TECH TIP TUESDAY: ASK MARK – 11/28/17

Contractor Member Question

Mark,

The photo attached shows a stain in the marble, my client used stone poultice to pull out the stain, then sealed the tile. Everything was fine until she took a shower for the first time, and the stain reappeared. What are your thoughts?

 

 

 

 

 

 

 

 

Mark’s Response

Thank you for contacting the National Tile Contractors Association.
It appears to me the stain (or darkening) may possibly be caused by water pooling beneath the tile in a potential low spot formed in that section of the shower pan.  Do you know if the darkening of the stone lightens with time / as it dries out?  It may or may not be a possibility that the initial removing of the “stain” by application of a poultice may have been coincidental to the stone simply drying out (i.e. from mortar curing under the stone).
I have attached a copy of the NTCA’s Mesh Backed Stone and Tile white paper.  This may shed some more light on the issue with this installation.
Many sealers protect the molecular structure of the tile from staining but do not keep water from passing into the stone and potentially darkening it. To learn more about how sealers work, here is a link to a complete listing of NTCA’s archived webinars.  https://www.tile-assn.com/?page=webinars
Please view the webinars I’ve listed below for more information on how sealers work and other relevant information:
I hope this helps.
Mark Heinlein
Technical Training Director

TECH TIP TUESDAY: ASK MARK – 11/21/17

Contractor Member Question

Mark,

Is there a way to determine what a stain on the surface of a tile is? We run into this problem every once in awhile.  I currently have a job that has been complete for a few months and they have sent pictures claiming the spots are thinset, membrane or grout.  I do not believe they are any of those things. Is there a way to tell? Please advise.

Mark’s Response

A recognized tile consultant either owns, or has access to laboratory technology that can test deposits on the surface of tiles.
A list of NTCA’s recognized consultants can be found on the NTCA website at this link:  http://www.tile-assn.com/?page=recconsultants
Any of the consultants listed on this page should be able to assist you.
I hope this helps.
Mark Heinlein
Technical Training Director

Ask the Experts – November 2017

QUESTION

I want to install porcelain tile in my kitchen and my condo association requires a 1/4” cork underlayment for sound mitigation, but my installer and everyone else I’ve spoken with tells me I shouldn’t use cork in a wet area. One installer told me that the NTCA does not recognize 1/4” cork as a suitable substrate for tile applications. Can you tell me if that’s true and, if so, is there some documentation about this that I can present to my condo association?

ANSWER

In the NTCA Reference Manual, cork is listed as a questionable substrate for tile. There are several other bonded sound-reduction membranes that are designed specifically for tile installations. Bonded sound reduction membranes may be trowel-applied, sheet, or composite membranes that are bonded to a suitable substrate so that tile can be bonded directly to the membrane. Their purpose is to reduce floor impact noise.

Material specifications for these products are contained in ANSI 118.13. I suggest finding a substitute for the cork that meets ANSI 118.13. Take the technical data from that product and present it to your condo association for approval. I hope this helps.

Robb Roderick,
NTCA Technical Trainer/Presenter

QUESTION

Can you please tell me what the tolerance for lippage for 6”x 36” plank tile would be? The builder is quoting 1/8” which they said is the thickness of two quarters. The tile seems good the long way but the short way – walking across in your bare feet – you feel it.

ANSWER

The American National Standard Specification for the Installation of Ceramic Tile (ANSI A108) defines acceptable lippage for Pressed Floor and Porcelain Tile that meets the specifications for ceramic tile (found in ANSI A137.1) for typical installations of tile to be as follows:

  • All sizes of Pressed Floor and Porcelain Tiles with grout joint widths of 1/16” wide to less than 1/4” wide: Allowable lippage is 1/32”.
  • All sizes of Pressed Floor and Porcelain Tiles with grout joint widths of 1/4” wide or greater: Allowable lippage is 1/16”.

For reference: 1/32” is roughly the thickness of a credit card. 1/16” is roughly the thickness of one penny.

The plank tile you describe is very likely a Pressed Floor and Porcelain Tile. The manufacturer of the tile can tell you whether it was manufactured to the specifications in ANSI A137.1 (it is usually printed on the carton).

I would be happy to discuss any questions your builder or tile installation contractor may have about lippage or other installation standards that can have an effect on lippage.

Mark Heinlein – CTI #1112,
NTCA Training Director;
Technical Trainer / Presenter

QUESTION

Does a shower pan membrane need to be a solid, continuous piece, or is it all right if one corner is completely sliced up and then caulk applied to all cracks? It seems unsafe, and the weight of the concrete and tile could break open all of the cuts. Please help. Thank you very much.

ANSWER

It sounds like you are having a traditional mortar bed type installation constructed that utilizes a waterproofing liner over a pre-sloped pitch.

It is critical to install this, or any type of waterproofing system, in a manner consistent with tile industry methods and standards and manufacturer’s instructions. Rips, tears, cuts, punctures and improperly-sealed seams lead to leaks and failures of the system. With any type of shower installation, I recommend conducting a water test of the system before mortar is placed. In many locales, this is a code requirement placed on the plumbing permit.

The proper methods and details to construct this and many other type of shower pan installations can be found in the TCNA Handbook. If your contractor is a member of the National Tile Contractors Association they will have a copy of this handbook and know how to use it. They should also have a copy of the ANSI A108 standards that provide detailed instructions for the requirements of mud bed installations.

I will be happy to speak to your installation contractor to help them with any questions they may have about this or any other installation. Please feel free to have them contact me. If they are an NTCA member, they are familiar with this service we provide our members. If they are not a member, I would be happy to discuss with them the many benefits of membership including technical support, free training opportunities and obtaining and using the industry standards to base their installations on.

I hope this helps!

Mark Heinlein – CTI #1112,
NTCA Training Director;
Technical Trainer/Presenter

October 2017: TileLetter – Ask the Experts

QUESTION
I have a floor installation with a relative humidity reading of over 90%. Can you advise me of steps I might take to prevent a failure in this installation?

ANSWER
This is a very high reading and beyond the capabilities of most setting materials. In general, most setting products perform well with readings of 3 lbs/1,000 sq. ft./24 hours in calcium chloride test, or readings less than 75% using a relative humidity test. The effect of moisture on floor covering is a huge problem across the United States. Not addressing this issue with a moisture mitigation system will affect the longevity and performance of this installation and probably lead to some type of failure. Some manufacturers have moisture mitigation systems that include waterproofing membrane, and specific thinset mortars that are warrantable up to 12 lbs/1,000 sq. ft. and above 90% relative humidity. My advice to you is to use a moisture mitigation system and the appropriate setting materials that can handle that level of moisture.

There are thousands of setting products that are affected by differing
amounts of moisture in a variety of ways. Using the information
you have received from a relative humidity test in concert with technical data from your setting material provider is paramount for a successful installation.
– Robb Roderick,
NTCA technical trainer/presenter

 

 

 

 

 

 

QUESTION
I was helping a friend with a concrete shower base install and ran into a problem. We poured the concrete base with the required portland cement/sand mixture at
the correct slope. About a month after the tile install, the grout started chipping out. After regrouting it continued to fall apart. We pulled up the tile and it came up pretty easy. It’s been about five days now and the concrete still looks wet. I cleared out the area around the drain to make sure the weep holes were clear and they were. Why is the base still wet? I’m hesitant to install new tile on top until it’s dry. Help please!

ANSWER
Can you tell me if a pre-slope of a 1/4” per 12” was installed first then a liner placed over the preslope and sealed to the clamping ring drain, then the mud pack over that?
Or, was a surface-applied waterproofing membrane installed on top of the sloped dry pack mud bed and sealed via the divot method to the clamping ring drain? If not, the mud pan is going to hold water if there is no membrane channeling it to the drain system.

Showers and pans are complex systems that must be installed properly to protect the rest of the structure they are installed in. I strongly suggest hiring a qualified professional to perform this installation. The NTCA is the world’s largest association of tile contractors. You can locate an NTCA Member contractor and a Certified Tile Installer in your area by visiting the following sites: www.tile-assn.com or www.ceramictilefoundation.org.

– Mark Heinlein,
NTCA technical trainer/presenter

 

 

 

 

 

RESPONSE
Thanks for the quick reply. It looks like I did all of the correct things outlined in your email with exception of the divot method. Now after reading up on the divot method I have questions. Does it require a drastic slope to the drain as shown in the picture
below? Also does this method call for a paint-on membrane to be put on the very top? Let me know and thanks again for your time.

 

 

 

 

 

 

 

ANSWER
Either a liner on the pre-slope or a surface-applied membrane must be used. Not both. Whichever one is used, it must be properly sealed to the clamping ring drain. The divot allows for using a surface-applied membrane in lieu of a pre-slope and a liner with a clamping-ring drain system. Or, a bonding-flange drain system can be utilized to accommodate a surface-applied membrane. There are many variables, techniques, best practices and standards that must be considered, applied and performed correctly in every tile installation. Showers and wet areas are especially critical.

I suggest contacting a qualified, certified, knowledgeable, experienced professional using the links I sent previously. – M.H.
RESPONSE
Mark, thank you. I did the liner on the pre-slope so I should be
okay. I just wasn’t sure why the base retained so much moisture even with the liner, slope, and weep holes all in working order.
ANSWER
Drainage issues could potentially be related to the site mix/recipe or consistency of the mix, method of application, etc. Perhaps the problem with the grout could be related to the type and mixing and application of grout or the type and mixing of the mortar and troweling technique used to bond the tile to the mud pack. – M.H.

Tech Tip Tuesday: Q & A With NTCA Training Director Mark Heinlein – 10/31/2017

Consumer Question:

Hello! I’m trying to find out if there is an industry standard for the conversion rate of m to kg for Porcelain tiles based on thickness and if so, where I would be able to find this information. Thank you in advance for your assistance.

Mark’s Response:

Thank you for contacting the National Tile Contractors Association.

The Tile Council of North America (TCNA) Handbook for Ceramic, Glass and Stone Tile Installation contains an Appendix (B) discussing “Estimated Weights for Floor Installations.”

This appendix provides a discussion of assumptions for dead load weights of ceramic and stone tile and related setting materials. The assumptions are given in terms of imperial / US Customary (pounds per square foot) measurement vice metric (kilograms per square meters).  Several tables giving the weight calculations for methods included in the handbook are provided in Appendix B.

If you do not own the TCNA Handbook, a copy can be purchased from the NTCA’s Online Store under the Industry Technical Manuals section at this link:  https://tile-assn.site-ym.com/store/default.aspx?

I hope this helps.

 

Mark Heinlein

NTCA Training Director

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 www.tile-assn.com for more information.  You can view additional member benefits at this link:  http://www.tile-assn.com/?page=Membership  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

TECH TIP TUESDAY: Q & A WITH NTCA TRAINING DIRECTOR MARK HEINLEIN

Question:

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: https://tile-assn.site-ym.com/store/ListProducts.aspx?catid=398904

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:  https://tile-assn.site-ym.com

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: https://tile-assn.site-ym.com/?page=whyhire

Locate an NTCA Contractor: http://tile-assn.site-ym.com/search/custom.asp?id=2759

Why Hire a CTEF Certified Tile Installer: https://www.ceramictilefoundation.org

Locate a CTEF Certified Tile Installer:  https://www.ceramictilefoundation.org/find-certified-tile-installers

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

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