Make a Greenhouse From an Old Carport





Introduction: Make a Greenhouse From an Old Carport

Turn that old portable metal pipe carport into a greenhouse.

Step 1:

I used one section (out of 3) of an old metal pipe portable garage (the plastic cover rotted off) for the starting frame.
Using the carport's shape, cut wood to fit the frame. Most of the wood was from 2x6's cut in half long ways (ripped).
Although I used 2x6's across the front and back because it is a 9 foot span, since the window frame would support it, you could use smaller lumber instead. I used a 4x4 I had laying around for the side with the door. The ground here is at an angle and I wanted to be able to step on the door sill without it bending too much. The window frame is from 2x2's.
The 10 foot wide plastic fit perfectly with just a little trimming.

Step 2:

First cut each piece of wood to fit the frame and attach to the metal using pipe clamps held on with flat metal plates screwed into the wood - no need to drill any holes in the pipe.

(hint: you have to screw the clamps to the wood with the metal plates before attaching to the pipe - experiment to get the screw on the pipe clamp in the right place.)

Step 3:

The frame had a tendency to wobble a bit front to back so, for the sides, I attached crossing guy wires to eye bolts on each side using tighteners, and now it is very stable.

Step 4:

The bottom sill on the back sides didn't have room for the pipe clamp tightener so I used metal braces.

Step 5:

I used metal plates on most of the joints because I happened to have them. You could use plywood or some other method just as well.

Step 6:

The whole thing is held down with stakes, cinder blocks on the low corners, and railroad ties around the outside (just in case).

Step 7:

Make a frame for windows using 2x2's.

Step 8:

I got automatic window openers so it wouldn't get too hot inside and boxed in a frame for them from 1 inch wood and lapped the ends, attached a hinge to the top of the window, and covered the window with the plastic.

Step 9:

I used 6 mil clear plastic like they use on crawl spaces under houses. I only used half the roll, so if it doesnt last in the sun I can put the other half up and it's still a lot cheaper than greenhouse film. I stapled it on and then screwed 1/2  thick strips of wood over the staples so they wouldn't pull out in a wind. The door is a simple frame with plywood braces on the corners, hinges, and a gate latch.

Step 10:

The shade cloth on top is attached with snaps to the railroad ties in case it gets really hot. It is easy to pull it out of the way when its not needed. The black painted 55 gallon drums help hold in heat on cold Oregon nights.

The plants loved it.



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    17 Discussions

    This is brilliant!

    Unfortunately i just moved house to a new property and left an identical carport next to the rubbish bins for pickup.... and now we need a greenhouse! 
    Looking at the costs of purchasing a new greenhouse, using a carport frame as the skeleton shows a lot of ingenuity, i had a feeling it would have been worth saving our old one.

    1 reply

    So sorry you left one behind. However, you may be able to find one cheap or free on Craigslist. I found a couple for about $25. when I made mine.
    Also, although I don't know much about them, occasionally I see great deals on greenhouses from Harbor Freight that might be worth looking into if you have one nearby.

    Good luck and thanks for the nice comment.

     This is so awesome!  I know I'm a johnny-come-lately, but my friend and I have been constructing a greenhouse from a carport right now!  I just found yours tonight, and they are almost identical!  We are using both ends on this one for a larger house, and we are using window screen for corner vents, rather than windows, but mostly, they are identical.  I love your tarp cover idea!

    1 reply

    That's terrific - great minds must run along the same lines. The screens are a good idea, keeps the bugs out. I did have a problem when the nights were really cool and the days sunny. It tended to be too cool at night and too warm in the day. That's why I put in the heat sensitive window openers. I wasn't always there to open or close vents. They were only 19.99 at Harbor Freight. Greenhouse suppliers were considerably more.
    Good luck with your project. I love how mine turned out.

    Yes,hubby has some work to As we have a skelton of a large car port, we are amking the larger version, so my greenhouse will be about 3 times this size. We are doing 2 x 8 framed raised beds gardening this next year, and are using the PVC domed idea for growing early, so we can start them where they will be perm....

    1 reply

    The plastic will deteriorate with time but it's priced much better than the UV protected stuff, In our Geographic location the vapor barrier plastic lasts about three growing seasons ... Good Project thanks ....

    1 reply

    Hey, Good to know. I was hoping for at least one season. We are in Oregon ( not so much sun) so hopefully we can get 3 years. Nice to hear from experience.

    This is an awesome project - what kind of floor space did it require?

    I need a greenhouse at home myself, so this would be just the ticket, assuming I can find the necessary tubing. Thinking about it, if you found an old frame tent, that would work just as well I think? (Although that particular style would need a larger floor space than your design)

    1 reply

    A tent frame might work, but it would have to be fairly sturdy - the wood doesn't hold it up. I looked on Craig's list just for our city and found 4 of those old carport frames that didn't have covers. They ranged in price from $100. (pretty high priced) to free. If you were patient you could probably get a good deal. I only used one of the carport frame sections. The floor area is about 7ft by 9 ft. My plan was to be able to expand it later by adding one or both of the middle sections. If I used the whole carport it would be 21ft by 9 ft. Good luck

    Great project!! The main problem I have when repurposing the portable carports is that if the "roof" isn't held tight it collects water and bellies out on the inside of the pipe frame and if not emptied will rip. Really good idea with the hose clamps! Ive been using u-bolts but they're a lot more expensive.

    Beautiful greenhouse! But I'm confused.. why use the carport at all? It looks like it was used more as a guide for the shape than anything.. and then you built a greenhouse around it.

    1 reply

    Thanks for the nice comment. I used the metal because it made it easier to build and much more stable. With it as a base, I could use smaller dimensional lumber without loss of integrity. As I made it, the joints would not be strong enough to hold it up, most are just tacked together with small metal plates. You could make it without the metal frame, but would need to do a lot more bracing at the joints and use bigger lumber (especially if wind is an issue).