Pole Barn Foundation Size

[tlmartin84]

What size do you all typically dig for the pole foundations?

I am comtemplating a couple options.

Pour footings with concrete and insert anchor bolts with a base plate for a 6x6, and go up from that to eliminate wood below ground, shorter post are cheaper as well.

Then there is the standard placing pole in ground and filling around it.

I just don't like the thought of termites and rot, but at the same time I am not sold on the structural stability of the plates on foundations, mainly due to wind concerns.

 

[Highbeam]

When you build a fence you depend on the fence post's lateral strength to prevent the fence from blowing over. You bury the post not 6" but a couple of feet. The idea is that the post would break before just falling over.

I agree with you that a bracket can never take the place of a full four foot bury on a pole used for a pole building.

I was required to go 30" diamter and four feet deep. On the bottom I poured an 8" pad with rebar, then set post, then backfilled with concrete. In the backfill I had to stick (18" deep ) 5 foot long bars of steel which were bent over and poured into the floor slab for even more lateral strength.

 

[rburke65]

Just finished a pole foundation....holes were 54" deep, with 6" of concrete.....so 48" in the ground. Maybe ? 20" in Dia.

 

[cyamaha2007]

On my build i went with a 24in hole with a 8in footer 4feet deep. I did not surround the post with concrete. I filled the hole with chat and tamped in the post.

 

[kbs2244]

All you need to know

http://www.pole-barn.info/pole-building-construction.html

 

[mkbrower]

When I built mine, the building code specified a 36" X 18" hole, 12" footing. The building inspector said pour a 80lb bag of concrete in the hole, place the pole in the hole and pour another 80lb bag around the post. He told me to pour it in dry and the concrete would absorb the moisture from the ground and will be harder than if I mixed it before I poured it. The link above shows the use of a pre-cast pad. I bought these to put in my holes but when I told the building inspector my intention of using these, he told me pre-cast pads were not allowed. It would be wise to check the codes in your area before planting your posts.

Mark

 

[tlmartin84]

I think thats a bunch of BS.....the precast vs non-precast, he is also BSing about dumping it in loose and it getting harder.


Speaking as an engineer and someone who designs concrete structures for a living, concrete is concrete whether its precast offsite and placed in a hole or poured onsite as long as prep work is done to ensure no voids under the pad and that the mix design is the same.

And at no time will loose concrete dumped into a hole harden harder than concrete mixed in a plant with the correct design mixture.

Some of these local inspectors really rub me the wrong way.

 

[tlmartin84]

Now I have to dig out my copy of the IBC to see what it has on this matter......our guys are pretty good about negating the local adopted code if it is signed off by a licensed engineer.