You can really build this very cheap greenhouse. To get there, you will have to recycle, improvise and scrounge. If you buy all the parts and items, it will cost you more but much less than the price of a trade greenhouse. The construction of the doors of the greenhouse is the subject of a separate article. After some research, I decided to build the structure of my greenhouse with PVC plumbing pipes of 6 m in diameter 16 mm. Some similar greenhouse designs use short pipes (3 m) and pipe fittings, but I save a lot of money using long pipes without fittings. The simplicity is improved. Note however: You can carry 3 m hoses in a van, but transporting a 6 m pipe requires a truck and preferably a ladder carrier. However, you can cut them in half directly from your supplier and then assemble them on the construction site with the coupling integrated at one end of the hoses 6 m long. The 3-m hoses do not have the built-in couplers. Just go to your supplier with a saw or a tube cutter. My greenhouse will have a width of 3.4 m and a length of 4.5 m and a height of about 7 and a half feet in the centre. You can create a greenhouse the size you want, but the width of this design should be between 3 m and 3.6 m. This width makes the sides quite vertical during the first tens of CM. I have noticed that in some greenhouse designs, the outer surface is almost unusable due to the low height.
If your greenhouse is too flat, it will collapse!
You may be tempted to expand and lower your greenhouse in order to get more space on the ground, but be careful. If you have heavy rains in your area, it will slide much better than if your greenhouse is approaching the half circle. If the greenhouse shape is too flattened, it will collapse from the first time it rains very hard!
Where to start to build your greenhouse
I decided to start construction by first building the gables, although it would be more fun to set up the main structure in about an hour. I think it will be quicker and easier to first build the ends on a flat floor. I temporarily fixed the tube to a board to establish the contour.
Pre-drill the hose and use a screw so that the hose can swivel to the angle it is naturally aligned with.
I have used treated wood for most of the end frames of the greenhouse, although I usually try to avoid the treated wood in the culture space. In this case, I think it is necessary, otherwise the greenhouse would probably not last more than 2-3 years without rebuilding the framework. In any case, I will try to keep it as far away from the ground as possible. Build the rest of the frame according to the size of the door you want. My door will measure 1.5 m wide, but in most cases, 1 m wide will suffice. If you want a more permanent greenhouse or if you live in very rainy places, you will need to use more substantial wood. I used a bit of weather-resistant glue at all the assemblies to make the construction more rigid. Mark the final contour once the wooden parts have been assembled. Watch out for the screw on the saw line! Anticipate… Now just cut on the line-I used a jigsaw, but you can also use a hand saw or a circular saw if that’s all you have. Just make a straight cut in pretty much the right place. Now attach the hose to the outside of the frame. I used screws and metal ties because I’m a guy of the kind to use belt and braces. The frames of the pinions are reasonably light and very rigid.
Inner side of the frame
and the outer face… Note that the plastic that will be the roof and sides of your greenhouse is going to fold on its ends and staple to the wooden parts. If you do not have enough wood at the ends, you will not be able to fix the plastic properly and you may lose it in case of gale or heavy rains. If the summit collapses, it holds the water, makes it heavier and sags more so it holds more water… It will eventually collapse. And obviously you don’t want that!
And now the plastic cover
After stapled the plastic to the front, turn the frame over, fold the plastic and staple it to the back. You just have to fold the surplus as you do. Fold so that the condensation does not accumulate under the folds. Then cut the excess. Careful not to make a failed cut! Cut the plastic from the door opening. Leave enough to fold it in half before stapling to the frame. Notice the cuts at the top corners. Mark the locations of the door sides on the floor and install fence posts or long rebar on the sides of the door frame. Check that the fence posts are plumb fasten the frames of the greenhouse door to the fence posts with metal fasteners, wire or rope. Once the door frames are in place, pull a string to mark the alignment of the hoops. Push the rebar all the meters to secure the intermediate hoops. At this point it takes about 2 minutes to install the PVC pipes for the intermediate hoops and the greenhouse takes shape. For a stronger, more permanent structure, multiply the hoops by approximating them, or even using a larger pipe. The total working time so far is about two and a half hours. I think removing the greenhouse next summer and going back in the fall will probably take about an hour or so. I’ll see when the time comes. Since the location where I build my greenhouse is not level, I had to lift one side of the pinion frames with planks that I cut to fit them. If you live in an area where it rains very hard, you must add a 60 mm PVC pipe to the top of the frame as follows: This 60 mm PVC edge on the greenhouse prevents the plastic from collapsing in a pouring rain and prevents the structure from collapsing . I put a screw to connect the hoops and the umbrella pipe, but I also attached a plastic link around each intersection. As I said I wear a belt and braces… These 4 wooden slats regularly distributed on the vault allow to stiffen the whole. They are screwed and attached. If you look at this image, you will see the wires that serve as an X-brace on the sides of the greenhouse. I used a double wire that I attached to the top and bottom of the ends using a washer and a screw. I then used pieces of wood to twist the double wires and tighten them. No need to force, you just want them to be snug. These cables contribute to a large extent to make the whole structure stiffer and more robust. For plastic coating: measure and cut your piece of plastic, plan a little more in all directions. See the construction of the greenhouse doors.