Page 106 - Construction Waterproofing Handbook

BELOW-GRADE WATERPROOFING 2.69

FIGURE 2.88 Clay system detail for foundation water-
proofing without, with horizontal membrane applied directly
to grade. (Courtesy of Cetco Building Materials Group)

FIGURE 2.89 Grade beam detailing for clay system.
(Courtesy of Cetco Building Materials Group)

The variety of bentonite systems available means that applications will vary consider-
ably and have procedures similar to the waterproofing systems they resemble in packag-
ing type (e.g., sheet goods). Bulk clay is applied like fluid membranes. Panels and sheets
as sheet-good systems, and butyl compound-polyethylene systems are applied virtually
identically to rubberized asphalt systems.
With bulk systems, proper material thickness application is critical as it is with fluid-
2
applied systems. Bulk systems are sprayed or troweled, applied at 1–2 lb/ft of substrate.
Panel and mat systems are applied to vertical substrates by nailing. Horizontal applica-
tions require lapping only. These systems require material to be lapped 2 in on all sides.
Cants of bentonite material are installed at changes in plane, much the same way as cemen-
titious or sheet-applied systems. Bentonite sheet materials are applied with seams shed-
ding water by starting applications at low points.