I'm new to the forum. About 2 years ago I moved to Portland OR, from Salt Lake City Utah where I had built and mainted a couple of great square foot gardens.

We just moved into a new house as as much as I love the house, the backyard is small and largely shady. The other day, my partner had a great idea - GREEN ROOF. We have a mostly flat unattached garage at our house and with a few adjustments, and my building a good sturdy ladder, I'll be able to build a small green roof.

However, with that, I dont' want to actually plant onto my roof, I want to build the raised bed version of 4X4 garden and put them up on low stilts. Buildwise, it's not major - however, the weight is a concern. Does anyone know where I can source lightweight materials or kits to build the 4x4 bedframes? I would use the same kind as i would on the ground, I just don't want them to be made of wood as I think that's heavier.

Any info you guys can share would be great. I will post pictures as I get things going.

There doesn't seem to be a whole lot of action in this forum...

I can't say whether your garage/building is built strong enough for building and putting raised beds on!? But from my knowledge of having a one car flat roof garage many moons ago. I never gardened on it, but he is my 2 cents...

I myself wouldn't put raised beds on it, seems to me like alot of weight in one place all the time. If I was to utilize the roof I would go with a few containers ie 5 gallon buckets ( tomato's or peppers etc ) A) they can be moved around B) and or taken off if needed without disturbing your plants! The down side imh would be; A) Wind! would want to make sure your containers don't get blown over or OFF the roof and B) might want to put some kind of white ground clothe down to reflect the heat! That tar or asphalt shingle like to absorb heat and you might find yourself watering 3 or more times a day if you aren't using swc's.

Well that's my opinion.. goodluck to you ya if you procede with your 'green roof'.