Pole barn design

Andy J.

Andy J.

Doin’ it LIVE
Joined
Nov 5, 2005
Location
Winston
I'm planning on building a 12' x 24' pole barn when the ground thaws out and want to start gathering materials soon. I know a bunch of you guys have been down this road and hoping you can provide some feedback on this design idea.

I'm planning on using 4x4s for the black posts (8ft of height above ground) set in concrete footers, the depth of which I have not yet figured out. 24" maybe? Orange beams are double stacked 2x6s, green and purple truss members would be 2x8s and trusses spaced at 16". Blue beam would be a 1x10 or 1x12 depending on the contact area from the truss member. I haven't decided on roofing yet. This is going to butt-up to the end of an existing storage building and the roof angle will match that. I haven't measured it yet, but my untrained eye guesses its a 4/12 or 5/12 pitch. The storage building has shingles, but I haven't ruled out a tin roof. I'd like to keep it light and cheap. Also going to do some siding of some sort down the long sides (leaving the ends open), but haven't decided material for that either.

Sorry for all the technical jargon ;)

pole barn.png
 
Anything over 18-20' I'd go with an LVL for the blue "ridge beam" or it's sure to sag later on. And the 4x4's will work but won't stand the test of time unless you line it with footers and stud walls.

My 2. But I tend to overkill sometimes as well. Not fun taking something down to do it again. Sure there's a lot of different opinions though.
 
I'll echo the 6x6 minimum for the posts. I'd look at a cross brace somewhere in there, too, but I also tend to overdo things. :lol:

Are you getting trusses made? They'll design them for the spacing, loads, etc., and you can definitely go to 24" oc.

If not pre-manufactured trusses, I'd bump the green members on the short ends to 2x10 and the rafters up to 2x10 with 2x6 collar ties between rafters. Double up the blue beam to at least 2-2x10s... or to LVL, like was said above.
 
6BangBronk said:
Anything over 18-20' I'd go with an LVL for the blue "ridge beam" or it's sure to sag later on. And the 4x4's will work but won't stand the test of time unless you line it with footers and stud walls.

My 2. But I tend to overkill sometimes as well. Not fun taking something down to do it again. Sure there's a lot of different opinions though.
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I don't want to build this twice! What's an LVL?

trailhugger said:
I'll echo the 6x6 minimum for the posts. I'd look at a cross brace somewhere in there, too, but I also tend to overdo things. :lol:

Are you getting trusses made? They'll design them for the spacing, loads, etc., and you can definitely go to 24" oc.

If not pre-manufactured trusses, I'd bump the green members on the short ends to 2x10 and the rafters up to 2x10 with 2x6 collar ties between rafters. Double up the blue beam to at least 2-2x10s... or to LVL, like was said above.
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Sorry, I didn't draw in supporting braces but they will be there. I wasn't planning on using pre-manuf trusses because I assume that I can make them myself for cheaper. Not sure if that's true or not, just an assumption on my part.
 
Need Jeepinmatt to post up in this thread.
 
LVL stands for laminated veneer lumber.

This might be helpful: http://www.awc.org/calculators/

You definitely don't need to do trusses, esp. for a pole barn. I was mostly curious. My other advice stands, then. :beer:
 
Take a look at these:
http://greensboro.craigslist.org/grq/4808484088.html
And here's some pricing:
http://charlotte.craigslist.org/grq/4768517252.html
http://danville.craigslist.org/mad/4830725255.html

I found it to be the most cost effective way to build my building.

However, look at the total costs. Wood trusses were very close in cost, but I didn't want to lose the ceiling clearance (mine is 34' wide, so 13.5' at the sidewall and 19.5' at the center is 6 ft of lost clearance).

Also, for a 12x24, I'd give the drug dealer carport people a call, because those things are pretty darn cheap.
 
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And most importantly, be very cautious of scope creep. My building started off as a 16x24 shed with a 12' peak, and ended up as a 34x40 building with a 20' peak, with a 34x20 shed off one end and a 10x34 loft inside.
 
jeepinmatt said:
And most importantly, be very cautious of scope creep. My building started off as a 16x24 shed, and ended up as a 34x40 building with a 34x20 shed off one end and a 10x34 loft inside.
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haha! As an engineer, I am well versed in scope creep. Thanks for the links
 
I wish someone had warned me of scope creep when I was building an addition on my house. What started out as my desire to convert a 1/2 bath to a full bath, turned into my neighbor convincing me to build on a new master bedroom off the front. What started as a 12x15 room with a bathroom grew to a bedroom/bathroom with an office to a 18x36 master bedroom suite with a 9x9 walk in closet, 9x9 office, bathroom with separate shower and 100 gallon Jacuzzi tub.

It's done now, but it was nearly the death of me....
 
FrontPorchFab said:
I'm planning on using 4x4s for the black posts (8ft of height above ground) set in concrete footers, the depth of which I have not yet figured out. 24" maybe?
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From a cost perspective, I'd go with 4x6's. 4x4's are probably mechanically sufficient, and 6x6's are probably a bit overkill. Your strength comes from the sheeting along the walls if properly designed. The posts are mostly to keep everything in place and carry the load (which is not much from a 6'x24' roof). By putting something on it for the walls and having a roof gives you strength in the long direction of the building, so I'd want the 6" side of the 4x6 going side to side, and since it eats into the width 6", I'd just go ahead and use 6x6's because they would "look" right.

FrontPorchFab said:
I haven't decided on roofing yet. This is going to butt-up to the end of an existing storage building and the roof angle will match that. I haven't measured it yet, but my untrained eye guesses its a 4/12 or 5/12 pitch. The storage building has shingles, but I haven't ruled out a tin roof. I'd like to keep it light and cheap. Also going to do some siding of some sort down the long sides (leaving the ends open), but haven't decided material for that either.
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When I compared steel vs plywood and shingles, it wasn't that different. I went with steel because I wanted the "galvalume" color which is silver and will potentially reflect more sunlight and heat. Also, it was a much lighter load but that was a secondary consideration.
 
Falko said:
Indeed. Beware of scope creep in all projects. I recently needed to replace pinion bearings in my WJ and ended up with a tubing bender...
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LMAO! That is some funny scope creep.
 
jeepinmatt said:
Your strength comes from the sheeting along the walls if properly designed. The posts are mostly to keep everything in place and carry the load (which is not much from a 6'x24' roof). By putting something on it for the walls and having a roof gives you strength in the long direction of the building,
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In a pole barn, you resolve lateral forces in three ways: moment connections at the post/roof frame and post/ground connections, braced frames (usually knee braces or cable stays), and diagonal bracing in the roof system to strengthen the roof diaphragm against racking. Stud framing depends (to a point) on the wall sheathing and roof sheathing to resist the shear forces, but even if you sheathe your pole barn in plywood, you don't get much of a connection at the posts to be able to distribute the loads.

This video should be played back at like 10x speed, but if you skip through it, you can see how the wall slowly deforms as it's subjected to cyclical shear loads. Typically, failure involves the fasteners ripping through the face of the wall sheathing.



As with roll cages, triangulation is the simplest and strongest means of combating racking due to shear loads.
 
Hey man give me a holler when you decide to build it. I'm in Winston too and would be glad to help you out when I can. I do commercial and some residential roofing so I can help with any questions you have regarding that as well.
 
I'm fixing to build a carport with 12' centers. It will be a 24x16x10 using 6 6x6 posts 2x10s for the headers and 2x4s and 1x4s for the roof with tin. Check out my thread operation man cave build for a few references.
 
thought i'd give my 2cents since i passed inspection the first time on my shop..22widex32longx10tall shop i built by myself from scratch...4x4 on 4ft center but inspector said 8ft centers would have been ok, double 2x4 top plate was fine with him, homemade trusses i did myself with 2x4/plywood/glue/8penny nails 24"OCenter, Tin roof,. Materials for framing, roof trusses, plywood for roof was 900ish and then additional 890 for tin roof and passed inspection here in Boone NC first time for a "pole Barn" classification. i know everone says 6x6 and 6x8 but save your money and just use 4x4 and 2x4 for roofing and top plates. worst part was the darn concrete slab so freaking expensive, lol. good luck on your build
 
i would highly reccomend doing trusses with plywood and glue...way way more durable than the ones preordered with the cheapo gussets. mine is 7/12 pitch and put them up myself with 2 latters spanning 22ft wide no problem and they were no wobble to them at all..inspector even said that's a better design than store bought ones.
 
John Fuller said:
i would highly reccomend doing trusses with plywood and glue...way way more durable than the ones preordered with the cheapo gussets. mine is 7/12 pitch and put them up myself with 2 latters spanning 22ft wide no problem and they were no wobble to them at all..inspector even said that's a better design than store bought ones.
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Any pics?
 
i can get you some tomorrow. it's the "qween truss" design basically but with 12"x12" plywood squares at each side where joined...i do admit be prepared for some time ripping plywood down and assembling...i though it would never end but I also had no air guns and when you build my size garage with only hand nails and hammer...whew what a workout but it's cool in the end to say i did that all alone...no help just blood sweat and more sweat. been 12years since i built log homes so i was pretty impressed with my results...the roof kicked my ass though putting up trusses and plywood alone, lol. I'll get you some pictures tomorrow.
 
i reread your original criteria...i'll get you detailed pics of my whole shop and if you followed close to it minus the amount of posts you could have a really cheap 12x24 pole barn. i have 6 mil plastic on side walls and gable walls are closed in with plywood and surprisingly hold descent heat for what it is.
 
roof trusses design.jpg
this is the roof truss design i did..sorry just remembered i covered my ceiling few weeks ago so can't take pictures of that but this is what i did...lots of plywood i know but u can use scrap whatever you find from job sites is the beauty of it...
 
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