green roof! advice?

[benjo]

hi all!

i'm thinking about putting a green roof on top of my coop, but i'm having a hard time finding any specs or basic guides to building one.

here's what i've surmised (correctly or incorrectly):

1. the roof should be at a slight angle to assist in drainage.
2. there should be something waterproof between the soil and the roof (especially since i'll likely be using wood)

that's about all i can find.

i'm sure somebody on here has one. sorry if this is a duplicate topic. here's some question i had:

1. what makes a good waterproofing material? will plastic garbage bags work?
2. how slight/severe should the tilt be to allow for good drainage? should i drill holes at the end where drainage is to occur?
3. if i'm using plywood, will 3/4" cut it? if i support
4. my coop is roughly 4' by 6', with corners being 4x4 posts and 2x4s and 2x6s running between them. will that be enough support from the ground?

any advice would be much appreciated!

-b

 

[Chieftain]

...

 

[patandchickens]

I would strongly recommend reading one, or preferably several, of the books written about constructing green-roofed buildings and sheds. (There are a bunch). As you have guessed, there is a lot more to making it work than just slappin' some plastic down on a slightly-slanty roof and laying turf on.

It is for sure doable, but in order to avoid having to UNdo it in a few months or years when it self-destructs or damages the rest of the structure, it is really worth doing all the details right. There are various schools of thought of course but any of them is for sure better than winging it

One warning: in most climates, it is not going to be a "green" roof unless you water it regularly (which IMHO is a profligate waste of water). It will be a "brown" roof much of the year. Using succulents such as sedums will decrease the extent to which it looks bad, but still, don't be imagining a grassy green lawn or meadow up there, b/c most of the year, it won't be

Good luck, have fun,

Pat

 

[DarkWolf]

Quote:
At least a 1/12 pitch.

Quote:
Here are the layers that the "pros" use. You can get away with less.

Quote:
No... It will not.

You'll be well off with at LEAST a layer of well overlapped 30# felt paper to start and then something over that. The BEST thing to use would be EPDM. You COULD get away with a layer of rolled roofing.. Basically shingle material with the grit on it, but in a large roll. Glue down.

Quote:
A 1/12 pitch minimum.. 2/12 would be better since you're most likely NOT using EPDM or any solid surface roofing underlayment.

Quote:
Sure.. Just make sure you're using good rafters.. 2x6 min, depending on your span. Last thing you want is several hundred pounds of growing media collapsing on your head.

Quote:
Not sure, depends on how it's laid out.. Hard to visualize via your description.

Quote:
Do more research.

I'm assuming you'll be growing stonecrop such as my fave, graveyard moss and other succulents? They will need to be highly drought tolerant.

Growing medium is typically a mixture of compost, some sand and a whole lot of perlite or vermiculite to keep the weight down. Some peat moss can be used to retain water. Pre soak it first, else it will never absorb anything.

Some inspiration:

http://www.livingroofsinc.com/our_work/

http://www.digginfood.com/2009/03/backyard-chickens-101-cool-chicken-coops/

http://home.centurytel.net/thecitychicken/hhotm.html

Forgot this one, which is right here in BYC.

https://www.backyardchickens.com/web/viewblog.php?id=7019

 

[benjo]

thanks, guys! i was planning on super-drought/heat tolerant succulents - lots of that kind of stuff available here in arizona. i'm more interested in the cooling properties than the decorative aspect.

 

[DarkWolf]

Ah... Well.. Then even a simple layer of pine bark mulch would do you well.. It'd be the air space between the particles that allow the underside of the roof to remain cool.

 

[CityChook]

wow, thanks for the info Darkwolf! Love the inspiration photos!

 

[sune42]

I have a book called Building Green that has a lot of information on living roofs. You could probably find it at the library too. This was my original thought for the coop roof, to grow lots of herbs specifically mint to deter mice. However, after seeing Chieftain's water collecting system, I am thinking that might be a better way to go.