Today we returned the tiller we rented to work our garden beds yesterday, and spent the morning running errands in Grants -- including picking up more coffee grounds for the greenhouse, and chatting in the coffeeshop about gardens and local resources. We even got to briefly meet our county's master gardener, who we will definitely invite out to the farmstead!
We got home in the afternoon, so got out to the greenhouse site at 1:30. We decided to prep the frame pieces so that tomorrow we could work all day assembling it.
The main frame works like this...
There are the vertical anchor posts with an eye atop each, which we previously set in concrete along the north and south borders, every ten feet
There are twelve-foot-long horizontal beams that go through the anchor post eyes along the north and south borders
Every six feet along the horizontal beams is an arch (south face) and back (north face) pair. These connect at the top, and each piece has an eye on the bottom that slides onto the horizontal beams.
There is a third set of horizontal beams that goes through an eye at the top of the arch pairs
We started by putting together the first two arch pairs, to get a feel for the process. We needed to know how hard it would be to carry them, lift them, and attach them to the horizontal beams, and whether it would be easier to screw the arch pair together before erecting them, or put the pieces up separately, and screw them together at the top.
We decided to screw each of the arch pairs together. We staged half of them at the east end, and the other half at the west end.
Chip went through and pre-drilled each pair. I followed behind and screwed them together. That went very fast. We decided to go ahead and erect the next arch. We walked each arch down the greenhouse trench, propped it up between the two beds, then walked back around to the upper beds (Chip on the south bed and I on the north), maneuvered the arch upright, and slid it onto the horizontal rail. We added the horizontal rails as we went.
It's a little funny because each section is different. The frame extends 3' beyond the last anchor post on each end. So starting from the east end, the arches are positioned at 0, 6, 12, 18, 24, 36, 42, 48, 54, 60, 66, 72, 78, 84, and 90. The anchor posts are at 3, 33, 43, 53, 63, 73, 83, and 87. The horizontal rails start at 0, 12, 24, 36, 48, 60, 72, and 84. Once erected, the arches slide pretty easily on the rails. But you have to keep it all straight and be careful to "button" each piece in the right order. The first rail went into the first anchor post, with an arch on either side of the anchor post. The third arch also went between the first two anchor posts, but on the second horizontal rail -- so we slid in the horizontal rail, erected the arch, and screwed the horizontal rail together. See? Confusing.
But really, the frame is so forgiving. There's ample clearance to slide things around, and the steel sections are so robust that you can have an arch on a horizontal rail that's dangling from one anchor post eye, no problem. And you can move the horizontal rails around with the arch on them pretty easily, too.
Once we finished the east half, we realized we still had an hour before dusk -- we were on a roll! We decided to just whip out the rest. We got all of the arches in place. Now we can really get a feel for the space. Above ground, the greenhouse has a very low profile -- we'll still be able to put a reasonable shed-sized door at the ground-level west end (where I'm standing). From the greenhouse floor, the peak soars overhead (where Chip's standing). The east entrance is about two feet higher than the lower grow beds and ramps down, so we'll be able to put full size double doors there, if we want. (So Chip just might be able to talk me into bringing the Ditch Witch in, even after we have the end walls built!)
We are thrilled at how quickly today's work went. The first photo here was shot at 2:36, and the last at 5:16. The frame is not done yet, though. We still need to thread the top horizontal rail pieces through the eyes at the peak. We'll also eventually need to frame out the end walls, and one interior cross-wall. Each arch will also be screwed to each of the three horizontal rails -- right now, only the first pair is screwed down. The rest will be secured as we install the siding, to ensure that the frame exactly matches the Lexan panels. Still, all in all...