rainwater. Incredibly strong and needing only
minimal cover, they are the ideal solution for
managing surface water run-off.”
Weighing only 18 kg per module and measuring
1200 mm x 600 mm x 420 mm, the modular units can
be easily lifted by hand and then laid or stacked in rows.
The units are suitable for a range of applications includ-
ing residential, commercial and industrial projects.
The modules can be wrapped in a geotextile which
allows stored water to slowly seep into the surrounding
ground and back into the water table. A more common
practice, is to wrap in an impermeable geomembrane
to create a sealed underground tank.
The sealed tank approach was adopt-
ed at the new primary school, with the
outlet from the tank then controlled to
facilitate a slow release of the stored wa-
ter back into the drainage system over a
Manufactured from recycled plastic,
they have a high void ratio of 95% which
means that each crate is capable of stor-
ing up to 300 litres of water in the event
of heavy rains. If inspection is required
for future maintenance, then Brett Martin
can offer StormCrate Inspect Crates.
There are no limits on the use and
design of the surface over the system and they may be
successfully installed under parking areas, driveways
and landscaped areas. Ideal for domestic soakaways,
only 250mm of cover is required above the crates for
driveway applications which results in less dig and site
For more challenging applications the lorry bearing
design ensures extreme load capacity due to StormCrates
stable column structure which provides a SLW 60-bear-
ability with a 500 mm covering which represents a ve-
hicle of up to 60 t.
•Brett Martin Plumbing and Drainage
Kijlstra Delivers First
To Welsh Water
Principal contractor Morgan Sindall choose Kijlstra’s
precast option for Welsh Water project and has installed
the first combined sewer overflow (CSO) chamber for
Welsh Water on a site in Maesteg, south Wales.
The 3.5 m long, 2 m wide and 2.1 m deep precast
concrete chamber was installed as part of Morgan
Sindall’s AMP6 framework contract with Welsh Water.
The works involved installation of the new precast
CSO chamber plus mechanical screen and associate
pipelines and manholes. The 17 tonne CSO chamber
was manufactured off-site and installed using a 60 tonne
capacity mobile crane.
This was followed by the two tonne internal weir
wall, grouted in place once the chamber had been po-
sitioned within its excavation.
The CSO riser unit, weighing another seven tonnes,
was then lifted into place on top of the base unit.
Preparation works in advance of the chamber’s de-
livery included construction of a 5 m x 4 m x 3 m coffer-
dam and a concrete blinding slab.
Morgan Sindall’s site agent Mark Thomas said the
precast option was chosen after careful consideration
of all the alternatives.
“We basically had three options - in-situ
concrete, a plastic chamber or precast. Precast
was the way forward for a number of reasons.”
Morgan Sindall chose the precast option to eliminate
and minimise risks associated with a traditional in-situ
pour - including working at height, steel fixing, manual
handling and concrete works.
As well as the health and safety benefits, the precast
option also saved time on the overall programme, effec-
tively reducing the 12 days required for in-situ concrete
to just one day to install Kijlstra’s factory-finished
Contractors World UK Ireland Vol 6 No 2