This paper is limited to protected type waterproofing membrane assemblies such as plaza decks, split slabs and concrete over wood decks assemblies. Traffic able waterproofing membrane systems like deck coatings and traditional protected roof assemblies such as inverted roof membrane assemblies are excluded from this discussion. Plaza decks are defined as exposed pedestrian surfaces constructed over parking or other occupied space, often built over structural concrete.
IBC defines garages as a type of occupancy, so technically plazas built over garages are over occupied space. Plaza decks can have many features such as driveways, pools, lawns, large mature trees, terrazzo and concrete toppings, glass screens, pavers over gravel or pedestals, planters, etc. Also discussed are protected waterproofing membranes over wood decks surfaced with many of the same types of permanent surfaces such as concrete topping slab, tile planters, etc. Typical Type V Podium assemblies are 4 to 5 stories of wood framed construction over a concrete podium, commonly used in California and other states for multi-family construction.
These elevated wood assemblies also have exposed, horizontal waterproofing with hard wearing surfaces like concrete which are integrated to the exterior wall claddings such as, masonry, stucco, siding, dimension stone, etc. Because these assemblies are surfaced with permanent landscape and hardscape features and integrated with doors, ramps and claddings elements, the wood framed waterproofed assemblies are also built with a life expectancy equivalent to the “life of the building”.