10 May Hoop House Construction 2 Arches
I’m Ron Patterson with Utah State University Extension in Carbon County. We’re going to move into our next phase of our high tunnel construction; I’ve got the T posts all in place now and I need to make the arches. So what you need to make the arches, you need PVC – some inch-and-a-half PVC – there will be eighteen inches that will slip over every T post. So however many T posts you’ve got you’ll need eighteen inches of PVC – approximate doesn’t have to be exactly eighteen – it’s just kind of a sleeve to slip over the T post. You’ll need a one-inch PVC that will form the arch, and then we’ll need to glue it together with some gloves. You’ll need to have a 45 degree inch and a half elbow, and then a-a bushing to reduce it from inch and a half down to inch.
So we’re going to go from this inch and a half and go down to put the inch inside that and then we’ll arch over the top to the other side. So for every arch you’ll need to have: two eighteen inch-inch and a half PVC,two inch and a half 45-degree elbows, and two reducer bushings inch and a half to one inch reducer, and one twenty foot one inch PVC. So however many arches you’ve got that’s what you need to do. Just, if you divide the 20-foot PVC by eighteen inches, you can make thirteen eighteen inch sections out of a twenty foot piece of PVC. So we’ll need to cut this PVC into proper length; to cut it you can use…you can use a hacksaw, but the teeth on that is so fine it’s-it’s a really slow process.
If you’ve got a good sharp back saw or wood cutting saw that will cut through the plastic just fine; not too coarse but course enough to cut through, so if you’ve got that kind of a saw that’s good. If you have a a sawzall and then you can… you can use a sawzall and it’s a lot faster; the coarser the teeth the faster it’ll cut through the plastic. Not quite as smooth of a cut, but we really don’t need to have it smooth, we just need to have these sections cut off and then we’ll fit them into the fittings. For the inch PVC, I don’t have a tool – a PVC cutter – big enough for inch and a half, but for the inch size PVC what we need to do is cut the bell end off. Because we’re going to be slipping each end, and so you want to make sure you cut that off to where it will fit and slip in to the bushing. So that will go on there like that and that will go on there like that.
Now when it comes to gluing well, we’ll put these together here in a few minutes, but when it comes to gluing you don’t need to glue everything all together. I would glue this one right here, and then these up here really don’t need to be glued because of the pressure, it will be keeping that in pretty good. If you want to you can glue them, the trick is to make sure that it’s at the same same angle on that end as it is on this end. Otherwise you get a twist on it so…so it’s up to you whether or not you glue both ends, but I would at least glue this bottom end on the – on the elbow – on the 45-degree elbow. So you’re going to use some noisy power equipment, it’s not that it’s really noisy but it’s a little bit noisy, we’ll put in the ear plugs…and my safety glasses. I got this marked off it 18 inches so all I got to do now is cut through it. That’s how we go for every T post. So on my high tunnel it’s 93 feet long, so 93 divided by 3 – so I’ve got 31 – plus another T post, I’ve got 32 T posts on each side of the high tunnel. So you divide the number by 3 and add 1, then you do that for each side, so I need to have 64 18 inch inch-and-a-half, sixty-four elbows, and 64 bushings for each arch, and 32 inch PVC pipe to make the arch.
Now if you’re going to glue these together – this is kind of cold so my glue, I should have warmed it up a little bit – but just a little bit of that PVC cement. Stick your elbow over that; we’re not trying to form a water seal or anything so it’s not critical to get it …a good tight seal on it we just want it to stick so…So we’re just going to kind of glue it in we’ll do that on each side; I’m not going to glue this one right here. Now PVC will break down into sunlight over three or four years it will turn black and get very brittle, so to make it last a little bit longer just paint it with some exterior latex paint. And that will help that to last quite a bit longer, several years probably – double its life at least. So anyway, this is an arch that I’ve had on an older high tunnel so it already has a little bit of a bed to it, and we’ll put this one up. So when you put these on you want to try to make sure that you’re close to the same; that’s the reason I don’t glue it here, is so when I get it set up if it’s not quite even here – if I get up this way or down this way a little bit – I can adjust that if it’s not glued. If it’s glued then it’s set in stone, so I just do that just to give myself a little bit of flexibility.
Now that we’ve got this – this is a lot easier to do if you’ve got two people doing it, so I’ll have my lovely assistant here helping me slip this over the T post – you just take that down. I’ve got the t-post grounded off and it’s all ready to go. So I’ll be able to stand these up straight when I get my…my ridge piece going down-down the middle, I can stand and get those evenly spaced. While the ridge piece is still on the ground I’ll take the measuring tape and- and mark on it every three feet. That way I’ll know where each of the arches will fit, and we can get it to look kind of good – we’re not building a rocket here, but we want it to look decent. So every three feet then I’ll mark that ridge purlin and then I’ll know where the arches fit. One more thing I want to do before we put the ridge piece up there: show you how these cross connectors work. They’re just two bit pieces that bolt together; you want the arch to be over the top of the ridge piece. So this will hang on the arches like this and then it will connect under the ridge piece, and you just run your bolts through there like that.
Of course you’re going to be doing this up in the air so you’ll be looking at it from underneath, but that’s the principle: putting up the arches and connecting them with these cross connectors. Now you can take screws and just screw up from below – it’s best I found if you drill a little pilot hole to go through that – and your screw needs to be at least 2 inches long. There’s always a possibility of that pulling out and causing problems; I’ve had a couple break in the past but not anything serious – not any serious problems. The cross connectors are a little easier, take a little more time, but they’re little easier to do. So you make your marks, and you put your ridge piece up, use these cross connectors to hang them on the arches so the ridge is hanging on the bottom of the arches.
I’ve got my ridge purlin up in place now, I need to straighten it out and I’ll show you a trick on how I can do that. I’ve got the ridge purlin up but you can see I don’t have my arches spaced very evenly, so as I straighten out the ridge purlin I’ll also want to make sure I get the gaps correct – the spacing correct on the arches. And so I’ve marked my ridge purlin with the 3 foot marks and as you go through and tighten that up, I’ll put everything in place and then we’ll be up straight and ready to go. When you’re doing the ridge piece there are a couple of things: of course we’ve… we’ve made our three foot marks so we know where to put our ribs here along the ridge piece, but I also run this line – I don’t know if you can see it very well – but there’s this pink line I’ll run it straight down the end.
That will help me straighten this up so that…so it looks better; it doesn’t…it’s not rocket science we’re dealing with here but we want it to look pretty good, so we’ll try to keep this about the same distance from that line all the way down. And now the only thing really you need to do to put this up is a 7/16 wrench to get things put into place. Now because I do a lot of these alone…I will start out with my – putting my ridge piece up, and I’ll tie it with a piece of twine along here so it’s up in place, and then I can put the cross connectors on without having a lot of problem getting them on, holding the pipe up and everything.
So I’ll tie it up with a piece of twine and – and makes it a lot easier for me if I’m doing it by myself. If you got someone else helping you then you can probably just kind of have someone hold it while you put these cross connections on. Okay, so we’re now finished here; it’s not exactly straight but it’s a lot better – looks a lot better – we’re not building a rocket so it doesn’t have to be exact, but we like it to look nice. So that’s the end of the arches; the next segment we’ll do on putting together the…the sidewalls, the hip purlins, and the wiggle wire track, and all the things that go into the sidewall.