Sunday, December 4, 2011

High tunnel reaches new heights

This was a major weekend for the great high tunnel adventure. I sent out an APB on Tuesday night to see if some folks would be able to come help wrestle rafters into place and low and behold, we got a bunch of folks interested and more showed up unexpectedly and it wound up being just enough to get through the tough part of figuring it all out and on to the production mode of getting these huge rafters up and into place.
It was hard to figure out what to do at times - there were so many unknowns, and things did not fit in place seamlessly by any means. Lots of muscling steel things that did not want to be muscled into place. The first day, we got five trusses into place, including the two we already had set up with purins. Mike's strategy was that rather than setting the whole thing up based on one perfectly-level truss, we would attach the purlins to two trusses and hoist them both up at the same time. We did that, and it went fairly smoothly except that the posts had become slightly bulged at the top when we hammered them into the ground, which was fine except that the bolts weren't long enough to deal with the bulge. Luckily, my neighbor Craig showed up with his grinder and ground down all the rest of the posts on day 1 and after that, it was much easier to get everything flowing.
So after getting five joists up, we called it a day, and that night, it poured and rained and blew and it was crazy outside. When I got up Sunday I opened the door to find the water tank had rolled through the yard and was perched near my front door. Yikes. That's a storm, right?
Anyway, didn't figure any of the people who had pledged to come back the next day would but I was wrong - they all showed up and by 1:30 we were running at full steam, having figured out how to assembly-line all the little jobs (inserting sleeves into the top pieces of the rafter to keep the chevron from collapsing when it was tightened, putting on the cables on every-other rafter, etc.
On day 2 we also had use of two 12-foot stepladders that were hugely helpful for getting up to the top parts of the structure, which is 14.6 feet high. Tall, brave people climbed up those ladders all day today, and I never did - I'm a chickenshit, I know, but I prefer to think of it as having a healthy respect for gravity.
We put up the bottom row of purlins on each side as we went and, with three people (one on the ladder holding the center, one on each side, we hoisted the truss up and over the lower purlin and then onto the top of the post. An extra person on the first side is helpful to get the bolt in while holding the end of the truss in place.
Then the second side is hoisted onto the post, and the person on the center lifts their piece into place, and bolts go in, and tada - you have another truss up. There are 19 of them, and at first it seemed impossible, but by the end of day 2, it was going pretty smoothly. Our trusses already had cables attached to them to keep the sides from bulging out. Some people did every third one, but we got a screaming deal on some cable, so we did every other truss with turnbuckles. We put each truss on a jig that Mike made that was exactly 30 feet across at the bottom and then fitted the cable on. That worked well in keeping things moving smoothly, but putting up the trusses with cables on them was a little more difficult than the uncabled ones - you have to watch where you put your ladder or the cable gets in the way, and you have to thread the cable through the purlin, but still, not too bad.
The only other complicated part of doing it this way is that you have to put a new purlin in every fourth one, but you can't put it in when there is nothing else to attach to because it will be hanging out there too far, so we put one truss up without the purlins to support it and then backtracked while holding the truss up with boards from below and attached the purlin to the connecting truss and the new truss at the same time. Then we added two more trusses and did the whole thing all over again.
Not sure if that will make any sense to the reader, but I'm writing it all down because I have googled the installation of Farmtek's Pro Solar and found no one who has written about it and by the time I get too far into the week, I'll have forgotten myself.
Other things we found - when you run into a purlin that doesn't seem like it will fit, try loosening the bolt on the connection of the truss to the post, then repositioning, and tightening again. That seems to be easier than trying to persuade it with brute force.
I'm beat from two days of not only putting up a tunnel, but also kid wrangling (the kids did a great job of entertaining themselves for four hours plus each day while I worked outside - applause to them) and feeding the masses. I feel like I've run a race, and I suppose in a way I have, and what a sweet prize this time. Pretty soon, I'll be ready to sit and look through catalogs and plan what I'm going to plant. That will be quite fun, I believe. Quite fun.

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