LARGE FORMAT TILE ––––––––––––––––––––––––––––––––––––––––––––––––– Problem Loss of bond between bond coat and large porcelain tiles or tiles con- taining high percentage of glass in the body. Tiles may come off mortar bond coat clean, even with full cov- erage on backs of tiles. Cause Any of the following may prevent problems with large porcelain and glass-bodied tiles. • Inadequate contact between mor- tar bond coat and backs of tiles which may be caused by improper beat-in and using inadequate amounts of mortar, or worn or improper trowels. • Use of pure cement bond coat over plastic mortar beds. • Use of dry-set mortar without latex additives. • Presence of excessive white pow- der (manufacturer’s release agent) on back of tile. • Bending or deflection of sub- strates. • Differential expansion between tile and setting material. • Working on or too early traffic on newly-laid tile floors. • Shrinkage or setting of substrates due to changes of moisture in struc- ture or movements in the structure after construction is complete. • Improperly engineered structure for the installation put into place. Cure Any of the following may be a cure to problems with large porcelain and glass-bodied tiles. Ultracolor Plus FA with DropEffect™ technology is a fast- setting, non-shrinking grout with fine aggregate for grouting tile and stone joint widths from 1/16” to 3/4” (1,5 to 19 mm). The fine-aggregate formulation makes Ultracolor Plus FA an all-in-one grout replacement for sanded and unsanded grouts. DropEffect technology reduces surface absorption to help repel water, dirt and grime from penetrating grout joints. Features and Benefits: • Easy to install and stain-resistant • Color-consistent • No efflorescence • No sealer required • 10% recycled content TCNA Green Squared Certified® www.mapei.com 82 TileLetter | May 2017