b'ASK THE EXPERTSmer. Since then, chemists were ablenPolyvinylacetateisessentially tomodifytheperformancecharac- ElmersGluetypematerial.When teristics of these polymers even moreputintothehighpHofcement, byaddingadditionalmonomerstoPVA will hydrolyze to form polyvi-the chain. Monomers such as vinylnyl alcohol. This is not a good thing versatate and vinyl laurate have beenbecauseasyoumentioned,the addedtosubstantiallyincreasethepolymer re-disperses when wet and polymersresistancetowater.Allwill adversely affect mortars.of these variations generate a wide assortment of polymers from whichTomyunderstanding,typically, thesettingmaterialsmanufacturerstile adhesive manufacturers do not may choose. A polymer with moresell or promote the use of PVA for ethylenewillimpartmoreflexibil- ceramic tile installations. Most man-ity to the finished product than oneufacturers will utilize alternate pro-withlessethyleneifthepolymersprietary lattices or alternate chem-are blended with the same cement/ istries that are stable in cement and polymerratio.Themanufacturerprovide all of the proven required must determine what the desired per- characteristics(e.g.strength,flex-formancecharacteristicsofaprod- ibility,moistureresistance,freeze/uct should be and then choose thethaw stability, etc.). proper polymer and cement/polymer ratio to put in the finished product to Mark Heinlein, achieve their goals. NTCA Training Director26TileLetter | August 2020'