Page 44 - Construction Waterproofing Handbook

2.8 CHAPTER TWO

FIGURE 2.9 Below-grade waterproofing application with drainage board used as
protection. (Courtesy of TC Mira DRI)

starting with the lower portion first, lapping higher elevation goods over the already
installed piece to match the manufacturer-supplied flange edges (Fig. 2.11). Drainage
systems can also be applied directly to lagging prior to concrete placement (Fig. 2.12).
The filter fabric material is always applied facing out, and manufacturers provide
additional fabric at ends to overlap all seams. The terminated ends of the material are
covered with the fabric by tucking it behind the plastic core sheet. Side edges of the sheet
are typically attached together by overlapping and applying an adhesive. Figure 2.13
shows a partially completed drainage system installed with appropriate drain field gravel
backfill.
Figure 2.14 details the use of drainage systems for under-slab drainage. Figure 2.15
details the use of these systems for horizontal transitioning to vertical drainage at a below-
grade tunnel installation.