The key technical elements in a green roof are loading and root/water proofing. Luckily for us, the roof that Blackwells used to fill the space between the original Victorian structures was made from large rolled steel joints mounted on reinforced concrete piers. A structural engineer calculated that it was strong enough to take 30cm of substrate plus hardlandscaping, plants and people. The drainage system was also easily adapted for the rainwater harvesting system.
Martin Mikhail, RISC's resident fixer, managed the various stages of the build. We employed contractors, MJ roofing, to repair the existing roof and install the elements required for a green roof. The skylights were raised to accomodate 30cm of soil and three layers of special bitumen felt, impregnated with a herbicide to prevent penetration by plant rootlets, were laid on a base of marine ply. A layer of polysterene insulation was then put down (although soil will provide good insulation when dry, it conducts heat when wet), followed by a plastic drainage/reservoir layer which allows water percolating through the substrate to flow towards the outlets and into the rainwater harvesting system. The lightweight substrate was placed on the roof by a forklift truck and spread by hand.
Our builder, Steve Hunter, took care of the hardlandscaping – laying walls and paths, and putting up the hazel fencing. Local fabricators made the staircase and railings, and Jessica Witchell, another RISC worker, coordinated a team of volunteers to implement the original planting. The wind turbine and photo-voltaic panels (inherited from Caverham Court Environment Centre) were installed by Ernest Warren of Hitech Energy and subsequently reconfigured by another volunteer, Stephen Loundes.
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What's Global Citizenship Got to do with The Olympics? 16:00 until 18:00 on Thursday 23rd February 2012 Move beyond the flags and anthems! Sign up for this participatory workshop for primary and s... |
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Global Citizenship from the Margins to the Mainstream 10:00 until 16:00 on Thursday 8th March 2012 at RISC, 35-39 London Street, Reading, RG1 4PS Cost: £60 inc VAT Hear Lucy Siegle, k... |
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