Thursday, July 8, 2010

The Structure Takes Shape

Work continues on the greenhouse as we can. Summer schedules, especially for interpreters like myself, are supposed to calm down and get much more open, but with the work I have plus choreographing shows plus teaching two classes plus writing two (three?) plays, my days seem to be pretty full. This also explains why I don't blog about my every move in the garden right now.

So, in the last greenhouse post, I mentioned that I had removed the fence around the garden, then dug down and cleared the area just inside the landscape timbers. Next, I took 2' length of 1-1/4" Schedule 40 PVC and drove them down into the ground around the perimeter, then used pipe straps to attach them to the timber:
As you can see, these form the sockets for the ribs to fit into. They are drilled to allow two bolts to go through the pipes and secure them.

Next came the ribs. These are 1" diameter pipes that fit inside the sockets and are bent to form the main structural element of the greenhouse. Many hoophouse builders get very long pipes and simply bend them from one side to the other, giving a rounded arch shape. Melissa and I decided to use 90-degree elbows at the top that poles from each side fit into:
This gives the greenhouse a look more akin to a Gothic arch (a vesica pisces for you sacred geometry types) which we prefer to the Quonset hut look. We also think the steeper pitch will shed the rain and snow better. the next challenge was the shape of our garden. It's straight on one side, but on the yard side we curved the bed and the adjacent path. When we designed the landscaping years ago, we only had a flower bed and a tree where the garden is now, so we thought a curve was more aesthetically pleasing. It means that our poles will be longer on one side than the other, and there will have to be some adjusting to make the peaks of the arches line up on the centerline and at the same height.

After the poles were up, it looks like this:
You can see, especially in the first of these pictures, that we have not yet adjusted the peaks. The next steps will be to add a purlin (a ridgepole of electrical conduit that connects the peaks and adds some stiffening), build the end walls that include a door on one end and a window/vent on the other, and (for now) run deer netting around the thing to keep the squirrels (and the dog) out. The greenhouse plastic won't go on onto late October.

Sort of looks like the Air Force Academy Chapel, doesn't it?