Leaking Water Pit
Medical Hospital, New York City
Project Scope
Install a flexible membrane liner in a concrete pit that
holds water for a fire suppressant system located in a
major medical hospital.
Challenge
As part of an addition to a major NYC hospital, a pit
was built to hold water for the fire suppressant
system. The pit was designed with water stops, but
the pit leaked into adjacent parts of the hospital. A
water resistant coating was applied but it too failed.
A second attempt at the applied coating also proved
futile.
Solution
The architect for the job selected a flexible liner from
Witt Lining Systems to line the pit. A Witt Liner isn’t
affected by the cracks in the concrete that the applied
coating was unable to bridge in the previous attempts
to repair the pit. A geotextile padding was installed on
the pit walls and floors to protect the liner. The custom
liner was fabricated in one piece and shipped to the
job site for installation. The pipe penetration in the
tank was handled on site by the installation company
with a pipe boot supplied by Witt Lining Systems.
Results
Installation of the padding and liner was completed
over 3 days. Upon completion, the pit was returned to
service. Field reports concluded that no further water
was weeping into other rooms as was the case with
the failed coating. The finished liner is expected to
provide years of worry-free service in the pit
