Greetings! I want to rip the asphalt shingles off of my garage roof and install a green roof. A lot of information is out there about putting green roofs on flat commercial buildings, but I'm not finding much residential, small-scale, diy how-tos. Has anybody out there done a green roof who might be able to offer advice? By the way, the garage was built in 1918 and is a hip roof, not terribly steep. Paige
Hi Paige, I have read alot about them, tho never built a green roof myself. There are some great books that deal with the issue, including one titled "Green Roofs"! (which I do not own, but looks interesting). I understand that they involve a layer of strong/heavy roofing material, generally made of EDPM, or some similar substance laid ontop of a roof. They are then covered with dirt and or plant matter. I have read of green roofs laid down with straw bale on top, which decayed and became soil. The main issues seem to be making a layer below the waterproof barrier that does not pucture the layer, (no loose nails or nail heads poking up), and strengthening the structure below because these roofs are HEAVY, especially with snow loads or with rain water. Most of the roofs I have heard of were designed to be earth sheltered, so you may want to look closely at your roofs design to see if you would want to add 100 psf to it, or get a carpenter or engineer friend to offer an opinion. Having a slight slope will be good as it gives somewhere for the water to go. We are going to build an earthbag house here that will enable us to keep material cost down, and I am thinking of a green roof to top it off as the soil offers sme incredible thermal advantages to us (humid lowland tropics). Two sites that might be of interest to you: https://www.greenroofs.com/ and https://www.greenroofs.com/ And, for roofing material, Firestone Pond Guard is made without algacide and fire retardent, so leaching of chemical nastiness from rainwater from your roof (an issue with many commercial EDPM barriers) is reduced or eliminated. Look at: https://www.pondliner.com/EPDM.htm Also: https://www.ecobusinesslinks.com/green_r ... design.htm If you build it, talk about it as I would love to hear from someone ho well it worked out and what problems you had building it as well as what benefits it offers you. Best, Christopher
Paige, Check Chuck Marsh's house in "The Good House Book", page 160. It offers lots of enthusiastic info, not much how to, tho. Daniel Chiras's book, "The Natural House" has lots of other info, too, but not much hands on.... Good luck, Christopher
hello, you don't have to buy expensive books, just look on the pages of the roof-material industry you'll find plenty of information. I don't know the australian brands, but normally the materials are either bitumen or PVC, sometimes there are other plastic materials. The most important thing is that the roof has to be perfectly leakproofed. If there is yet a bitumen layer you could put another layer onto it. The advantage of bitumen: environmental friendlier than PVC and there are always several layers. You can eve call or e-mail the producers that they can make you a suggestion how to built it up. The material you put on the roof should not be too heavy so instead of putting normal soil you put always a premixed substrate. The plants on the top should be extremely drought hardy. the temperature on a roof is much higher.
Thanks Christopher and Hedwig--I'll keep researching green roofs and in the meantime keep propagating sedum to grow on top. I did find a place that sells the soils used on green roofs, actually here in Massachusetts. Perhaps I should pay a visit and see what info I can glean. Maybe I'll get it together by springtime. Paige
