Not an expert on pole barns but IIRC the poles a sunk far enough so that they provide the lateral shear strength. That means they have to go in
3' to 5' depending on how big your building is. Plus you may need to pour a concrete 'collar' around each pole.
A good gravel base will work fine until you get enough extra $$$ to pour the floor later. Make sure that you grade things, set the collars, set the driveway, etc so that it all works out right for the later concrete.
There are lots of suppliers that will create a plan, sell the materials, and deliever to your site. In the midwest Menards is one of the bigger suppliers, each of their stores has a kiosk and computer to let you design what you need.
For residiential area build> Thinking of building a pole barn shop about 24x32. Have to do by
Your posts is what keep the building from blowing away in a wind storm. If you live where there's no hurricanes, tornados, or severe thunderstorms you might be OK. For my barn, the posts are four feet deep with a 12" concrete cookie for the posts to rest on. The cookie has rebars in it that are stapled down to the posts. The cookie will cost you $10 a pole extra, but now the weak link is the building shaking apart, not coming out of the ground.
There's tons of places that offer complete building kits. Much better than buying the parts al la carte. Nearly every lumber yard and big box home supply around offers a kit.
On 2 Jun 2005 13:11:23 -0700, the inscrutable email@example.com spake:
Get thee to thy library and pick up Monte Burch's book. It's a great resource.
Monte Burch's Pole building projects : over 25 low-cost plans Book Author: Burch, Monte Publisher, Date: Pownal, Vt. : Storey Communications, c1993. ISBN: 0882668609 - Description: vi, 200 p. : ill. ; 29 cm.
He also wrote a couple books on barns and outbuildings.
-- "Not always right, but never uncertain." --Heinlein -=-=-
I live in Kentucky. Mostly line stone and clay around here. What I am afraid of is running out of headroom by the time I put a 4x6x12 3 feet deep plus the gravel to level it out plus the concrete later.
The pole barn my friend built some years ago was from a load of power poles.
Sold off the power company manufacturing lot. He dug 4' holes and hand set the poles by himself! - No rigging.
He dug the hole. Then slotted in one side - long gentle slope to the bottom. Then the pole is rolled so the end is near the hole - pole bumps down the slot and starts to stand up - Once planted, he walked up the pole - standing it up and then he tied it off to his tractor and filled/ packed the hole.
Typically the power poles are only 3-4 feet deep - once packed that is strong.
Call your local power company and see where they are replacing poles. My neighbor now is the proud owner of a stack of poles that were formerly holding up the wires on our street. Can't beat free and you can cut them so you have plenty of headroom.
I use a slightly different technique. After I drill the hole I put the pole across my carry-all. If you get the post positioned right on the carry-all and the carry-all at the right height (experience), then it is EZ to lift the pole since it is nearly balanced and when you flip it up it falls down in the hole so neatly I usually don't need the board to keep it from digging in the side as it goes down. I have erected telephone poles over 20' high singlehanded.
Yeahbut... (my life is dedicated to the "yeahbut"), because of unfortunate indiscretions by owner-contractors over the years (like burying posts only
2' deep), most juridictions' code now requires more than just a "bit" of concrete for pole collars.
My next-door neighbor screwed the code for the whole county. He basically built a barn on hinges (metal post anchors screwed down to his slab). One fat downburst later, the barn was on the ground (with the roof in entirely one piece!), and the county revised the code for all agricultural builders.
Now, we have to go through engineering to even build a two-horse pasture shelter! Our local code requires posts no smaller than 6" and no less buried than 4' - regardless of the size of the barn - and a minimum 18" diameter by 12" deep collar with cross-pinning in the collar and through the post of #5 re-bar or equivalent.
That's WAY overkill; but because too many people did it half-assed, we all have to follow a code that is unreasonable (not to mention expensive, to get engineered, certified drawings from an architect).
Nope, not unless the concrete footer is at least another two feet deeper. You _NEED_ at least four feet in the ground to give you the lateral load resistance required. (unless you're talking about a continuous footer around the whole periphery of the barn. But then it's not _quite_ a "pole barn" anymore.)
What Lloyd said. When mine was built, the holes were about 5' deep and the contractor just poured a bag of dry ready mix concrete into each hole before the poles went in. He said the moisture in the ground would set it up and it would be plenty of foundation for the bottom of the poles. Had no reason to doubt his method, as he'd built many, many poles barns in that part of Southern Indiana with no history of problems.
My Morton building used pressure treated 6x6s made up from three 2x6s nailed together with a with about 12" of rebar crossways IIRC 6" from the bottom. They used a tractor-mounted auger to punch holes about 18" in diameter and
5' deep for each "pole". They dumped one bag of Sakrete in the bottom of the hole, then placed the pole and added a second bag. The hole was then filled with dirt. Ground moisture did the rest. Then there was the 5" concrete pad that held them all down 8o). Take great care to tie things together to prevent wind from lifting the shed off/out of the ground. Thunderstorms/microbursts can really suck things up out of the ground.