Green houses

[JeffW]

This was my first green house made from 6MIL plastic (painters plastic) and a car port framing (the kind you can buy that have the top canvas) they are 2 inch metal pipes that all fit together and then you put the top over it and it becomes nothing more than a simple covered port. However I left the cover off and instead I enclosed the frame with 6 Mil plastic which cost me about $70. I will not use it again though because it cracked after 1 summer.

But the frame is great and since it is not all one piece it can be dismantled and moved or re potsitoned. The frame was about $230 if I remember right and I am glad I bought it even if the plastic was not a success. You can buy green house quality plastic for this idea and it will last much longer.

As for peeps using PVC and making their own small green house it is important to know that "IF" you use plastic it is best to keep it from contacting the pvc as it will react and deteriorate or at least this is what I am reading online. They call the PVC designed greened houses "hoop barns" or "hoop houses". It is a growing trend and a great way to start and not have to spend allot of money up front.

Anyway this was my first green house and I need to improve it but at least I know now what to do and not to do the success I feel I had on a scale of 1-10 was a 8 because I ended up with amazing growth even had snakes and praying mantis living inside. ..

[badflash]

Thanks for the tip on interaction with PCV. I had not heard about that.

I bought a pipe bender that is designed to bend Galvanized Fence Top Rail. 3 11' sections will make a 20' diameter half hoop. String them together and you can make a hoop house any length you want. I've be covering mine with greenhouse film once we get a thaw.

[JeffW]

Yea that surprised me too on the PVC, I found that to be true on more than one web site when they mention the chemical dissimilarities will cause this problem.
http://westsidegardener.com/howto/hoophouse_faq.html

I want to go with green house grade polycarbonate next time.

The light wave reflection inside a green house is more involved than I ever knew and it was what made me go with plastic instead of a glass structure.

Interesting the north side of green house you would think tomatoes would grow mostly on the south side of the plants but they grew as well on both sides north and south yet these bushy plants were so tall and thick they shaded the ground yet the north side of plant developed as many tomatoes as all others no matter where they were located in green house.

Also the north side (outside of greenhouse) we had 10 foot high sunflowers growing and I thought it would be way too shady for suns light waves to bounce around for uniform growth yet they did well. I was thinking they might end up like a bush next to a house that tends to grow out on one side...quite amazing.

Heat was a major factor that caught me off gaurd as it was much more intense than I was prepared for so next time I will be venting with better care and planning.

I'm here to testify about PVC and plactic. Mine went the way of the wild goose so I'm basically doing a redo and starting over with metal ribbs. Cut up the PVC ribbs and made grow tables out of them. That'll teach 'em

[JeffW]

Hey there ya go always find use for left overs.

I usually just put mine in the frige for later but in this case, yep...good thinking.

[JeffW]

ribbs--> I just got it...LOL

[jackalope]

I read a site last night that promotes the use of rebar for the hoops/ribs. I think he was using 3/4" rebar, and used 2x4's to space and re-inforce the ends. Of course, he sells the woven poly greenhouse covers, so he didn't use 6 mil painter's plastic, but it sounds as if it might be a plan ...... that is, of course, if rebar isn't too much more expensive than the top rail for cyclone fences. the bender is only $39.99 for starts on Ebay (they want $88 on their web site, so don't plan to pay $39.99 for it . I'll be checking in to the rebar this summer to see if it is viable. Thanks JeffW for the mention of putting the sides into the wind, we get some ferocious winds here, so that's good to know.

On the subject of using painter's plastic, if you wrapped the hoops in the same kind of plastic, would it last any longer. I'm not so sure .... Most of the times I've subjected painter's plastic to the elements, it wears out in one season, PVC or not, 6 mil or not! The guy mentioned above, wraps his rebar in the woven poly to protect the cover, so that's why the question about wrapping the PVC.

[JeffW]

Not sure about the wrapping, all I know at this point is that even that 6Mil could not handle the heat and cracked on me. This was a metal frame so the issue was not the PVC but simply that the plastic can not handle that high heat in the top (sometimes 100/F easy up in the top area).

The rebar I read about is sections driven into the ground so that you can then bend a section of PVC over and stick it over the rebar thus holding the pvc in place. Or as you say it can be tacked to lumber with fasteners like pipe clamps you see in hardware (metal and plastic types).

The wind reached 75 miles an hour last summer (tornado near by) and that plastic and green house stayed in it's place and nothing was used to hold it down, it was just sitting there. So I learned about the wind and what these can handle (which is allot really). But the heat was the factor for me and I did not have a good ventilation so it was partly my fault. However this plastic was not designed for this but I had to see for myself being so stubborn.

I would rather use clear (green house brand) polycarbonate but I was low on cash. I did learn allot from the effort and it was fun. People in neighborhood all think I am either a nut or a interesting person, some pulled over and wanted to ask me about it so I give them tours and we meet people that way too.