Finally started pole barn - 40x50

[cowpen]

Toro: Thanks! It is a lot of work, but I'm having fun with it. Slow and steady - no deadlines - no pressure.

Rex: Yes - they're marine-treated - about as treated as you can get from what I understand. You can see some light green powder on a few of them. This is the toxic copper compound that's still leaching out. The treatment doesn't reach all the way to the center of the poles, but it's very hard fat yellow pine.

My contractor buddy is going to bring a lull (telehandler) over on truss raising day. I was sweatin' bullets over how I was going to do it until he offered that. Should be a piece of cake. I was going to rent a rough-ground scissor lift to do it, but United wanted almost $1000 to deliver one for a week. I thought they were slow these days?

 

[cowpen]

After the poles were in the ground, I set up a laser level in the center and shot & marked an arbitrary reference line on all the poles. The laser line was impossible to see in the daylight, but my buddy's kit also included a detector that clamps to the story-pole. This thing could "see" what I couldn't.

After marking the poles, I used the one that was on highest ground and measured down from my mark to determine grade and set what will be the top of the concrete after I pour the floor. Then I could mark the poles for notches at the top to carry the truss beams.

I'm sure most everybody here already knows how to do this stuff, but maybe my overly detailed explanation of "determining grade" might be helpful to other construction newbies like me.

 

[cowpen]

Here are the beams that will carry the trusses & rafters. They're 40' long and will span about 13' between poles. They're doubled-up 2x10's with 1/2" plywood sandwiched between using plenty of glue and nails.

I needed a long flat spot to build the beams so they didn't end up with permanent bows in them. I ended up lining up the scraps from my poles every 4 feet and leveling them with a string. Worked great and I didn't have to bend over as far to glue & nail.

I built the first two beams using the 2x10's I bought through craigslist (these are the red ones in the photo). They're good straight boards, and marked No.1, but I think they're spruce or fir and I found one rotten one in the stack. The rest seem fine but I've decided I'll use these to hold up the rafters. I went and bought some good hard yellow pine to make the beams for the trusses. I nailed on 4-5" centers with 3" full-head ring shanked nails. Thank God for the nailgun!

The trusses will be on 4' centers, so only my gable end trusses will rest directly over poles. The idea of sagging concerned me, but everyone I've asked about it assured me that double 2x10 beams are plenty substantial. I hope they're right!

 

[weldingisfun]

You are looking good! Keep the pics and commentary coming.

 

[Danno1]

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Cowpen,

What about hurricane uplift? Someone on a different thread was talking about nailing a cross piece to the bottom of each pole.

.

 

[cowpen]

Danno:
Uplift is the biggest concern here as far as roof loads are concerned. I really don't have any idea how to calculate it, but I do know that I'm more vulnerable because the barn is open on 2 sides.

I asked my contractor buddy about it. He's not an engineer, but he said that in addition to uplift, high winds add significant side forces on the poles which increase the resistance to pullout exponentially. He gave an example of trying to pull up a fence post. You can do it if you pull straight up, but add even a little sideways force, and it's not coming out.

Anyway, he was confident that the metal would peel off the roof before the posts lifted out of the ground. That's pretty much what happened to the pole barns in this area after Charlie and Wilma blew through. Lots of peeled back roofs, but no lifted poles. Most barns around here are open on at least 2 sides.

I'll post a couple more pics tomorrow to get the thread up to date. Then I'll pour out the big bucket of questions!

 

[cowpen]

Thanks to the time change, I had enough daylight after work last night to finish cutting notches at the top of the first row of the taller poles.

I left one of them long in case I needed to use the top as sort of a "gin pole" to help me hoist the beam up to the notches. I think the FEL will almost reach, but it's hard to tell until I get the beam chained and lifted. It's gonna be close.

I have to admit that this aerial chainsaw business is not my idea of a good time! To be honest, I can barely cut straight and square with a chainsaw when I have both feet on the ground, much less balanced on a ladder 12' in the air! I did end up cutting the last one from the bucket of the loader. I know that's not exactly safe, but it was a lot more stable than the ladder.

Any tips? I've got 12 more to cut!

 

[cowpen]

So I've been fiddling around in Sketchup with a slightly different roof design which I think looks a little better. It would also block more of the afternoon sun from shining in on the west side. But because of the drop down, I'd have to give up at least of foot of height at the eaves - even if I changed the pitch to 3/12. The other downside is that it would be a bit more expensive and time consuming to do this way.

I'm locked in now at 12' high trusses, but it's not too late to use this alternate design on the shed rafters. What do you think?

 

[TwinWillows]

FWIW I don't quite understand why you'd want the roof of the 10' side to start under the overhang of the main roof .

A little change in detail like that might not appear to add much work or $'s but from my experience (see my barn photo) having an overhang/wall/roof transition is a LOT more work & cost than your first design. Another observation, on my overhang/wall/roof I had quite a bit of vertical room to work on the wall & soffit for the high roof where you look to have only inches.

 

[cowpen]

Sorry for the long hiatus. I've been meaning to update this thread for a couple of months now. Lots of progress to report.

We used the tractor to lift the 40' truss support beams into the notches. Loader couldn't quite reach high enough to do it in one stab, so we tilted one end up to the notch, tied everything off, and then moved over a little to lift the other end.