greenhouse from portable shed kit?

Discussion in 'Homesteading Questions' started by flutemandolin, Jan 4, 2005.

  1. flutemandolin

    flutemandolin mark an eight, dude!

    Messages:
    721
    Joined:
    Aug 13, 2003
    Location:
    MN
    I have a portable 12 x 20 shed kit (tarp covered, Quonset style) that has never been put together. My husband and I were thinking of making a greenhouse out of it, just buy enough plastic to cover it instead of putting the tarp on it. Has anyone ever done this? Any ideas on how to attach the plastic to the 1 1/2 inch diameter pipe frame?
     
  2. fordson major

    fordson major construction and Garden b Supporter

    Messages:
    7,380
    Joined:
    Jul 12, 2003
    Location:
    east ont canada
    great idea! you could buy z bar and lock it like a green house but my self would get some 1x3 strapping bolt on the end frame and along the bottem strech the plastic in then nail another piece over the top. my bro and i have considered that and are looking for a frame
     

  3. mtnhighgirl

    mtnhighgirl Well-Known Member

    Messages:
    299
    Joined:
    Apr 26, 2003
    Location:
    a mountain in BC Canada
    We're trying this too. My hubby got one for free through work. Currently it is housing our firewood, but in the spring it will be a green house. We attached plastic to the sides using plastic ties wrapped around the poles. So far it is holding up against the weather.
     
  4. moonwolf

    moonwolf Well-Known Member

    Messages:
    7,576
    Joined:
    Sep 19, 2004
    Location:
    Canada
    Maybe here's another idea. Keep your shed with a good roof for storage and add the greenhouse to the side as a lean-to. That way you have the best of both situations. When I started, there was an old shed about the same size, so I framed up about an 8 x 12 lean to and covered with clear sheeting for the greenhouse. A wall heater that was installed was plugged into the shed that had an outlet, thus was able to heat the greenhouse if needed.
     
  5. Valmai

    Valmai Well-Known Member

    Messages:
    363
    Joined:
    Sep 29, 2004
    Location:
    Land of the Long White Cloud
    OR Mark out the area for the frame. Dig a trench at least 30cm all around the outside of your mark excluding where the door will be. Erect the frame. Buy your plastic large enough to fit into the trench (be generous with your measurements), then backfill the trench. I did that with mine, using rigid plastic tube for the frame and 120km howling winds didnt blow it down.
     
  6. whiterock

    whiterock Well-Known Member Supporter

    Messages:
    3,779
    Joined:
    Mar 26, 2003
    Location:
    South of DFW,TX zone 8a
    wrap it with poultry netting rough side in. cover with plastic. wrap with poultry nettin rough side out.
     
  7. Sylvia

    Sylvia Well-Known Member

    Messages:
    87
    Joined:
    Dec 1, 2004
    Location:
    PA
    Wow did a search just yesterday and I just know I came across plans for what your wanting to do BUT CAN I FIND IT NOW?!?!

    Maybe you'll get lucky here's a site that has 23 site links ---maybe you'll get lucky!

    http://theurbanrancher.tamu.edu/cottage/greenhouse.html


    Gosh, now I just know its on the web someplace!!!!!!
    :eek:

    Sylvia
     
  8. whiterock

    whiterock Well-Known Member Supporter

    Messages:
    3,779
    Joined:
    Mar 26, 2003
    Location:
    South of DFW,TX zone 8a
  9. mtman

    mtman Well-Known Member

    Messages:
    2,260
    Joined:
    Sep 2, 2004
    Location:
    AR
    they make clips for plastic the same as old garter clips they hold real good you can find them in a mariner store use them for tarps on boats
     
  10. 3girls

    3girls Well-Known Member

    Messages:
    510
    Joined:
    Aug 18, 2004
    Location:
    SE PA, zone 6b
    I have bought three 10 x 20 canopies from Costco. One is actually used for storage.

    The other two were put up together, sacrificing a couple ends, and I ended up with a frame structure 10 x 47. Along both sides, we installed 2 x 4 from one end to the other, just below the bend from vertical. On top of this and across both ends, we installed wiggle-wire base. I bought the plastic (and w-wire) from Griffin. I got UV protected 6 mil plastic and installed two layers. It went from ground to ground, but was attached with the wiggle wire. I assembled PVC rods for each side, attached it with duct tape to the side plastic hanging down. In spring, I will fashion handles and be able to roll up the sides. The ends have doors made from 2 x 4's. Various forms of hardware, all found in HD, were used to attach the wood to the steel frame. Primary among these were "U" bolts, bolted right thru the wood and ringing around the steel. Still to be done is to install a blower designed for this purpose to separate the two layers of plastic on the top.

    Inside, I have a 3 x 12' heated bench, some unheated benches, a small potting bench along one wall. The other wall is a 5' wide in ground bed. I also will have the mechanics for the various mist beds and a water faucet. There will be elec in there also.

    I will experiment using my chickens and rabbits for winter heating.

    I will try to provide pix one of these days. I think it turned out just fine. It will do very well for my current needs. My next one will be one of the big hoophouses.
     
  11. Windy in Kansas

    Windy in Kansas In Remembrance

    Messages:
    11,076
    Joined:
    Jun 16, 2002
    Location:
    South Central Kansas
    About time I tossed in--my two cents worth

    flutemandolin, I see that your location is Minnesota. How do you propose to heat this unit? Unless you propose to heat it with wood I would abandon a single layer of plastic idea as being too costly. Two layers of plastic well sealed at the edges would be much better, with air pumped between them so as to create an insulating layer of air.

    With the frame up remove any sharp protrusions or edges that might puncture the plastic. On the inside of the frame afix a small chunk of plywood to which a small blower will be attached. A small hole will have to be in the wood for the air to be blown through.

    If the frame has wood around the bottom edges that is great, otherwise apply some so that the bottom edges of the plastic can be attached.

    For simplicity I would cover the ends solid rather than trying to figure a way to apply a double wall of plastic. They should be of insulative material.

    Once the blower is in place, place the first layer of plastic over the unit. Fasten this layer only to the plywood that the blower is attached to. Cut a hole for the blower air to blow through. Lay the second layer of plastic over the first.

    With both sheets in the position you want them secure the bottom edge of one side with furring stips or other solid material SCREWED to the bottom perimeter. I've not heard the term "strapping bolt" but suspect it might be thin metal strips which would also work well. Apply the strips abutting each other to prevent air leaks between the ends.

    On the second side DO NOT STRETCH the plastic layers tight. The air will inflate it to take out the slack. To a point, the air will inflate between the layers much like a beach ball. That is the reason you want SOME slack, but not too much. (On the greenhouses I helped re-skin when air was applied the layer between the plastic was about 12 inches.) Secure the bottom edge of this side, again with furring strips, strapping, etc.

    Secure the ends next, fastening the end with the blower first. You don't want to pull the plastic away from where it is fastened to the blower holder.

    When the plastic is secured at all bottom edges and end edges the blower can be turned on. The type of blower used looks much like an auto defroster. There should be an adjustable throttle plate on the output so that you can limit the amount of air it blows into the layers of plastic. Otherwise you might over inflate them and burst one of them or force the plastic apart where it is fastened. That is why you use screws, not nails. There are clips designed to hold the plastic, but I have seen them fail often, much better to use screws and be certain.

    With the unit properly inflated the plastic will be taut so that the plastic cannnot blow in the wind. Usually when you slap the inflated side it has kind of a ringing sound as the slap vibration goes from end to end of the unit. With the tight plastic the snow will pretty much slide off.

    To make sure I've presented this correctly, once inflated the first layer of plastic will be blown toward the inside of the greenhouse, while the outer layer goes away from the first. Again, make sure there are no sharp protrusions that this inner layer will puncture on when inflated. The whole thing kind of looks like bubble wrap as air forces the plastic around frame members.

    The blowers take little electricity since they are such small units. Once inflated, which can take a half hour or more for the initial inflation, it takes little to keep the plastic taut. Adjust the throttle plate to keep just enough going in to keep it taut as no more is needed.

    While I didn't mention putting a well sealed door into one end, I assume you figured that out. Better would be to make an entry room with two doors.

    Questions? I'll try to check in from time to time.
     
  12. Cornhusker

    Cornhusker Unapologetically me Supporter

    Messages:
    16,262
    Joined:
    Mar 20, 2003
  13. flutemandolin

    flutemandolin mark an eight, dude!

    Messages:
    721
    Joined:
    Aug 13, 2003
    Location:
    MN
    Thanks for all of the ideas! I'll have to print this out and show it to dh.

    Our plan for this greenhouse would be mainly to use it as a season extender, as in Eliot Coleman's Four Season Harvest, with row covers within the greenhouse for added protection. I'm not planning on using any supplemental heat, although the idea of putting a double layer of plastic and blowing air in for insulation sounds intriguing.

    I have also considered a cattle panel hoop house, although that might be an entirely separate project.