Is a Green (Eco) Roof Possible?

[ClaudMonet]

After 5 years of eating good pizza using our unfinished, uninsulated oven, we have finally decided to finish the outside masonry. We thought we had the roof design nailed until I found a picture of a WFO in Norway with a green (Eco) roof. Eureka! Friends and husband poo-poo'd the idea saying it would get too hot up there to support plants. My plan is this:
finish the sides with 6" split fieldstone (there is cement board frame to build on)
Cover oven with 1" FB blanket
fill remaining open space with vermiculite (will be min 3" all around)
use heavy duty irons to build rafters for roof consisting of
2 layer cement board topped with 1" plywood
Surround top edges of roof with 5" NY bluestone rails and fasten
EPDM thick mil rubber roof.
Will the roof be too hot to support plant life?

[Les]

I believe one of the first builders here (Paul Ages) put a herb garden above his oven so it can be done. Insulation is amazing stuff

[david s]

With all that insulation on top there will be virtually no heat gett ing to your EPDM layer. You should however arrange some way of venting the insulation layer so moisture can escape as totally sealing the oven traps water in as well as keeping it out. Earth on top of the oven will also act as an excellent insulator. Will look forward to seeing what you do and how it performs.Maybe you can do a nice impressionist paint of your results.

[Archena]

Um, you do realize that whatever 'green' benefit you get from a live roof is cancelled out by the synthetics/materials/carbon footprint?

Okay, seriously, don't forget the drainage. The heat isn't going to be the problem with all that insulation but if you don't allow drainage you will either be planting water lilies or watching all your plants die. My guess is you should plan on extra feeding the first year since the soil will be at its least compact and will leach like crazy. Conversely, tomatoes like their 'feet' warm and I bet a cherry tomato vine (I know it's supposed to be an upright but mine all climb like vines) would do really well and be really pretty.

Best wishes!

[bluecrow]

Here is a link to a great build with a garden roof. (not mine)

http://www.fornobravo.com/forum/21/3...e-7878-49.html (36" in Seattle)

Don

[thickstrings]

I would be concerned about snow load ,being in WI. Not to mention spring melt off....

[Laku]

I'd be concerned about the roof getting dry and few unlucky sparks landing on the dry vegetation.

[ClaudMonet]

Love this site - thanks for your responses!

That's a relief we'll have plenty of insulation. The front of the roof will be 1" higher than the back, so hopefully it will drain (we'll leave an opening in the back 2 corners). The roof will be bolstered with angle iron to support the boards, epdm and potting soil so I'm sure it can handle a couple feet of snow. A stray spark will be fine - but I'll avoid planting pine trees up there Archena - I try hard to be green. I ride my bike to work most days, our house has solar hot water, we keep hens, I have a big veggie garden, I recycle. But I need to feed my pizza addiction, which unfortunately comes at a cost to the environment. Please don't tell Ed Begley Jr.

So my question is about venting out any moisture. Can I stick some pieces of copper pipe under the roofline (will be under the epdm "tray") and extend it into the box into the loose vermiculite? If so, how many, what size copper pipe (1/2," 1") how deep into the box and should each end have screening to keep bugs from going in and insulation from coming out?

[berryst]

I insulated mine and then buried the whole works. The only thing that shows is the front. The plants and drainage are not an issue they grow fine. At some point I expect the trees will start to get singed from the chimney heat/smoke. The unit works fine and there is no sign of aging at all....my homemade mortar has been successful.
chris