Greenhouse Construction Project

When we realized that there might be some potential to grow Heritage Produce in our yard, the thought of a greenhouse came to mind. What would be better than to have a controlled growing environment right in our own back yard? With that, planning started. A modest greenhouse can be purchased for about $4000.00, one with a steel frame, about 20 feet by 40 feet in size. It needs to be shipped to site, site prepared and greenhouse built, covered and ready to go. Our frugal ways challenged that there must be a less expensive way to accomplish this. With a bit of reading and some prior background in wood construction, I felt I could build a frame that would cover 1000 square feet of ground for about ¼ the cost of a purchased greenhouse. I drew up a truss pattern, did a layout, then scaled it to size. Using 1x4 material, wood glue and a few pounds of screws, I started building 22 half-trusses. Each pair were to be set five feet apart, mounted on steel anchors, giving us a 24 x 50 foot unit.

 

Once all the trusses were constructed, the next major step was to prep the ground prior to placing the greenhouse. We wanted to get as much soil loosened up as possible, so we used the plow and set it to cut at maximum depth, turning well over 8 inches of fallowed soil. From there, the area was surveyed to determine level, string-lines were placed and the steel anchors were driven into the ground. Then the trusses were placed and tied together with a simple 1x4 ridge piece being installed as we went.

Once all the trusses were placed, we had the whole family out to pull the plastic up and over the frame.

With that, end wall structure was built and the greenhouse was closed in, complete with door frames, roll-up vents made out of ½ inch electrical conduit attached to the bottom edges of the plastic. In the year following, we added micro-sprinklers along each side of the greenhouse, hanging from overhead, allowing the most natural method of watering the plants. The last photo shows the lush production  The total project cost was about $1100 including the plastic - about 1/4 of the cost of a commercial unit.