CLAY SYSTEM APPLICATION - WATERPROOFING AND CONSTRUCTION

Natural clay waterproofing materials require the least preparatory work of all below-grade systems. Concrete substrates are not required to be cured except for rubberized asphalt combination systems. Concrete can be damp during installation, but not wet enough to begin clay hydration.

Large voids and honeycombs should be patched before application. Minor irregularities are sealed with clay gels. Most concrete curing agents are acceptable with clay systems.
Masonry surfaces should have joints stricken flush. Note the standard application detailsin Figs. 2.87, 2.88, and 2.89.

FIGURE 2.87 Clay system detail for foundation water-
proofing using mub slab.

FIGURE 2.88 Clay system detail for foundation water-
proofing without, with horizontal membrane applied directly
to grade.

FIGURE 2.89 Grade beam detailing for clay system.

Bentonite materials combined with butyl rubber require further preparation than other clay systems, including a dry surface, no oil or wax curing compounds, and no contaminants, fins, or other protrusions that will puncture materials.

The variety of bentonite systems available means that applications will vary considerably and have procedures similar to the waterproofing systems they resemble in packaging type (e.g., sheet goods). Bulk clay is applied like fluid membranes. Panels and sheetsas sheet-good systems, and butyl compound-polyethylene systems are applied virtuallyidentically to rubberized asphalt systems.

With bulk systems, proper material thickness application is critical as it is with fluid-applied systems. Bulk systems are sprayed or troweled, applied at 1–2 lb/ft^2of substrate.

Panel and mat systems are applied to vertical substrates by nailing. Horizontal applications 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 cementitious or sheet-applied systems. Bentonite sheet materials are applied with seams shedding water by starting applications at low points.

Outside corners or turns receive an additional strip of material usually 1 ft wide for additional reinforcement (Fig. 2.90). Chalk lines should be used to keep vertical applications straight and to prevent fish mouthing of materials. All end laps, protrusions, and terminations should be sealed with the clay mastic, as shown in Figs. 2.91 and 2.92. Proper termination methods are shown in detail in Figs. 2.93 and 2.94.

FIGURE 2.90 Clay system applied to lagging detailing. Note reinforcement at corner.

FIGURE 2.91 Typical penetration detailing for clay system.

FIGURE 2.92 Pile cap detailing for clay system.

FIGURE 2.93 Termination detailing for clay system.

FIGURE 2.94 Termination detailing for clay system
using reglet.