suspect any of the concerns listed below may exist in the installations that are exhibiting crazing? • Proper / improper installation and cure time of the liquid water- proofing membrane • Excessive bond coat thickness • Proper / improper cure time prior to grouting • Change in plane movement joint installation You mentioned you are not able to determine the quality of the fram- ing or whether there is deflection in the substrate. Are you able to learn from the building’s owners or build- ing records whether there is wood or metal framing and whether the framing on the failing installations was properly braced to support a tile installation? Was the board properly gapped between sheets at horizontal and vertical joints, filled with Portland cement mortar and taped with alkali-resistant mesh tape? Were open joints left between the boards where they meet at inside cor- ners to allow for movement at the change in plane? As you can see, I have more questions for you than answers at this point. Some, or a combination of the items described above may have an effect on the system perfor- mance. I suggest starting with the tile manufacturer and determining whether the tiles have been tested to ANSI A137.1 specifications and if there may be a correlation or con- cern with the lots that are failing. ASK THE EXPERTS –––––––––––––––––––––––––––––––––––––––––––––––––––– The new LATICRETE® STRATA_ HEAT™ electric radiant floor heating system consists of the world’s first heat conductive thin- set additive that utilizes Thermal Diffusion Technology™ to uni- formly distribute heat through the adhesive to eliminate cold spots and quickly achieve the desired floor temperature. The system also includes an inno- vative high-performance floor heating wire, an uncoupling mat and a Wi-Fi enabled thermo- stat. The advanced system trans- fers heat faster than standard floor heating products on the market to reduce energy costs and provide customers with the most customizable floor heat- ing experience imaginable. www. 16 TileLetter | 2018