ASK THE EXPERTS QUESTION I have a quick question about how much slope a shower bench or shower dry-off area should have. The TCNA Handbook states that “All horizontal surfaces, for exam- ple shower seats, sills, curbs, etc., must slope towards drain.” Shower floor slope is 1/4" per foot. Are the other horizontal sur- faces (bench, etc.) also supposed to be 1/4” per foot? ANSWER Yes, the correct slope for all horizontal surfaces is 1/4" vertical (minimum) up to 1/2" (maximum) for every 12” of horizontal run. – Mark Heinlein, NTCA Training Director QUESTION I'm a tile contractor, and need information about certification for thin porcelain slabs. Please contact me. ANSWER Please visit our website to view the locations we have scheduled for GPTP training in 2019 at this link: https://www.tile-assn.com/page/ REGIONALTRNGPROG Please note that some of the programs listed at this link are Substrate Prep / LFT classes. The GPTP classes are scheduled for: • Louisville, KY • Plymouth, MN • Denver, CO • Bethany, CT • Seattle, WA • Norcross, GA Since these courses are in high demand, I suggest registering early. There is no fee to attend these classes, however $50.00 is charged at registration to hold your seat. The $50 is refunded when you attend. – Mark Heinlein, NTCA Training Director Ask the Experts Q&As are culled from member inquiries to NTCA’s Technical Support staff. To become a member and make use of personal, targeted answers from Technical Support staff to your installation ques- tions, contact Jim Olson at jim@tile-assn.com. Image courtesy of Ceramic Tile Education Foundation 28 TileLetter | July 2019