Green RoofApril 30, 2009
I first heard about green roofs a while back, but I got very interested when Felder Rushing talked about the green roof he was going to put on his arbor. It is installed now and he has pictures of it up on his site.
I saw Majora Carter’s Ted talk in which she mentioned green roof projects in the south Bronx. The company, Sustainable South Bronx is working to green the area and green roofs is one strong component of their mission.
I think a lot of people have known about green roofs for a while, but the media coverage of them is increasing. This month, National Geographic has a story about green roofs. They have wonderful pictures of green roofs in Chicago, Manhattan, and Michigan. They also have pictures of green roofs in London, Canada, and Germany. The pictures are stunning, as most pics in National Geographic are. What I enjoyed most about the article is the clear explanation of what makes a green roof.
A green roof has many layers. At the bottom is the waterproof membrane that separates the living roof from the building. Above that is a root barrier, then a storage layer where the extra water is held until the next rain. next is a filter fabric then the growing medium. Regular soil would be to heavy, so instead it is a soil composite. Lastly, are the plants. The advantages of a green roof are beauty, lessening or preventing water run off, lowering roof temperature and inside building temperature, improving air quality, job creation in the areas of installing and maintaining the roofs, and urban gardening. A green roof can support a wide variety of plant life from landscape plants to fruits and vegetables.
In urban areas, traditional roofs absorb sunlight, causing the buildings to heat up. During a rainstorm, water runs off, overwhelming sewer systems and water treatment facilities. They are ugly and add nothing positive to the environment. Green roofs are a solution to these problems. While many grow plants that are for appearance and water absorption purposes, more and more food plants are part of the mix. Green roofs are a fascinating change in urban environments. I cannot wait to see more news on them as the trend continues.