ASK THE EXPERTS QUESTION I have a quick question about back buttering tile requirements. We are installing ceramic and/or porcelain tile according to TCNA spec F113 On-Ground Concrete. The installs are interior residen- tial applications. Where can I find information if back buttering each tile is required? ANSWER For ceramic or porcelain tile of any size, back buttering (also known regionally as “Keying In,” “Burning,” “Back Parging,” etc.) promotes transfer of the bonding material to the back of the tile. Back buttering is not required to achieve necessary coverage and support. Coverage and support is achieved by using an appropriate trowel notch size and shape, direc- tional troweling technique, and mortar selection and mixing. Back buttering is recommended for natural stone tiles to ensure all the voids are filled. Specific language that sup- ports this is found in the Mortar Application and Coverage section on page 35 of the 2017 edition of the TCNA Handbook for Ceramic, Sponsored by e-Learning Program Industry and product information in short, easy segments Train from the comfort of your home or office anytime Fast and easy to access, listen, and complete A-8394-0218 ©2018 LATICRETE International, Inc. All trademarks shown are the intellectual properties of their respective owners. Register today at laticrete.com/university Globally Proven Construction Solutions 22 TileLetter | April 2018