Page 174 - Construction Waterproofing Handbook

ABOVE-GRADE WATERPROOFING 3.63

FIGURE 3.52 Protected membrane application using concrete pavers. (Courtesy of American Hydrotech)

FIGURE 3.53 Protected membrane application using stone pavers. (Courtesy of TC MiraDRI)

DRAINAGE REQUIREMENTS

Protected membranes are used for swimming pool decks over occupied areas, rooftop
pedestrian decks, helicopter landing pads, parking garage floors over enclosed spaces, bal-
conies, and walkways. Sandwich membranes should not be installed without adequate pro-
vision for drainage at the membrane elevation; this allows water on the topping slab, as
well as water that penetrates the protection layer onto the waterproof membrane, to drain
(Fig. 3.56). If this drainage is not allowed, water will collect on a membrane and lead to
numerous problems, including freeze–thaw damage, disbonding, cracking of topping