Gonmon's DIY Greenhouse Plans

[fotofashion]

When DH designed my present GH, he did not consult with me so he built it like your solar design. I absolutely HATE it. It is a big waste of space. When I lived up north (In MI) my GH was a conventional shape. The walls were about 5 or 6' high. We covered it with fibreglass panels and double insulated it with sheet plastic (no polycarbonate then) eventually heated it with natural gas. I had benches made of 2x4's with hardware cloth. Pass 20+ years and an altogether different climate-Texas Gulf Coast. And--the "solar" shape GH. The trouble is that the sloping north side wastes space. I like to hang as many plants as I can. My benches now consist of the plastic shelves you can buy at any "big box" store. They aren't too deep so I can reach my plants easily. What I really need is a new GH that is a bit bigger. My present one is 12' x 16'.
Anyhow, my point is that you need to consider how the shape of the GH will restrict or extend the capacity.
I find that treated 2x4's are adequate for the structure (even in MI where we had a lot of snow).
I have 3 reinforcing rods that run back to front up high to hang plants from in addition to the benches. My ventilation system consists of an intake shutter down low near the ground at the end opposite the door and an outlet shutter + fan above the door controlled by a temperature control and a large box fan that runs 24/7. Even so the temps get up to 115 + sometimes.
I hope my rambles give you something to think about and I hope that eventually you get the GH you need and deserve.
Beverly A.

[Gonmon]

Originally Posted by fotofashion

When DH designed my present GH, he did not consult with me so he built it like your solar design. I absolutely HATE it. It is a big waste of space. ....The trouble is that the sloping north side wastes space. I like to hang as many plants as I can. ...Anyhow, my point is that you need to consider how the shape of the GH will restrict or extend the capacity.
I find that treated 2x4's are adequate for the structure (even in MI where we had a lot of snow).
Beverly A.

Thanks for your info Beverly. I went into my sketchup and measuring from the midpoint of the South bench, the roof is only 2 feet up.... Which is a bit short for anything buy seedling flats maybe. Did you mean that the sloped South side wastes space? In my plan the steeper side faces South, the North side extends 4.5 feet above the benches before sloping. I too like to hang my plants in baskets or mounts. Since I want to breed stanhopea relatives and miniature other stuff, I want as much basket/mounting space as I can get.

I wonder how much more heat the a Solar South side adds over a convential shape... If I raised the South wall just 2 feet over bench height it would give a lot more vertical grow space on that South bench. I'll have to go play around more and see if that's an option.

I use 2x6's for the supporting members so I can fit 6" thick insulation versus 4". If I remember right 4" fiberglass bats are 14 or 15 R-value, while 6" are 20. I want to conserve heat as much as I can because with my weather that is going to be the biggest operating cost. The cost of building with 2x6's vs 2x4's is small enough that it will pay for itself in a year or two.

I'm also rethinking the benches too. If I bought/built shelves like a lot of people here use, that adds a grow space I can use for lower light plants. I guess it's a tradeoff of water storage for heat savings, or more plants. That's not really a hard choice is it?

[fotofashion]

In my GH the north side is sloped and that, of course, is the space waster. The south side wall is about 5' high. I can hang plants all the way down the rafters to the wall and still have room on the benches. The peak is probably about 10' +. I have to use a short ladder to hang the plants from the re rods.
Here, the winters are relatively mild so a couple of electric heaters do the job on cold nights. It has gotten down to around 32 inside, especially last winter when we had a really cold one. But even Phals were not harmed.
As an aside, in MI when we first built the GH, it was covered with polyethelene. It used to keep me awake nights snapping up and down with the winds and me thinking that it was about to tear. Never did though. The next winter we had the fibreglass panels.
I understand your concern about space vs. economizing on the heating costs. Are you considering buying the polycarbonate panels that will give you the maximum insulating value? I know they are more expensive but if they will lessen your heating costs it would be worthwhile to consider them.
Winter is not that far away for you. You need to get cracking on your new GH so you won't get caught building it while it is snowing.
Beverly A.