Page 56 - Construction Waterproofing Handbook

2.20 CHAPTER TWO

FIGURE 2.27 Field welding operation of PVC waterstop.
(Courtesy of J.P. Specialties)

Photographs in Figs. 2.31 and 2.32 show how complicated waterstop installations can
become. Such detailing necessitates the use of premanufactured weld splices to ensure
watertight applications. These photographs also emphasize how important proactive job-site
quality-control procedures are, to verify that the PVC waterstop is installed and maintains
proper positioning during concrete placement.

HYDROPHILIC/BENTONITE/ASPHALT RUBBER

These systems are all installed after the first concrete placement has occurred, with the
materials attached directly to the first half by a variety of methods. The waterstop is sup-
plied in rolls in lengths of several hundred feet and the material is adhered to the substrates
by a variety of methods as recommended by the manufacturer.
Typically, the concrete does not need to be cured completely, as this would interfere
with the placement schedule of the concrete. Substrate preparation is usually minimal,
ensuring that there are no form release agents, fins, or other protrusions that can damage
or puncture the waterstop during installation. Attachment is completed by a variety of
methods, some as simple as nailing the strip to the concrete to hold it in place temporarily
until the second half of concrete placement occurs.