BY T HE BOOK brought to you by NTCA Reference Manual now addresses stone discoloration in wet areas One of the new documents the NTCA Technical Committee is includ- ing in the 2017 Reference Manual this fall addresses potential concerns when natural stone is installed in wet areas, especially on shower floors. Recently, with many new stones entering the market, it seems that some of these materials at times experience discoloration, and the cause, cure and prevention or correction of this discol- oration is unknown or may be difficult to correct. The NTCA felt the issue is significant enough to draft a document and disclaimer that highlights the con- cern and alerts the tile contractor to request in writing from the supplier or homeowner/builder that the material is suitable for wet areas. There is a separate document that supports the contractor in the case of stone discoloration on a project. It contains recommendations for stone selection, installation materials, instal- lation methods and additional con- siderations. It goes on to also request installation recommendations so that the proper materials are used for the natural stone. In many instances, ceramic or porcelain tile substitutes, especially for the shower floor area – where the most discoloration seems to be taking place – could also be considered. It is also recommended to document each phase of the show- er assembly with photographs and records of all products used. Examples of discoloration are also provided in the documents. Forensic investigations by recognized consultants in the industry have deter- mined that there is reasonable concern that some of these stones are being discolored, even though the tile instal- lation was done according to industry standards. This determination led the NTCA Technical Committee to develop the disclaimer that alerts the client/proj- 62 TileLetter | September 2017