Creation of a green roof on a 20 foot shipping container that will retain water during heavy rainfall events. This green roof was created on a Shipping container in Mytholmroyd June 2019
1) Clean and de-rust the roof.
2) Seal with bitumen and cover with heavy duty DPM.
3) Construct wooden frame around edge of the roof, ours is 225mm high made from decking timber on the outside and bitumen coated battening timber on the inside. Our design isn’t attached to the container so tie-ins have been used (tying the opposing sides of the frame together). All gaps in the structure were filled with silicone then everything painted with bitumen.
4) Line the structure with heavy duty DPM, seal all edges.
5) Cut holes at the bottom of one side of the frame to drain excess water, this goes into guttering that feeds into a water tank.
6) Place 50mm of gravel on the roof, cover with weed suppressant membrane, fill to top with soil and plant.
7) Install the guttering. Excess water can be collected in water-butts/tanks that drain slowly.
Benefits and constraints: None of us had done this before so it was a learning curve but all has gone well.
We used approx 1.5 tonnes of gravel and 5 tonnes of soil, to prevent the roof bowing under the weight it has been internally supported (with acro-props initially then a substantial timber frame).
At saturation point the soil will retain about 1,800kg of water or the equivalent of 63mm of rainfall (a more accurate figure will be determined by tests to be conducted shortly).
Further opportunities: The quantity of soil can be varied to suit, additional water-butts or water-tanks can be incorporated.
Costs: Approximately £1,000.
Soil – £300, plants – £200, water collection and storage – £200, timber – £150, gravel – £120, other items – £50,
Who?: Mytholmroyd Flood Wardens
Contact email: email@example.com