Pole barn foundation

[LastSTRAW]

And Hay shouldn't be an issue either if you are storing it on the ground. I have a 40' x 50' pole barn and I am not even sure if the posts are in concrete or just planted real deep. The hay is stored on the ground and it works just fine. Wish I remember what was used but I was 10 years old when my uncle built it.

 

[BeezFun]

There are no center post. No load on anything except whatever snow load might occur. I realize the tractors create no load, just stating that is part of what I would store one the building.

OK, so it's easy to figure the load on the soil. You have 28 load bearing posts. Using numbers from my first post (no pun intended), each footing is 1.75sf and the total max load with snow and building weight is about 270,000 pounds, so the load on each footing is 270,000/(1.75*28) = 5500 psf. That's quite a bit higher than any soil wants to support, clay is about 2000psf, good gravel is about 5000psf. I don't know what the design snow load is in your area, you might find that out to get a better number. I would not let this concern you, as I said before my experience is that pole barn footings are generally underdesigned but you don't see any falling down. I'm not sure how they distribute their load in the real world, maybe they're all trying to push the skirt boards and siding down into the soil and that helps resist the loading.

In any case I'd still vote for standing your ground that this is an ag building. You might try talking to whatever form of elected official you have, the building dept lives under some branch of government and will go away if the right politician is convinced you qualify for an ag exemption.

 

[superduty59]

In your first post you said you didn't need a permit. Now you do? I too live in Ohio and my county doesn't require a building permit.

 

[Maynard Reece Byrd]

Doc,

Trying to get a handle on how the footings are constructed. I am guessing from your description that the top of the concrete footings are even with the ground and the 6x6 attach to the footing at ground level. If this is the case was the concrete poured in a hole dug with an eighteen inch auger? If this is the case, do you know if the hole might have been bell bottomed(widened out by hand at the bottom)? Many times in my area the bottoms will be widened which gives a larger bearing surface on the soil and also provides an anchor to help prevent the footing from being pulled out of the ground in uplifting conditions that can occur in high wind situations on the structure.

 

[superduty59]

Doc,

Trying to get a handle on how the footings are constructed. I am guessing from your description that the top of the concrete footings are even with the ground and the 6x6 attach to the footing at ground level.

Not trying to hyjack this thread but I'm in planning stages of my 32x40 2 story pole barn house. I'm trying to find the most economical way to obtain adaquete footings. Perma-Columns are great but at $108 ea out of my price range. Post Protectors at $35 ea are a better price.

What I'd like to do is dig my holes 24" diameter x 36-48" deep and fill with rebar, and concrete. Only 5.5-8 yards of concrete.

1)What would be a good way to attach post to concrete footer at ground level? Thus avoiding treated 2x6 laminated posts.

2) Anchor steel post connectors in concrete while concrete still wet?

Thanks!

 

[Maynard Reece Byrd]

A quick web search found this and I am sure there is a lot more some searching would find.

http://www.awc.org/publications/dca/dca5/dca5.pdf

I have seen several options employed on post frame buildings. I have seen mostly direct buried post, either a solid 6 x 6 pressure treated post or a laminated post made from three pressure treated 2 x 6's. I have seen some of these posts set on a foundation pad(pre-cast concrete pad about 15" in diameter and about 4" thick) that are placed at the bottom of the hole. The post would have cleats nailed on the bottom. These cleats do provide a bigger foot sitting on the foundation pad, but an important function is to anchor the post in the ground and resist uplift forces. In a strong wind the wind load on the side of the building wants to roll the building over. A smooth post in the ground with no cleats at the bottom provides little resistance from being lifted out of the ground, therefore, the building could roll over and blow away.

I have also seen buildings where holes are drilled in the bottom of the post and 1/2" rebar driven through the post and the hole filled with dry concrete mix.

I have seen concrete pier used with the bottom of the pier below frost line and an anchor base embedded in the concrete and then the post attached with a bolted connection.

There are a lot of variables across the country with varying snow loads and wind loads. The bearing capacity of the soil can vary widely even within your local area. I would say local contractors, building suppliers, post frame builders, ready mix concrete suppliers or the county extension office might be of help.

In my area of Kansas I see a good number of post frame building constructed and many times the reason they are chosen is because there is less concrete involved, therefore, less cost. Sometimes the thought is to get the building up with a dirt floor then when funds are available put in a concrete floor. Many times the pressure treated skirt board is used as top elevation of the floor and the concrete screeded from the top of the skirt. One problem that some have in this area is that rodents really like to live under the concrete floor, especially if the owner decides to put floor heat in the slab.

One other issue that should be addressed on metal sheeted buildings is insulation and condensation. If moist air can get to the underside of the roof sheeting there can be condensation or frost on the underside of the roof metal. This condensation can start dripping or in the case of frost the heat from the sun might melt it or if you fire up some heat in the building melt it and start dripping. To avoid these issues it is common in my area for insulation to be laid over the purlins before the roof metal is attached.

 

[BeezFun]

Doc,

Trying to get a handle on how the footings are constructed. I am guessing from your description that the top of the concrete footings are even with the ground and the 6x6 attach to the footing at ground level.

OP states: "on poured concrete that is 18 inches diameter by 12 inches thick 36 inches deep". So the top of footings are either 24" or 36" below grade, depending on how he measured the 36" depth. I'm guessing he meant the bottom of the hole is 36" deep, so the top of the concrete is 24" below grade.

 

[mojoinco]

Not addressing the use of the building, but the tax assessors status of the use of the property versus the zoning of the property. In my county in CO the assessors status of the property use can be very different than than its zoning. I have 10 acres zoned ag, but I haven't used it for an agricultural purpose to apply for ag property tax status. Folks that do it often have to wave an attorneys letter head under the county's nose to get the exemption (when a less than 35 acre plot sells they are changing its status to large rural lot to keep the tax base up and any opportunity for ag tax status). Developers and speculators do it all the time (when horses or cows show up to graze all of a sudden -- even while building that is clearly not ag is occurring, you know what is happening).

Back to the building permit: did they say you needed the building permit due to its use, or due to the tax status of the property? What is the verification process (that you are using it for an ag purpose; if there is a verification process)?