b'TECH TALK About that grout joint widthBy Paul Makovski, President, Riata GroupThere are many factors to considercanalsobesetto1/16forall before selecting an appropriate groutapplicationtypes.Insomeappli-joint width for porcelain and ceram- cations,likeakitchenbacksplash, ictiles.Factorsthataffectproperanarrowjointmaybeattainable. specifi cation,bywayofexampleHowever,selectinganarbitrary butwithoutlimitation,includethefl oor grout joint width as narrow as tilesdimensionaltolerancessuch1/16forpurelyaestheticreasons, asallowablewarpingandoutoforperceivedmaintenance,canbe squareper ANSI A137.1manufac- extremelyproblematicnotjustin turing standards, fl fl sizeterms of the tile assemblys structure,oor atness, oftheareabeingtiled,andthebut also may not be attainable across presence of movement joints in thelarge areas while keeping adjacent subfl oor per ANSI A108 installationrows aligned. There have been great standards.Onealsoneedstocon- advancementsinmanufacturing siderexposuretoexcessivemois- technologiesofbothcementitious ture, direct sunlight and temperatureand non-cementitious grouts as well swings based on the fi use andasgroutadditivesovertheyears,nal application. Both vertical and hori- allowing highly stain-resistant prop-zontal applications can be affectederties to prevent, and in some cases by all of these factors, which in turneliminate, the age-old struggle with can cause movement and tension inkeeping grout joints clean. the fi nished tile assembly.It is not only important to under-There is a general misconceptionstandtheintentofindustryand thatbecauseANSIA108setsitsmanufacturersrecommendations minimum recommended joint widthprior to joint width specifi cation, but limit to 1/16and grout manufac- alsounderstandthefunctionand turersproducegroutsthatcanbenecessity of grout in a tile applica-appliedasnarrowas1/16thattionasawholepriortoselecting theminimumsuitablejointwidthajointwidth. Theroleofgroutis 76 TileLetter | November 2019'