Greenroof project at the Extension

The Cooperative Extension agent had been wanting to do this project for some time and asked me to research it and see if it would be a feasable addition to the Display Gardens that the Master Gardeners design and maintain. I think I got the project because we had an earth shelter house for twenty years. I had quite a problem at first even finding anything on the internet because we were not using the name Greenroof. I searched roof gardens and sod houses and a dozen other possibilities until someone on another site suggested I look at greenroofs and finally I was able to make some progress. They reduce the affect of buildings and parking lots on drainage or runoff and the buildup of heat in urban areas, in particular, which add to the expense of heating and cooling. The idea is much more common in Europe than here in the USA, but the idea is being tried in various parts of the country by businesses like Ford and co-op comunities. In brief the building roof ,which must have appropriate reinforcment, is covered with an impervious membrane which is boxed in, growing medium spread and secured and then is planted with a variety of plants that suit the location. In our case we are using mostly members of the sedum family. A major amount of info was gleaned from a site from the University of Pennsylvania which built several to test out the heat reduction claims. You can see their results here: http://hortweb.cas.psu.edu/research/greenroofcenter/research.html Another good site from a business selling perlite http://www.schundler.com/greenroofs.htm There are many other sites that provided good and sometimes bad info but I always say even negative experience gives data. I even saw a greenroof at Epcot Center in Florida. After collecting about 300 pages of info and 50+ pictures and a 20 page list of plants that have been used I began putting together a plan for our little garden shed.
The first step was to reinforce the shed which had never been built with the idea of carrying the weight of a 2x4frame that would retain a planting bed that would cover the entire roof. The roof had to be stripped of shingles and covered with 45M. rubber EPDM.That is used on roofs and as pond liner. The roof sloped rather steeply so a system of bumpers had to be used to prevent shifting of the perlite and soiless mix that would be the planting medium, Against the EPDM there is a layer of capillary cloth to prevent the draining of all moisture to the bottom of the slope and that and the bumpers are covered with a layer of landscaping cloth. Tomorrow I will use my leaf vac to spead the planting medium amd that will be covered with plastic fencing and the plants will go in the holes in the fencing. There is a drain at the bottom to keep the planting mix from being washed out. I have discovered I am not cut out to be a contractor. While I know exactly what needs to be done and how to do it and why, I'm not very good at telling other people how to do it. Jessamine

I am very interested in hearing your results!

I just Googled greenroof and it's amazing the things they do with them. I just wouldn't want to have to weed my roof, too.

thanks Jessamine. Sounds like you really researched this project!

Good info at those links.