Waterproofing
of large retail basement in Nottingham
by Safeguard
The basement to
be waterproofed consisted of a large retail area beneath a store in
Nottingham's central Listergate shopping district. The whole basement area
had suffered from problems with water ingress which the owners of the
property had wished to rectify before letting the basement to new tenants.
The chosen basement waterproofing solution consisted primarily of an
Oldroyd cavity drainage system designed to divert water entering the
basement towards sump chambers containing pumps which discharged the water
outside the building. Certain areas of the basement were better-suited to
waterproofing by means of a more traditional "tanking" approach.
Various products from the Vandex range of cementitious waterproofing
slurries were used in these areas.
The installation
of the basement waterproofing system was carried out by specialist
waterproofing contractor member Peter Cox Ltd. Oldroyd Xv20 high-profile cavity drainage membrane
was used to cover the 1100m2 floor area. This membrane has a large 20mm
stud size which creates an extra-large cavity behind the membrane,
allowing it to deal with higher flows of water than standard-sized cavity
drainage membranes.
Oldroyd Aquadrain perimeter drainage channel was laid around the perimeter
of the basement to increase flow capacity at the wall-floor junction.
Further lengths of Aquadrain were laid across the floor at regular
intervals. Jetting points were installed at regular intervals to allow
future maintenance of the Aquadrain channel. A wall area of over 750m2 was
covered with Oldroyd Xv Clear cavity drainage membrane. This was fixed
using special self-sealing fixing plugs.
Vandex
waterproofing slurries were used to waterproof certain areas of the
basement. This allowed the design of the waterproofing system to be
greatly simplified. For example, the use of Vandex BB75 waterproofing
slurry to tank an area of retaining wall behind a staircase offered a far
more straightforward solution than could have been achieved using a cavity
drainage membrane.
Together, these
measures form a managed water disposal system and are designed to channel
water entering the basement towards ten sump chambers containing dual sump
pumps. Any water entering the sump chambers is discharged outside of the
building by the pumps.
This case
study has been submitted by a member and the British Structural
Waterproofing Association accepts no responsibility for its content. The
photographs in this case study are the copyright of Peter Cox Ltd.
