Page 41 - Construction Waterproofing Handbook

BELOW-GRADE WATERPROOFING 2.5
The products aid in the drainage of
groundwater by collecting and conveying
the water to appropriate collection points
for drainage away from the structure. A sim-
plified typical design is shown in Fig. 2.7.
The products provide low-cost insurance
against water infiltration and should be
used with every below-grade waterproofing
application (with the possible exception of
hydrous-clay materials). More often than
not, the drainage systems can be used in
lieu of protection board for most mem-
brane applications, effectively negating
any additional costs for the system’s superb
protection.
Besides the additional drainage protec-
FIGURE 2.4 “T” connector for drainage system.
(Courtesy of American Wick Drain Corporation) tion for occupied spaces, the systems are
also used alone for protecting various civil
structures such as landfills and retaining
walls or abutments. Among the many uses
for manufactured drainage systems:

● Below-grade walls and slabs
● Retaining walls and abutments
● Tunnels and culverts
● Lagging
● Embankments
● Landfills
● French and trench drains (described in the
previous section)
● Drainage fields for golf courses and other
park and play field structures
● Specialized drainage requirements
FIGURE 2.5 Outlet connection for drainage sys- ● Above-grade plaza decks and similar
tem. (Courtesy of American Wick Drain
Corporation) installations (covered in Chap. 3)
The system is similar to the prefabricated
soil drainage systems only available in larger sheets and drainage cores to facilitate drainage.
The material consists of a formed plastic three-dimensional core that acts as the collector and
drainage transporter of the water, as shown in Fig. 2.8. The plastic drainage product is also
covered with a geotextile fabric to prevent the silt, soil, clay, and sand from clogging the
drainage system. The systems usually have some type of plastic sheeting adhered to one side
to protect from indenting waterproofing membranes as well as acting as an initial water-
proofing system.