Project: Hempstead Valley Shopping Centre, Kent
Area: 800 m²
Completion Date: 2008
Contractor: Breyer Group plc, Romford
Surveyors: Donaldson LLP, London
System: Profiles system
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The old roof at Hempstead Valley Shopping Centre in Kent was inverted with single-ply membrane and ballast. It was in desperate need of repair, with tears and splits to the membrane, causing water to ingress into the buildings below. Foliage was blocking outlets and one outlet had deteriorated so badly that sections had been capped off, severely reducing the roof’s drainage capacity.
Existing services support consisted of metal angles, welded in situ, which had rusted, causing cable trays and gas pipes to sag dangerously. Access was a problem and there were limited places for delivery vehicles to stop and what deliveries there were had to be timed, and materials had to be carried up and over the building onto the roof using a rope and wheel. A noisy works restriction also meant the Breyer team had to begin work early and stay late to carry out such work, as the centre had to remain open.
Breyer’s works involved removing the ballast and slabs and stripping the existing membrane back to the substrate. This was done by hand without the use of a chute or hoist facilities and around the air-handling units that had to be left in situ.
The Profiles torch-on roofing system was specified with Thermazone tapered insulation to improve the falls for drainage. The capped off roof outlet had to be replaced when the shopping centre was closed which meant the Breyer team had to work from 9pm to midnight to install a complete downpipe section. This was made even more awkward because the area below was a home appliance store full of expensive white goods. These all had to be removed from the area or covered to allow the work to be carried out.
The plant supports had to be installed at the beginning of the works to secure the situation and were systematically removed and reinstated between each element of the roofing works – they were supporting not only a cable tray but also a very large gas pipe, which could not be allowed to sag for fear of fracture or gas leak.
New Roofgard outlets were installed along with new plant supports for cable trays and gas pipes.
The client was extremely happy with the quality of the works carried out and the fact that the scheme ran so smoothly despite the difficulties encountered.