Making Green Houses
Here is an awesome DIY hoop green house building tutorial.
How to Build A 300 Square Foot Windproof Hoop House For Under $500. from Natural Living Ideas. (Thanks Time2Help who posted this on facebook.)
This is a 12′ x 24′ x 6’8″ size.
A frame is made of pressure treated lumber. (A center frame/brace is made to strengthen it against wind.)
Rebar is hammered into the ground just inside the edges of the frame and 20′ long 3/4″ PVC pipe is bent into a semicircle and put on the rebar anchor points. This makes the hoops.
Plastic and shade cloth are applied.
I would love to see other’s green house efforts and what designs and plans others are using.
We have 6! Love them and think everyone should have one.
Our first two were PVC and we had issues with the greenhouse film interacting and being degraded by the PVC. The first few times we skinned it was with painters film from the local big box. There is no ultra violet inhibitors in the stuff, it broke down within a couple of months. We skinned those first high tunnels three times in the first year. Greenhouse film and steel hoops will save you money in the long run.
You need a high tunnel! Google "johnny's high tunnel pdf" for a GREAT tutorial.
Johnny's Seeds has an instruction manual that Rob was just referring too.
Lots of good pictures and instructions.
The frame is build with the ubiquitously available 1-3/8" bar commonly used along the top of chain-link fences
Johnny's Seeds sells a bending tool (a "bender") for the purpose of creating the large steel hoops.
I have a hard time posting links, don't know if it is me or my browser….
That is the one, great info there.
If you do go with pvc, be sure to prime and paint it. It won't last as long as steel and will not be as resistant to wind or snow, but it will work!
Sand_puppy and Robshelper,
Thanks for finding and sharing those resources on tunnel construction. I currently don't have the space on my property to build a low tunnel but these resources will come in handy for when I do. Eliot Coleman has a pretty good video on how to build cheap tunnels that aren't frame in or anything https://youtu.be/ovR-OZlul3w?t=11m29s. I definitely like the Johnnyseeds tunnels better, but for putting one up in the fall and taking down in the spring, this Eliot Coleman one looks pretty easy but it would be nice to have a door on one end.
Earlier this year, I constructed a chicken tractor off of plans I got via the University of Kentucky Cooperative Extension that used two 50″ x 16′ feedlot panels for the arch skeleton. Basically it was just building a frame for the bottom, arching the feedlot panels so they would fit inside both sides of the frame, securing the panels, and framing out the back supports and front doorway. The most tedious part of it was attaching the poultry wire to the outside of the tractor.
It occurred to me that it would be incredibly easy to make a high tunnel with the same strategy — just adding more feedlot panels end-to-end to achieve the length desired, and bracing the frame against outward pressure every 4′ or so.
Here’s a link to the UK chicken tractor plans for anyone looking to do something similar.
For me, my plan for a high tunnel is 1/2″ electrical conduit, embedded into 2x4s on the ends. place the plastic over the ec, and then snap pool noodles over the EC/plastic, and fasten with ties. this holds the plastic to the inside of the pool noodle. then wrap the plasic around the end of the 2×2, and loop it back. the pool noodle now holds the plastic to the outside of the curve, creating a double wall airspace. For extra insulation beyond that, fill with foam peanuts, straw, grass cuttings, or other loose, cheap insulation.
Roll the ends, fasten with zip ties. then screw or bolt the 2x2s together for a strong double-wall (and maybe insulated) high tunnel.
My big conclusion from building a 5′ high squirrel defense cages over raised beds is that when I can’t stand up fully inside the enclosure it becomes an ordeal to enter and work there. I quickly find other things to do and let the weeds grow.
Conclusion: A green house must be tall enough to stand up inside. Or possibly, like a low tunnel, small enough to reach from the outside when the plastic is rolled away.
Unfortunately, I still don’t know how to upload pictures here; but you can see my idea of a greenhouse on my facebook site, now. If anyone wants to import the pictures, please be my guest: I give permission.
Here you can see the double wall. The inner layer of plastic is held to the inside of slit pool noodles, which are themselves clamped around the 1/2" electrical conduit by zip ties. Once the noodles are all locked in place, 2x2s have 5/8 holes drilled halfway in to recieve the electrical conduit; and set screws hold it together. The plastic is allowed to overlap everything by 9". It is then wrapped around the 2x2s, and the edges rolled, to make a double wall.
There are 4 sections here: 2 half-high walls, and 2 5' roof arches. Once the sections are complete, the 2x2s are scabbed together with short pieces of 2×4 and screws. Finally, we built triangulation: an A-shapped support in back, and a delta-shaped support in front, screwing the triangulation to the ends of the 2x2s.
We next drove EC into the ground as stakes, and screwed it to the frame to hold everything down during wind storms.
What you see here is before the A shaped ends were installed.
If you're in an area that gets really cold, like Colorado, I'd suggest putting dry leaves between the plastic layers as additional insulation. You can also do like I will, and either put an incandescent lamp inside, or put a warm air vaporizer in there. The vaporizer seems to work really well, in my experience.
By the way… the pretty little shed in the background, we built out of junk 5' x 5' pallets. That was a fun project too. You can see the construction process for the shed over at my facebook site:
Doing that without a traditional motor vehicle was interesting. One of the pictures shows an electric-assist bike, with detachable dolly, for bringing the siding home. Fun, fun, fun.