Ask The Experts: July 2017

QUESTION:

I have a client with glass tiles cracking on an install. The GC admitted to not installing with a crack suppression membrane. They also drilled pilot holes for a door install that resulted in cracking. The tiles associated with the holes were installed before drilling. The final comment by the client was the cracking was from the back, and did not come through the face.

In your opinion, is it likely the lack of a crack isolation membrane created the opportunity for all of these tile cracks?

 

ANSWER: 

It appears to me that the crack at the window wall may be related to structural stresses within the framing or deflection in the substrate. The crack at the control valve may be related to structural stresses such as deflection within the substrate that was not well supported at the valve location. The cracks from the drill holes are likely related to the physical and heat stresses placed on the tile during the drilling process and may also be related to deflection in the substrate if the substrate was not well supported in this area. A crack isolation membrane would likely not have prevented the cracking.

There are other potential issues that can cause large-format glass tile to crack. They would include: Incorrect mortar or adhesive selection; mortar cure time (which will vary based on the mortar used and whether a waterproof membrane was used); thermal expansion from light or hot water; lack of expansion joints; deflection in the substrate; etc.
– Mark Heinlein,
NTCA technical trainer/presenter

QUESTION:

I’m dealing with customers who are unhappy about their recent tile installation. They feel the tile has too high a color variation. Could the installer have laid out the tile incorrectly? Whose responsibility is this – the installer’s, or mine? Thanks for your help.

ANSWER:

Per our conversation, on page 2 of the 2016 TCNA Handbook there is a section that deals with aesthetic classification. It specifically talks about variations in color, texture and appearance, and how tile suit- able for TCNA Handbook installations must meet specifications out- lined in ANSI 137.1. This ANSI standard sets performance and aesthetic criteria for many types of tile. Using tile that meets ANSI 137.1 ensures a degree of quality and consistency among tiles.

This chart from CTDA illustrates the ranking of shade variation levels, from the most uniformly shaded V1 to V4, which represents a tile with the highest degree of shade or color variation. A V0 tile is very uniform in appearance and smooth in color, with a color difference of less than 3 Judds when measured by a colorimetric spectrophotometer.

Tiles can have a V (variation) designation from V0 to V4. V0 tiles are very uniform in color and shade. V2, V3, V4 tile all increase in their randomness of color with V4 being the most random. Is the tile in question an ANSI 137.1 tile and what is its V designation?

The TCNA Handbook says that tile should be installed from several boxes in a random fashion to avoid aesthetic issues. Are you aware if the installer did this? How much was installed before the variations were noticed? How quickly did the installer report this to you?

It is common practice in our industry to report any defects or issues with the tile prior to installation. Many tile manufacturers even have disclaimers on their boxes explaining that claims against the tile must be made prior to installation. Let me know the answers to these questions and I will try to help you further.

– Robb Roderick,
NTCA technical trainer/presenter