Project Description
The iconic Leeds RERF (Recycling and Energy Recovery Facility) is the flagship development at the heart of Leeds Integrated Waste Strategy for the next 25 years. The energy from waste plant is designed to treat the 214,000 tonnes of household waste generated in Leeds each year. The landmark 42m high glulam timber framed building (the largest timber framed building in the UK and the largest green wall in Europe) that houses the incinerator was shortlisted for a RIBA 2016 award. The associated domed timber roofed structure used to store the incinerator bottom ash has a green roof finish and was a finalist in the 2016 UK Roofing awards.
The Challenge
ABG were asked for a solution to cover the domed facility with a green roof to create an attractive, low maintenance system on a steep, light weight domed structure. For plants to grow successfully, the right environment needs to be created. Plants need stable soil conditions, light, moisture and nutrients and to hold sufficient growing media in onto a steep slope requires a surface retention system that is structurally strong enough to prevent the whole mattress from sliding off the smooth roof.
The Solution
The ABG Erosaweb geocell was the ideal solution to retain pockets of the growing media over the whole surface and prevent soil movement. The smooth surface of the dome meant that the ABG Erosaweb geocell needed to be reinforced by tying it to an ABG geogrid, suspended in sheets from a carefully positioned anchor point using sealed bolts into the roof structure, through the waterproofing membrane. The ABG Installs team placed a layer of ABG Roofdrain under the soil retention system to drain excess rainwater away, whilst doubling up as a reservoir board to retain irrigation water. For the steeper parts of the slope, an additional DF irrigation hose system was installed to prevent drying out in hot conditions. The green roof, combined with Europe’s largest artificial living wall, provided a biodiverse and aesthetically pleasing finish to this facility.
The ABG Service
ABG provided a turnkey solution for this part of the project, which was a particularly difficult dome shaped green roof, taking it from design through to installation. The whole project was finished 3 months ahead of schedule.
