I watch P. Allen Smith especially when there's chickens on his show or his Farm raised show on youtube. He has done a couple of shows from the city where the folks there show their roof top gardens. If you get a chance to see them its neat. I also seen in Grit and Mother earth news, where they just take the plastic pans (like 1' by 1'and a half) that the starter packs come in and place them on top of their sheds or chicken coops. They just said that don't put it where the sun is harsh and water frequent due to drainage. It was for sprouts, starting plants, and just a way to cool your rooftop.