BUSINESS TIP –––––––––––––––––––––––––––––––––––––––––––––––––––––– Mapeguard® UM is a light- weight, waterproofing and vapor pressure-equalizing underlay- ment membrane from MAPEI. It provides crack suppres- sion for use under ceramic tile and stone installations, for both resi- dential and commercial applications. M a p e g u a r d UM is designed to perform over challenging substrates, such as young con- crete and single-layer 3/4” (19 mm) plywood subfloors with joist spacing of up to 19.2” (49 cm) on center. The unique engineered tri-layered design of Mapeguard UM absorbs lat- eral stress from the substrate without transferring this force to the tile or stone, which maintains exceptional bonds. www.mapei.com. installation; I know that a tile job can fail for many reasons. Before I retired last year from my job teaching high school English, I never thought about mortar and grout and did not know the difference between NTCA and ANSI and TCNA. But like I said, I’ve learned. Tile is pretty interesting – maybe not as fascinating to me as literature and grammar, but pretty interesting. All that tile-related chem- istry, physics, math and technology makes for some brainy stuff. So anyway, I often listen in on Mark’s calls – sometimes I even pipe in if it is someone I met along the way like a new member who joined at one of our workshops, or Mark’s boss with a “Hi Jim.” Some of the calls are quick; an answer that Mark can rattle off easily. “What is the allow- able lippage for such and such?” or “When is Coverings?” Most of the calls involve difficult situations and complicated questions. I remember one from a few months ago about a swimming pool deck that involved multiple calls and research. Several months ago Mark got a Connie is a Jill-of-all-trades; here she assists Mark in putting education sponsor logos on the new NTCA van she and Mark will be driving all over the country this year. 26 TileLetter | March 2017