Blue roof installation at Rathbone Market, London
Geogreen installed the ABG blueroof system for an extensive green roof project in London.
Project Information
Client: English Cities Fund (ECf)
Contractor: Geogreen Solutions / John Sisk & Son
Consultant: Churchman Landscapes Architects
Product: ABG blueroof System
Quantity: 850m²
Benefits:
- Experienced blue roof installation team
- Versatile to allow multiple finishes
- Fitted in tight working environment
- ABG blueroof eliminated the need for attenuation tanks at ground level
- Installed directly on to Hot Melt Roof
- Geogreen service: installation with ABG design back-up
Project Description
Owners ECf entered into an agreement with landowner Newham Council to deliver a sustainable and mixed-use community at Rathbone Market.
The new community development included 652 homes with shops and public landscaped amenity squares to produce a pleasant living environment. Facilities include public walkways and ornamental ponds at podium level, and an allotment for residents to develop at roof level.
The Challenge
The designer obtained consent under the latest SuDS regulations in this densely built area of London.
Restrictions on outflow rates to sewers from the building demanded high attenuation capacity. The original design for attenuating water following a storm event involved discharging to tanks buried under the ground. In addition to this being an expensive method, construction space at ground level was at a premium. Buried tanks would not only take up valuable space, but would also interfere with below ground services. It was determined an alternative solution was required.
Solution
Geogreen Solutions worked with ABG Geosynthetics to introduce the idea of utilising the flat roof space available. For any alternative solution to be considered it would have to take into account the storage/discharge requirements, restrictions on parapet threshold heights and BREEAM requirements for biodiversity enhancement. Geogreen proposed the ABG blueroof system, which could be installed directly on top of the hot melt waterproofing and accommodate the range of surface finishes required. ABG blueroof utilises the roof construction for the attenuation of storm water, releasing it at a controlled rate in the period following the storm. The parapet thresholds meant storage limitations at high roof levels. Geogreen’s ABG blueroof solution was a cascading system from high to low level roofs, with each level having its own bespoke blue roof. These systems varied in depth from 25mm (high levels) to 120mm systems (low level). Finishes on the seven roof areas included public paved access and landscaped areas, ballasting used under maintenance areas and biodiverse areas used to attract wildlife. This also increased potential for BREEAM points. Space to construct the system in most of the roof areas was very restricted and the ABG blueroof system needed to be cut and fitted to shape. As the main contractor, Geogreen Solutions installed the system to suit the many architectural features and penetrations through the roof.
