I have a quonset-style garage, one with the tarp-like cover that I want to convert into a greenhouse. The company makes a greehouse kit for this building but it costs almost as much as the silly thing did originally. I am thinking I could probably cover it myself with greenhoues fabric for less (haven't priced it yet though) but wondered how I would secure it to the framework. It is metal tubes. The building is 12'x20' and somewhere between 9 and 10 ft high at the top, as far as I can tell. Some of my thoughts are installing a 2x4 ridge pole and purlins about halfway down each side and stapling the stuff to it. I then thought maybe I could staple the bottom of the plastic to 2x2s that could be fastened somehow to the pt 4x6 I used as a foundation or could be rolled up to allow ventilation. I would probably also need some way to ventilate the top of the thing also. I will frame the ends for doors and vents too. When I enclosed the one end for the chicken house I used the metal strapping with holes in it that is used to hold pipes to secure the 2x4s to the metal tubing. I would probaly use pipe clamps to hold the ridge pole and purlins to the framework and the strapping to secure the uprights at the ends. Will this work or is there some other way to do it?
Been thinking about the same thing lately, using just el-cheapo 6mil plastic.
I was thinking of attaching 2 furring strips about 3/4 of the way up each side. Then attaching the plastic to each side, leaving about a 2' wide gap along the ridge. Along the ridge, I was going to run regular window screen the entire length, to keep the bugs out, but provide a big roof vent for summer time use. For wintertime, I was thinking of attaching a long strip of plastic to poles, using bungie cords to hold the 'lid' over the screen top when needed, and partially releasing one side (to vent) when it gets too hot.
The ends would have flip down screened covers so I could move it around as well as vent when hot. We're trying to avoid using power whereever we can on this project.
For all you dedicated scroungers out there here is something to think about. When I was young and working, I used to install retrofit windows in homes. Included in the changeout were patio doors. No matter what the brand of the original door they are one of two sizes of glass. Most all of this glass is tempered or safety glass that is hard to break and if you do it shatters into more pieces than you'll be able to sweep up in a year. Look for the safety label etched in the corners of the glass; without it they are NOT tempered and I would NOT use them...just too hazardous if you break them.
Go visit your local replacement window contractors and ask for the old patio doors...what you get are the two lites, not the frames, because the frames must be destroyed in the replacement process. Strip off all the aluminum, save it up and take it to the recyclers when you have a nice pile. The glass falls into two sizes, both the same width, but one about 2 inches longer. When you have gathered enough patio door glass you have the makings of a mighty fine greenhouse. If you can frame a storage building you will have no problem building such a greenhouse.
If you are in a colder area use only insulated glass patio doors. I'm not and used single glazing. Can't tell you how many doors went to the dump in a year, but WAY more than you need.
Another fringe benefit is that the recycled price of aluminum is rising. I hauled in one load on my trailer and walked out smiling nearly $5,000 richer.
Most companies have employees who salvage the aluminum, but the glass goes to the dump. You could get lucky and find a company that doesn't care...I did and I recycled the aluminum for a year before the competition pushed me out. Lotsa bucks came my way that year.
Think about it and do a little research in your area. Maybe you can gain multiple ways here.
I bought heavy-duty woven greenhouse poly from Peaceful Valley (groworganic.com). I can't quite remember how much I bought, but it was more than enough for your project, and I think it cost about $140. They order it from the manufacturer to your approximate dimensions. It seems to be as strong as a good-weight blue tarp. The cheap plastic will deteriorate very quickly and it will not handle a lot of wind or pokes.
Why not just buy the Z loc track to secue the plastic? It's not cheap but it's not a new mortgage either. You can add a stick on foam strip to each arch and I'll bet there are spray on rubberizers you could use instead. It keeps the plastic from sliding on the arch in the wind. I should get my greenhouse finished...... I say that every year. Bent the arches myself, bought the plastic, and Zloc (just for the ends) and plan to secure the bottoms and ridge vent with wood strapping, and it's all just sitting there! Arrrrrrrrrrrrrrgh!
Do not meddle in the affairs of Dragons, for you are crunchy and good with ketchup........
Actually, I was just at my local hydroponics shop today checking on plastic for my "carport" it's meant for a car but will be transformed to a greenhouse in a few weeks, it's a 10x 20. They told me that unless the manufacturer of the frame makes coverings for greenhouses it's really tough to match them up, but for about a $115 I could get a roll of 6mil plastic and cover it myself. They have these nifty lil' foot long or so ''clips" that slide over the round metal bars to hold the plastic in place--the guy winked and said technically I could find some pvc the same size as my posts slice them top to bottom on one side and make the clips myself much cheaper. That and all the greenhouse "tents" I found were complete set ups for about $300 and half the size of the "carport" that only cost $110.
You can lead a horse to water but you can't make him float on his back.
I have a hoop greenhouse I purchased last year. Let me see if I can explain how the covering is attached. The frame is 6 hoops attached by a ridge pole and bottom "rails". The two ends attach with clips -- cylindrical "tubes" that are forced over the tubing. As someone mentioned in an earlier post they might be able to be made with pvc. The back end has two vertical zippers to allow it to be rolled up for ventilation. The front end has a door that is attached to two square tubing vertical pieces bolted to the top of the hoop and the bottom rail. This could be easily made with wood.
The main cover is about 18" longer than the green house and 6' or so wider. It has a pocket sewn in to take a pole through it on both sides. When installed, this pocket is on the inside of the greenhouse and about 14" from the ground. The pockets have cuts in them every 6 feet to allow a strap to be run through and anchored to the bottom rail. The cover extends out on the ground to the side of the green house by about 2'. This means you'd need to make the pockets about 3' or a bit more from the ends so you'd have this extra. I would imagine you could fold the sides up for more ventilation when needed.
The main cover also has a hem sewn in on the ends that meet the hoops. A strap is run through it and when drawn up gathers the ends around the hoops. This strap is then attached to the bottom rail. A rope could be used here. At first I was a bit dubious about this method of attaching the main cover, but it has done well with 50 mph. winds. All is anchored down with long earth anchors.
I"ve only had the greenhouse for a year, so I don't know how durable it will be, but the cover is "guaranteed" for 5 years but the supplier said it should last longer.