Pole barn posts

[budman72]

Getting ready to start a pole barn but not a level site on my land so the barn will be build on a "cut & fill" site. the fill part will be 2 - 3 feet deep. Can the poles be set in the fill or should they be set in virgin soil. If not, will concrete piers work? The barn will be 24 X 36, 10' eaves with room for the 4200, my 67 MGB and a workshop. If I put in a toilet and refrigerator, who needs a house? Come to think of it, I really don't need the toilet!

Bud

 

[Slamfire]

The poles ought to reach soil that never freezes. That is usually described as so many feet deep. If you filled the undisturbed earth would still be so many feet deep.

 

[WVBill]

I would not have wanted to sink the posts for my pole barn in fill without getting a construction engineer to specify the required compaction and depth. From the books I read on pole buildings before I built, the type of soil makes a big difference on the weight bearing capacity of the pole and stability of the building.

 

[gws]

A 24x36 is pretty small for a tractor, car and a work shop. My stable is 24x36 and I would hate to try to get all that in there and still have room to do anything.

 

[rdln]

I had a foot of topsoil removed and four feet of clay added and packed during fill. I paid $600 extra to have about 40 posts sunk an extra foot to make sure I was well into undisturbed earth. The area was too flat and I wanted good drainage and better aesthetics. I wouldnt hesitate to go the extra mile too have your footings on virgin ground.

It Sounds like you will have part of your floor below grade?

 

[SteveBenson]

I'd definately go down to undisturbed soil. I was talking to an excavator recently about fencing and he told me he backfills all his fence posts with stone dust instead of native soil. He said it provides good drainage around the post and the stone dust locks up better than any soil ever will when tamped. Sounds like a good idea for barn posts too!

 

[WVBill]

That's an "ongoing discussion" about pole buildings too. Some say that tamped soil (or stone dust) is better than concrete. The counter argument is that the weight bearing capacity of a pole building post is proportional to the surface area of the post that is in contact with the surrounding soil. So if a post is anchored to a surrounding column of concrete (e.g. by protruding spikes), it's the surface area of the concrete "post" that determines the weight bearing capacity.

I don't know the answer, but I have seen a whole lot of 200 year old pole barns still standing where the posts were set in tamped soil but I've never seen a 200 year old barn where the posts were set in concrete. /w3tcompact/icons/wink.gif

 

[pajoube]

Is stone dust just what it sounds like, ground up stone?
PJ

 

[pajoube]

If you were to set the pole on a cement footing would you then still have the same problem? Or is just setting on tamped soil as good or better?
PJ

 

[gerard]

Stone dust is made from the "fines" that are left over after running bigger stone through the crusher mill to get the various sizes. Kind of like the "runner crush" but after screening and no large pieces. It's really almost a really course sand. re putting the post on concrete that would be fine as it would distribute the weight over the surface area of the concrete. That ALL has to be below the frost line for your area or you could get heaving. The more compacted the soil everything sits on the better. Virgin earth is usually preferrred because due to time, the weight of the soil over it, and water infiltrating through it over time, it's usually pretty well compacted. If you build right on fill without giving it time to settle you WILL get some settling which is about the last think you want after spending all that time lieviling everything!!