Water Cleanable Tile-Setting Epoxy Adhesive. The 2018 TCNA Handbook con- tains information about selecting the correct products to install natu- ral stone in these locations: • The Natural Stone Selection Guide near the front of the book includes a subsection “Considerations When Selecting Installation Materials.” • The 2018 TCNA Handbook includes approximately 66 meth- ods for installation of natural stone, including movement joint guidelines. To my knowledge, none of the installation meth- ods for natural stone list organic adhesive as a suitable material for the bond coat. Typical bond coats detailed in the “Materials” section of the stone methods are cementitious or epoxy. The TCNA Handbook’s Setting Materials Selection Guide (page 17 in the 2018 edition) includes a subsection for using “Organic Adhesive” in which it is described as suitable for setting ceramic tile. As you have already discovered, organic adhesive is not identified as a bond coat for installation of natural stone tile. One of the rea- sons is the result experienced in the white marble installation that has yellowed. I have found that some manu- facturer’s technical data sheets for their organic adhesives specifically state they are not to be used for set- ting natural stone. I hope this helps. – Mark Heinlein, NTCA Training Director, NTCA Technical Trainer ASK THE EXPERTS –––––––––––––––––––––––––––––––––––––––––––––––––––– National Tile Contractors Association 626 Lakeland East Drive | Jackson, MS 39232 PO Box 13629 | Jackson, MS 39236-3629 601.939.2071 | 601.932.6117 fax | tile-assn.com The VOICE of the TILE CONTRACTOR The NTCA Reference Manual was devel- oped to identify recurring challenges to successful installations of tile and stone, recognize potential problems,and to gain consensus from industry experts on offering solutions. Now available for purchase in print or digital download.www.tile-assn.com 24 TileLetter | September 2018