b'Surface prepCONTRACTOR PERSPECTIVEPavlo Starykov forms a non-absorbent coating on the back of the tile that Star Tile & Stone LLC regular thin-set mortar will not properly bond to (even As a professional tile contractor,with presence of coarse sand in the backing).IalwaysstrivetofollowcurrentNot long ago the only mortar that would properly bond industry standards in my installa- to resin-backed tiles was epoxy but in recent years, after tions, but it is of the utmost impor- theintroductionofnewpre-mixed,single-component, tance to understand that the bestlow VOC, rapid-drying primers specifically designed for surfacepreparationpossibleasnon-absorptivesubstrateslikeARDEXP4,LATICRETE wellastheuseofpremiumset- Prime-N-Bond and the tried and true MAPEI workhorse ting materialscan all be in vainEcoPrim Grit, installers can now prime the back of such Pavlo Starykov iftheadhesionbetweenthetiletile and stone and choose among a wide range of adhe-and mortar is severely weakenedsives to install it. and compromised. That can be the case with the resin-backedtilesthathavefiberglassmeshcoatedwithaJim Uptonglue (polyester, urethane, or epoxyshown in photo). Tiger Mountain Tile, Inc.SuchcoatingisusedbydifferentmanufacturerstoFlatfloorsaremoreimportant reinforce unstable stone slabs and tile to reduce the likeli- than ever. And wouldnt you know hood of fracture. The main complication arising from thisit? Along comes new technology in method is that the ability of most (if not all) modified/ self-leveling underlayments (SLU) unmodifiedmortars(thataremostlyportland-cementthat allow them to be poured over based)isseverelycompromisedbecausetheresinwood subfloors with no additional lath reinforcement.Consequently, its my belief that Jim Upton thesenewself-levelingproducts are game changers and will drive this category of products to more and more popularity. After all, who doesnt want a flat floor?These new SLUs can be incorporated right along with the usual tile underlayment products like backer boards and uncoupling membranes. Alternatively, with the abil-ity to be poured 1/4 and thinner, they can also be speci-fied in place of those products if the situation calls for it.We know the trend in tile is bigger and bigger sizes. As a result, weve seen an explosion in tile leveling products, LFT mortars, and bigger tile cutters. So, its only logical to embrace products and techniques that will give us flatter floors.However,itshouldbenotedthatthereisacertain amountofskillrequiredtobeproficientwiththese products.Iknowfromexperiencethatitsnotfunto pour self-leveling underlayment just to end up moving the high spots around. But if contractors are willing to endure some temporary setbacks and embrace the learn-ing curve, they can look forward to a future of beautifully flat floors.802020|TECH'