TECHNICAL FEATURE ––––––––––––––––––––––––––––––––––––––––––––––––– deck structures, any failure may come back to haunt you. In my travels across the country, a very common and consistent thread emerges with regard to exterior work when a qualified installer – be it residential or commercial – chooses to use a crack-isolation/waterproofing membrane, intended for interiors, outside. If one reads the “small print” for many of these products, these facts will often emerge: • The membranes in question are specifically not designed, approved, or warranted as pri- mary waterproof membranes over occupied spaces for exterior applications • The ANSI A118.12 crack-iso- lation properties for many of these indoor products will not hold up, or be warranted against the rate of thermal expansion and contraction in exterior applications. To add to the product-selection challenges, installation profile lim- itations, and shortcomings, there are often time-crunch implications – in which the installer is tasked to deliver a finished product – that may conflict with the time require- ments of some crack-isolation and waterproofing products. The stakeholders involved with the Bellagio pool deck and people mover were well aware of all of the issues raised when this remodel project was being drawn up and put to bid. Be sure membranes in question are spe- cifically designed, approved, or warranted as primary waterproof membranes over occupied spaces for exterior applications Dal-Deck, a private-label version of Noble Deck supplied by Daltile, being applied to the people mover at the Bellagio 68 TileLetter | November 2017