Page 179 - Construction Waterproofing Handbook

3.68 CHAPTER THREE
Topping slabs must have sufficient strength for expected traffic conditions. Lightweight or
2
insulating concrete systems of less than 3000 lb/in compressive strength are not recommended.
If used in planting areas, membranes should be installed continuously over a structural deck and
not terminated at the planter walls and restarted in the planter. This prevents leakage through the
wall system bypassing the membrane. See Fig. 3.68 for the differences in these installation meth-
ods. Figure 3.69 represents a typical manufacturer detail for a similar area.
Using below-grade membranes for above-grade planter waterproofing is very common,
especially on plaza decks. While these decks themselves are often waterproofed using the
techniques described in this chapter, the planter should in itself be made completely water-
proof to protect the building envelope beneath or adjacent to the planter.
Figures 3.70 and 3.71 detail the typical
application methods of waterproofing above-
grade planter areas. Note that each of these
details incorporates the use of drainage board
to drain water towards the internal planter
drain. Since these areas are watered frequently,
drainage is imperative, in this case, not only for
waterproofing protection but also for the health
of the vegetation planted in the planter.
Figure 3.72 shows the application of liquid
membrane to planter walls as does Fig. 3.73. In
the latter note how difficult the use of a sheet
good system would be in this particular appli-
cation. Whenever waterproofing above-grade
planters with tight and numerous changes-in-
plane or direction, liquid applied membranes
are preferred over sheet-good systems as the
preferred “idiot-proof” application. The con-
FIGURE 3.61 Drainage system detailed into gut-
ter system. (Courtesy of Schluter Systems) tinual cutting of sheets in these smaller appli-
cations results in a corresponding number of

FIGURE 3.62 Expansion joint detailing for topping slab construction. (Courtesy of Anti-Hydro
International, Inc.)