hoping BossHog will be in soon…
Were in the planning phase for a pole barn, 60×100 w/ 30′ of clear span in the middle & 2 15′ bays on the sides. Woodshop, weld shop, spray booth, equipment storage, junk etc. Metal roof, sides, gravel/concrete floors, laminated poles.
The last one I built I had trusses 2′ o.c. and laid 2×4’s on edge for purlins. I used 2×10’s for headers, and spaced the posts 8′.
I was told I should have spaced the trusses 8′, and laid 2×6’s in special hangers for purlins, that is the “best” way (less material cost)
If I go this way, would I need to double the trusses to carry that load? Are 2×6 big enough to span 8′? Is there a better way I’m not thinking of?
Replies
I don't think there is just one "best" way for any building. But if I was building one like that for myself, here's what I would do.
I would put the trusses and posts 8' O.C. I'd also make 'em clear span the whole 60' - I don't like posts inside buildings.
A single ply truss would PROBABLY work. But it depends on your loading requirements, if you have ceiling load, etc.
They make special "saddle hangers" for purlins that are really slick. I'd highly recommend those.
Around here 2X4 purlins are used for trusses 8' O.C. But loading may be different in your area, so you'd need to check.
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All of the above would be for an uninsulated pole barn. If you're going to put a ceiling in and insulate it, Using a closer truss spacing might make more sense.
If the trusses were 4' O.C. you could use 2X4 purlins laid flat.
If you're using metal for the ceiling, you could probaby just screw it to the bottom of the trusses and blow insulation on top of that.
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There are probably more ways to do it. Hopefully others will jump in and offer some more ideas.
BTW - A 60X100 building is enough square footage that you'd probably have to have a draftstop up there...
So what does a 60' long truss weigh & how many guys (plus a machine) would I need on truss day? I know they make them that big, but wow. 60x100' of clear span 14' high could be real useful.
I'd have our truss guy do all the calcs, of course, but 2x4s sound real small for 8' span. Saddle hangers - are the hangers you mention double sided & just slip over the top chord of the truss? Slick indeed - size it for precuts & put the saw away.
We'd build it for storage initially, but might put a metal ceiling & insulation over 1/3 or so later on (when I am finally kicked out of the garage)
My pet theory - I have noticed the boys whose dads have barns have a leg up on starting their business when they grow up - I want my boy to have that opportunity - a place to build/work/store/experiment.
Treat every person you meet like you will know them the rest of your life - you just might!
"what does a 60' long truss weigh..."
Depends on the chord and web sizes. But it would likey be in the 400-500# range if it's a pole barn truss.
"how many guys (plus a machine) would I need on truss day?"
I've never set trusses that big, so I'm not sure I'm the one to ask there. You'd need a big crane, a spreader bar, and maybe 5 guys? Trusses that big will take a lot of bracing, so that means lots of time.
"2x4s sound real small for 8' span."
Not to me. But again, it depends on the loading, and the species of purlin lumber. I have some purlin span charts around here somewhere...
"Saddle hangers - are the hangers you mention double sided & just slip over the top chord of the truss? "
Yuo. They're slicker 'n snot.
"We'd build it for storage initially, but might put a metal ceiling & insulation over 1/3 or so later on"
Then I'd suggest designing the whole building as if it would have a ceiling. You never know how plans will change down the road. And that's something you can't readily change.
"I have noticed the boys whose dads have barns have a leg up on starting their business when they grow up"
Interesting idea. I think it's based more on how and what their Dads teach them. But having a place to mess around with stuff sure is nice.
Teamwork is essential - it allows you to blame someone else.
What is a "draftstop" ?
"What is a "draftstop" ?"
It's basically a gable in the middle of an attic. It's designed to slow the spread of a fire in an attic.
Even in the best and most peacefully civilized countries many occasions arise when a woman versed in the knowledge and use of firearms may find that information and skill of great importance. [Annie Oakley, Oct. 1919]