tile Setters – Lehi, UT
Triniti Vigil, CTI # 1144, J&R Tile – San Antonio, TX
Brad Denny, CTI # 1190, Nichols Tile & Terrazzo – Joelton, TN
Dan Hecox, CTI # 1215, Hecox Construction – York, NE
Jason McDaniel, CTI #1273, Stoneman Construction, Stafford, OR
Todd Kozey, CTI # 1285, Complete Contracting Services – Fraser, MI
Ed Siebern, CTI # 1289, Mourelatos Tile Pro, Tucson, AZ
John Mourelatos, CTI # 1290, Mourelatos Tile Pro, Tucson, AZ
“With the Regional Evaluator Program, we can now take the CTI hands-on test to installers, retailers, and tile contractors around the country increasing the number of qualified installers available to the marketplace,” says Insalato. “That’s exciting!”

The program will initially utilize sixteen REs and eventually include a minimum of 50 Regional Evaluators. For more information about the Regional Evaluator program, visit

What is the Certified Tile Installer Program?

The CTI designation identifies the professional installer who has reached a level of proficiency to independently and consistently produce a sound tile installation that displays good workmanship. Certification is the validation of the skills and knowledge of the men and women who presently are installing tile successfully in the United States.

To qualify for the CTI Program, installers must have at least two years of experience as the lead installer setting ceramic tile on a full-time basis. This means having full responsibility for substrate prep, layout, coordinating with other trades along with properly installing underlayment, tile, grout and sealant materials.

The CTI test is a two-part examination consisting of:

A written test which is an open-book, 155 question, multiple-choice exam that can be taken online at home or the office as the installer’s schedule allows.
A hands-on test which is monitored and assessed by Regional Evaluators all across the United States. In it, installers must demonstrate their ability to execute a complex layout and proper installation of vapor retarder membrane, backer board, tile (walls and floors), cementitious grout, and flexible sealant (caulk). For each installation material, the applicant is scored on the various aspects of workmanship relevant to producing an installation that will endure use and satisfy the discriminating client.
The CTI Program: Recognized by the Tile Industry

The Ceramic Tile Education Foundation (CTEF) which sponsors the CTI program is supported by all segments of the ceramic tile industry. CTEF is headquartered in Pendleton, South Carolina, near Clemson University and in close proximity to the offices of the Tile Council of North America (TCNA).

The Ceramic Tile Education Foundation (CTEF) provides education and installer certification for professionals working in the ceramic tile and stone industry. The CTEF Certified Tile Installer (CTI) program is the only third-party assessment of installer skill and knowledge which is recognized by the tile industry.

To register for the CTI tests, please visit, select the test date and location of your choice, and make your payment through the secure third-party site. The study materials will be shipped out to your home or office the same day.

Tech Tip Tuesday: Q & A With NTCA Technical Trainer Robb Roderick


I have someone in Florida who is arguing that he has never heard of needing a crack suppression membrane for glass, particularly in pools. Can you suggest some verbiage here?


Thank you for contacting NTCA. On page 8 of the glass tile selection and installation guide in the TCNA handbook. It states, “glass tile is generally more vulnerable to crack propagation than ceramic tile. Where opacity allows, the glass tile manufacturer may recommend the use of a ANSI A118.12 crack isolation membrane for large format glass.

Also, on page 21 in the membrane selection guide, glass tile is listed as material in which  crack isolation membranes can eliminate cracks caused by in plane movement of the substrate.

On page 94 it shows method F125 for installation of crack isolation membranes. The handbook also shows Method P601 and P602 for pool and water features.


-Robb Roderick,

NTCA Technical Trainer

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