Building a hoop greenhouse has to be the easiest hands-on carpentry project you might undertake! It only requires you to draw up an easy functional design and a step-wise plan to get the structure up in a couple of hours. The catch is that you have to calculate with some accuracy the quantity of material you are going to need. If you have good math, that would help!
You are going to need PVC pipes, tie wraps, fence clips or staples, rabars, polyethylene sheet and some treated wooden board lengths. A basic carpentry kit should be fine. The first step is to identify the site, clear and level it. Next, you need to measure the area you plan to cover. Mark out the perimeter using a measuring tape and stakes. Drive the stakes into the ground at each corner. You can pull them out later.
Once you know the length and width, work out the approximate length of the PVC pipes you are going to need for the ribs, the purlins and the central ridge. One-inch schedule 40 PVC pipe is good for building a hoop greenhouse. You have to work out how many wooden boards of a standard length you are going to need based on your design. Wood will be used along the base of the greenhouse, in building the support frame for the door, the door itself, and for supporting the side walls.
Using the stakes as reference points, divide the entire length of the greenhouse into four feet units. Drive in rebars to a depth of about three feet into the ground at each mark. The rebars should project about three feet above the ground for you to be able to slide the PVC pipe over them.
Attach the central ridge and then the purlins at the sides. Make the frame for the door and the end walls. Stand the frame with two vertical beams driven into the ground. Attach the door with hinges. You can either build a closed wall at the opposite end or make another door. If you do not have any vents in a relatively large hoop house, the doors at both ends can be opened for cross-ventilation.
Now stretch the polyethylene sheet over the entire structure and secure it with tie wraps or clamps and clips. Use lumber to weigh it down around the base.
With proper design and material building a hoop greenhouse is a fun activity that you can enjoy by yourself or with your family.
