b'TECH TALK is an important factor to know priorIfso,theareawouldneedtobe to installing tile and is required bydesigned for increased water expo-certain municipalities. sure as outlined in the membrane WithintheTCNAHandbook options within the TCNA F141-19. methods,suchasF141-19,theTypically, in this type of situation, diagramshowstheoptionforatheflashingconnectionstothe membraneandbelowthedia- wallsandanydrainsneedtobe gramitstates,*Useofamem- addressedtocreateacomplete braneisoptional.Seemembranewaterproof system.options. Does that mean a mem-braneusageisoptionalatthe discretionoftheinstaller?No, first,itsimportanttounderstand thedesignedusageofthespace anditsEnvironmentalExposure Classification.TheEnvironmental ExposureClassificationsectionin the TCNA Handbook is often over-lookedandyetitholdsawealth of information with regards to the intended usage of a space and thus theproperclassification.These classifications are divided into two categories,residential(res)andCommercial kitchen maintenance prac-commercial(com).Boththeresi- tices vary widely. Some are routinely dentialandcommercialcatego- saturated during cleaning and require a ries are further divided into sevenmembrane.separate classifications, each withAs you can see, there are a lot of its own expected water exposure. considerations for the proper selec-Intheexample TCNAF141-19,tion and use of waterproof mem-theareaisdesignedwithlim- branes. If you have specific ques-itedwaterexposurehasaratingtions, contact a membrane manu-ofRes1,2/Com1,2.Ifthisspacefacturer and they can help with the is going to be used as a commer- correctchoiceofmaterial.Some cial kitchen for instance, this areamanufacturersevenprovidejob istypicallydesignedwithlimitedsitesupportfortheproperinstal-water exposure in mind, giving it alationoftheirmaterial.Illleave Com2 usage rating. The differenceyou with my simple rule of thumb, couldbeassimpleashowtheif its going to see water exposure, spaceiscleaned,dotheyintendwaterproof itbecause in the end to hose down the walls and floor?its cheaper than a failure.78TileLetter | December 2019'