Steven Kovacs wrote:Green roofs are wet and heavy. I suspect they can't really be done as cheaply as you like.
Can you use scrap metal for roofing? There are a lot of metal-roofed shanties in the world, which suggests it's a good frugal roof material.
What climate are you in? If it's warm enough there may be other natural roof options.
Travis Johnson wrote:Nice idea on the pallets.
One word of advice if I may, don't try to rip the pallets apart. They are made with ring shanked nails, driven by pneumatic nailers that have glue on the nails. It is far faster and easier to just use a reciprocating saw (sawzall) and cut the nails between the wooden joints. You also won't lose boards to broken slats.
Glenn Herbert wrote:Do you want the green roof for cheapness, or insulation? I suspect there are numerous materials that would be cheaper, and far easier to do on a 6:12 pitch. Metal may be the most durable, easy and lightweight option. That would allow your framing to be significantly lighter than a large green roof would require.
If you want insulation or thermal inertia, I think you would be better served by making the pitch flatter, which probably means the sidewalls would be higher if you are looking for loft storage. I doubt there is a good way to make a structural grid to hold a green roof on a 6:12 pitch without treated wood, unless you have access to black locust or one of the other highly rot-resistant woods.
For plastic as a membrane under a green roof, recycled vinyl billboard material can be gotten relatively cheaply. That is what the wofatis at Wheaton Labs are made with.
Mike Jay wrote:Sorry to ask this, but is your structure strong enough to hold up a living roof?
Mike Jay wrote:I'm not an expert but I'm guessing your 16-18" diameter poles are plenty big enough. Would they be going down underground or sitting on pads?
I think your ridge sounds fatter than in needs to be if it has supports every 8 feet. Same for the top plates. But bigger never hurt anyone (unless they fell on someone's foot).
The rafters may be undersized at 4". 6" sounds good to me.
Here's a possibly horrible idea. What about using pallets as the roof deck and purlins? If you had enough of the same size pallets, you could space your rafters to match the size of the pallets. Then you wouldn't need the 2x4 purlins and you could reduce the plywood to one layer or maybe even skip it altogether.
Are you sure you want all those support poles in the middle of your barn? Unless I'm misunderstanding, you'll have poles down the center and 1/4 of the way in from each side. They'd be on a 6' by 8' pattern so you couldn't fit a trailer or tractor in there very easily. I'd be tempted to find a way to space out the poles much farther (12-16') or have bigger rafters and no intermediate ridge poles.
But, like I said, I'm not an expert so take it for what it's worth
jared fink wrote:I did a quick search for recycled vinyl and I like this idea. Any advice or thread you can point me to about using them? Wonder if I should layer multiple sheets and how to seal overlapped joints...
I have plentiful access to ruff sawn cedar that I would use for a grid. Not sure on the spacing though or what material to use to prevent growth medium from flowing under.