a mechanical bond, and make claims that a latex-modified thinset can be used. I know people have scarified and or primed the back of these tiles in order to use modified thinset. Without the endorsement of the thinset manufacturer and the stone provider, these installations are risky. I would proceed with caution. – Robb Roderick, NTCA trainer/ presenter QUESTION I installed a large resin-backed marble tile on a fireplace wall with a glass-covered fireplace insert that produces a lot of heat, and mea- sured tiled surface temp was about 250+ degrees in direct vicinity of the firebox. I have several issues. Issue one – We used a polymer- modified thinset to install the tile. I didn’t realize till after the job was done that it does not stick to resin- backed tile. Issue two – Upon further research I should have used an epoxy thin- set, but from what I was told it is only okay for temps up to 180 degrees. Issue three – Is the resin on the back of the tile okay to be in con- tact with that kind of heat? I am receiving very little help from my tile supplier, I have a very unhappy client, and I am eager to make the fix but I need to know the correct approach so I don’t have a problem again. Thanks in advance for your help. New and improved, LATICRETE® NXT™ Skim is a premium quality, fast- drying, cement-based underlayment designed for skim-coating, smoothing and leveling prior to the application of floor coverings. The improved formula can now hold more water, resulting in a creamier consistency for a smoother application and sleeker finish, as well as an extended pot life and easier troweling. In a first amongst skim-coating prod- ucts, the NXT Skim packaging has also been redesigned with a tin tie reseal- able feature that allows the product to be saved for additional uses, minimiz- ing product waste and increasing cost savings for the installer. NXT Skim can be applied from skim depth to 1” (0 - 25 mm) and the finished flooring can be installed as soon as 20 min- utes after application. Designed to meet UL GREENGUARD® certification standards for low chem- ical emissions, the new NXT Skim can be utilized at high-profile job- sites, including hospitals and schools. www.laticrete.com. ASK THE EXPERTS –––––––––––––––––––––––––––––––––––––––––––––––––––– 24 TileLetter | December 2017