Page 96 - Construction Waterproofing Handbook

BELOW-GRADE WATERPROOFING 2.59

FIGURE 2.75 Expansion joint treatment using sheet system. (Courtesy of Grace Construction Product)

properties to be effective. Precaution must be taken to ensure the confined space is adequate
for clay to swell. If insufficient, materials can raise floor slabs or cause concrete cracking
due to the swelling action.
Clay systems have the major advantage of being installed in various stages during con-
struction to facilitate the shortening of the overall building schedule or reducing any impact
the waterproofing system installation might have. Clay systems can be installed before con-
crete placement by adhering the waterproofing product to the excavation lagging system as
shown in Fig. 2.80, or against slurry walls or similar excavation and foundation support sys-
tems as detailed in Figs. 2.81 and 2.82.
Clay systems can also be applied to the inside face of concrete formwork that is
intended to be left in place due to site access constrictions; a similar installation photo-
graph in shown in Fig. 2.83. These application methods permit the contractor to provide
an effective waterproofing installation without having to delay the schedule awaiting the
concrete placement and curing time necessary for other types of below-grade products.
This also holds true for the typical waterproofing of elevator pits shown in Fig. 2.84.
Here the clay panels are laid directly on the compacted soils before concrete placement,