b'ASK THE EXPERTSAsk the Experts Q&As are culled from member inquiries to NTCAs Technical Support staff. To become a member and make use of personal, targeted answers from Technical Support staff to your installation questions, contact Jim Olson at jim@tile-assn.com.QUESTION ANSWER 2ImlookingforastraightforwardFor a straightforward overview of synopsisofDCOFratingrequire- the DCOF, go to the 2019 edition ments for interior and exterior tile.oftheTCNAHandbookonpage Im finding a lot of long-winded arti- 4. You should also review the ANSI cles, but nothing clear and concise,A137.1 Specifications for Ceramic especially related to exterior. Do youTilesection6. know where I could find that? pages15-16andsection9.6.1 found on pages 24-29.ANSWER 1 As you review this standard, you Im not aware of a simple formulawillfindthisstatementinpart, for determining required DCOF for aThe standard now requires a mini-given installation. mum wet DCOF AcuTest value of Tiles are tested to determine their0.42 for ceramic tiles for level inte-DynamicCoefficientofFrictionrior spaces expected to be walked usingamachinethatmimicstheupon when wet.start/stop/pivotmotionofahumanTheDCOFtestisconduct-step. The test is done with the tileedusingtheBOT3000,oran lyingflatandaslightlyslipperyequivalent, to test individual non-liquidappliedtoitssurface.Theinstalledtilesusingasolutionof testing machine produces a decimalSLS(Sodium-LaurylSulfate)ina number, e.g. 0.42, that depicts the0.05% concentration with the BOT slip resistance of the tile under the3000 traveling 10 across the test-prescribed test conditions. ed tile. Realize that the tested tile A tile with a DCOF rating of 0.42and tiles out of the box may and may work well in a given situation. Differingsituationsmayrequirea differentDCOF.Forexample,an exteriorpublicpooldeckthatis pitched for drainage and is exposed toverywetconditionswilllikely need a tile with a higher DCOF than a private bath floor that is flat, has occasional use and gets slightly wet. The BOT 3000 is a device for measur- Mark Heinlein,ing the dynamic coefficient of friction (DCOF) of ceramic tile and many other NTCA Training Director hard surface floorings.26TileLetter | March 2020'