Pole building posts, cement or no?

I am looking to build of pole building this spring. I have asked several people and have gotten several opinions on whether to use cement around the pole to when putting the poles in the ground.
Some say they hold moister in and rot the poles. Others say sand or gravel around the poles draw in moister. Still other say you want it to hold the posts securely in the ground.
I plan on using 6x6 treated posts.
Thoughts? Opinions?

Every wooden post I have ever seen set in concrete rot off in less then 10 years but ones set in dirt last a lot longer. As to why I do not know I just know I would not set them in concrete

I just set mine on concrete pads and backfilled with dirt. We have yellow sand here and I don't imagine it holds much more moisture than gravel. My lawn can attest to that in July and August.

I was told to dig a hole in fresh hard dirt and then pour half a bag of concrete mix in the bottom of the hole and set the bottom of the post on it and backfill with dirt around the edges. Around here in NY we have to go at least 3' below grade to get past the frost. I have had good results with this method, but I do not know for sure if it is proper.
Zach

How does this sound.

Get a guy with a large auger bit and have the holes dug 4 feet deep. Then put a 6" thick cement slug in the hole. Next, Set pole on top of the cement slug. After that fill around the pole with pee gravel. That pole aint movin out of plumb and aint gonna rot. Be sure to use the heavy CCA treated posts. I have done it this way on several decks over the years and I have had no post rot out to my knowledge.

I don't put wood in the ground anymore unless it is a hedge post. If you want a building to last you need another method.
Consider This

It will cost a little more,but put "Permacolumns"in and don't worry about it.
Permacolumn.com

Doughnut of concrete on the bottom to hold the post in, don't really want it concreted at the surface where it holds moisture. Use a barrior - shingle, plastic slip, etc - if you are concreting there. Sure don't want the whole hole filled with concrete around the whole bottom of the pole.

That's in MN clay soil.

--->Paul

If you dig a hole it's usually larger at top than bottom. Thus if you fill with concrete and you live in cold climate the frost will lift the post out of the ground. Not good for a pole barn.

I just took down a building that was built in 1990 with the poles set in concrete. I pulled the posts up and broke the concrete off and the wood was in perfect condition.

If you get the properly treated poles and not the stuff with the "light" treatment that many lumberyards stock - it's not going to rot regardless of how much moisture gets in. People who complain about wood rotting are the ones who did not take the time to get the right poles to start with. In some places, it has to be special ordered. If in doubt, read the treatment label and call the phone # on it for more info. The salesmen in the lumberyards often are clueless on the subject.

Main issue with concrete is frost. You don't want concrete above the frost line unless it's a continuous column of concrete all the way.

Originally/historically - the main gain with pole barns was the fact that the poles were tight vertically in the ground and therefore eliminated the need for collar ties when roof rafters were used. Rafters push down at the peak and spread out sideways on the side-walls. Frame walls with rafters require collar ties to keep them from leaning over. Poles tight in the ground resist that sideways force. Now, if trusses are used - that sideways forces is not an issue. So, many poles are put in sloppy (in big holes and back filled).

All depends on what your plans are. Small holes dug by hand and poles put in tight work very well. I do all mine by hand but I'm an oddball. Many people today want to use heavy equipment to do all the work. Poles put into bigger holes work OK if a good concrete collar is poured around it as long as it extends from below the frost line to above ground.

Like I said before - if you are using trusses on the roof instead of individual rafters - side thrust on the sidewalls won't be an issue so the poles don't have to be near so tight in the ground. Even then, concrete pads are often poured at the bottom of the hole - often 2 feet in diameter or more - to keep the poles from sinking over time.

I just built a two story pole building and code required 3 foot diameter pads that were 6" thick under each pole, five feet below ground. That was in the New York Adirondacks where the frost line is 5 feet down.

never set the bottom end of the post into concrete.
you can set it on cured concrete, or on gravel with concrete around the post.This will always allow moisture to wick out of the bottom end grain. If the post rots or not then its due to the type of wood, sapwood or heartwood and amount of preservative.

you could set a pier with an anchor and attach the post above the ground. but I have seen the post protectors (plastic sleeve on the end of the 6x6) work if they are allowed to drain by setting the end of the post in pea gravel and cementing above the drain of the protector.

I throw the dirt from the hole into a wheelbarrow. Then I dump 1/2 bag of cement in the bottom of the hole. Line and plumb/brace the post, then mix the other half bag with the dirt in the wheelbarrow. Tamp that in in 2" layers and it will set up so solid the post will ring when you tap it with a hammer.

Setting a properly treated post in concrete should not cause rot. But that doesn't mean it is the proper way to do it.

The post needs to be sitting ON a concrete plug so it can handle its load. Dig your hole at least ten inches deeper than you intend to set the post, and at least ten inches in diameter. Then pour concrete to bring the hole up to where you'll set the post and let it cure. Set the post on top of the cured pad and back fill the first few inches with pea gravel. I like to pour about half a bag of dry ready-mix on top of the pea gravel, as it will "lock in" the post. Then back-fill with dirt.

Don't remember who came up with it but 3 years ago up north in Mich, we did a pole barn. Dug post holes and dropped whole intact bag of cement in each one. Idea was cement would hardent and be a base for each post. Comment please. It was new to me. Dave

Dirt expands and contracts with moisture. You put concrete in the hole and the ground contracts the dirt will loosen around the concrete just like it would around the post. I use pea gravel. when the ground contracts the pea gravel will settle in keeping post tight. Works for me.

BarnE, that's how I've always done it. The dry ready-mix olds the post in place better than wet, and sets up in a few days. (More like a few hours around here.)

Concrete for pad at bottom of hole only. Or, big flat rock.

I used a rather dry mix of concrete in the bottom of the hole for the post to set on, then a pin through the post 6" from the bottom sticking out both sides, then drop the post in and aline, then 12" normal wet mix concrete. Was told that under some wind conditions the wind could lift a pole building and doing it this way would prevent that.

Decay needs oxygen, it's hard to get oxygen at the bottom of a post in the ground. Posts rot off at ground level where they get both air and water.

Dusty

Built with sucess and future confidence as follows:

1. Piers were all concrete below ground 48" and above to 6x6 posts.
2. 1/3 of 55 gallon drum as base footing with key and 5' rebar in center.
3. After footing cured. Atop of footing a 12" Sono tube aprox to 12" above grade with a small channel set into the top of the concrete post to anchor the 6x6 to. assure by water level/transit that all piers are level etc.
4. Atop of concrete posts two P/T sill plate then atop sill plate the 6x6 not P/T.
5. For the concrete posts I sent into the Sono tubes at the very top a 1x6/8 to get the edge of the outside of the concrete flat or at a 90 degrees to get a nice flat surface for the side board "kick plate" to rest against.
6. My grandson will enjoy my barn! Not a fan of P/T even .6 stuff seen it rot!

I have built a few pole barns and always use concrete around the posts. Where I differ from others is that I paint the bottom section of the posts with tar. I put them on saw horses to do this. The first treatment I thin with gas to let it soak in better. I usually do about 3 or 4 coats. I have had very good success with this method. Ellis

Eric in IL had a good idea with the Perma-Columns.
They are made with high strength reinforced concrete. Easy to use for barns and decks,or any place you need a pier. Also don't expect PT lumber to last like it used to. The newer treatments do not last. We see a lot of partial decayed ground contact P.T. Some with insect damage.

D.B.

hi all,
I built a pole bldg awhile back to put my backhoe in. I put a concrete column in on a 30" square by 6" thick footing. The column form was 2x8. They were 3 ft long being 2 ft to footing and 1 ft above ground. I put a rebar in each one vertically but left it a few inches from the top. I used 1/4 in by 2 flat bar in the cement to bolt the post to. It worked out perfect. The columns were anchored to 2x10 exactly parallel like a curb on each side. Metal roof fit perfect. Just how I did it! edward will

Down here we don't have a "frost line" so you don't have to deal with that consideration. Once every 10 years we will get down to 10F for a few days and the ground will freeze down a couple of inches and that's about it.

The soil is heavy clay and there is a tremendous amount of soil activity as a function of water content, or lack thereof. On T posts, the ground dries out, cracks open, the T post sinks, rains come and seal the post just to repeat the process annually. You have to have line posts about every 100' that are large diameter and set in concrete to hold the fence up when the ground cracks open. Buildings, at least perimeter poles are the same way.

I have a pole barn that I built 30 years ago without concrete anchored posts and the bottom of the trusses are about 2' closer to the ground than they used to be. The poles just sank.

On concrete anchored poles, we usually set the poles in the hole and add the concrete after we get them lined up. In this fashion the bottom of the pole is sitting in the soil and resists deterioration very well.

I was short on funds when I built that barn or I would have anchored them in concrete. Barns since then have been concreted and I can't attest to any sinking problems.

HTH,
Mark

Moisture? Well my boat dock was built in 1988 with treated posts and they are in water 24/7/365. They still support the roof and my boat hanging from a hoist.

Is there a local code you have to comply with?

Friend of mine put up a barn here in West Michigan and the inspector was all over him about the proper installation of the poles. As I recall he had to do either 14" or 16" holes for his posts so he could get sufficient concrete around them.

This would be Fruitport Township where they have a reputation for making it difficult.

I don't know one way or the other, but I got to thinking about the reason for cement. Is it to keep the pole from settling or from pulling out of the ground? A lot of us have seen pole buildings blown away by tornadoes and how many of them have the poles pulled out? Most snap first. I have seen a corner settle on a Morton building, where the corner pole was set over a big old tree stump that rotted. If the ground is firm where the building is setting I wouldn't think cement would be needed. Just drill a hole through the bottom of the pole and stick a re-rod through it for an anchor.

When Dad's Morton was built in the late 70's they dumped a couple of bags of dry cement mix in the bottom and tamped in the dirt on top of it. I don't know if it rotted or not, or if it matters if it rotted off three feet below grade. Jim

All good advice here. This is just a shed, not a big pole barn but as you can see I will not put any wood in the ground.

4" x 6" untreated pine posts sit on the concrete filled sono tubes.

I suppose it could become airborne in a hurricane so I might add some strap anchors someday. It"s been up 9 mo. now. Never moved yet.

I'm still using a few pole barns I built 40 years ago. No rot - but to be fair - the wood I used back then was either creosote or CCA treated. You're not likely to find poles with that treatment now since they are now allowed in exposed-residential work. ACQ is more the norm.
You have to be very careful to get poles with the correct long-term below grade treatment. Many do not. I like pole construction because I always work by myself. No helpers. I built all of these alone -with help from my backhoe.

Here's an addition I built on a house 20 years ago. 6"X6" poles for the first floor and 2" x 6" frame construction on top of the poles for the 2nd floor. It was a tough job since I saved the old dug well that had been in the "back yard" and is now in the house-kitchen. No concrete pads under these poles because I hit hard shale 4 feet below grade.

The laid-up stone well has the blue tarp over it.

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Framing the floor around the well . .

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From a distance . . .

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Getting the walls on . .

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Close to done . . .

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Well inside the house - in what became a big kitchen, along with a Rumford wood-cooking fireplace and bake-oven.

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Here's a pole barn with two purposes. One roof with a special angle to hold solar panels and the rest to hold farm and construction equipment. These 6" X 6" poles are on 2' diameter concrete pads.

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This is a four-story barn I built 30 years ago. No rot anywhere. 6" X 6" directly in the ground. Some with concrete pads and some with not if hard-pan was hit. Pole construction first level, and 2" x 6" frame above. Three full floors and fourth just a small bedroom.

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Here's the one problem - I built in the trees and tried to save all I could. This ash "sapling" has grown right into the roof and I'll have to climb it and cut it down soon.

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Here's a two story pole barn I just finished in the NY Adirondacks. 6" X 6" poles on first story and 2" x 6" frame on second. Roof is all 2" x 10" rafters (no trusses). Built it right over an old camper trailer so we had a place to say while working there.

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Just talked with my contractor a couple days ago and he said two bags of quickcrete in the bottem of the whole, 4 ft deep (frost line in New York), and backfill with gravel. Where I live in upstate new york, we have barns that are still standing 100+ years later and those that are falling in are not because of the 6x6's, its the roof structure that is failing.

i'd dig the holes and drop the poles in. if you like you can drop a pillow block in the bottom.. but I personally wouldn't add cement.

the poles inthe ground are technically 'friction piles' side load makes them difficult to pull out..

google friction pile for more info.

Mind you.. I'm not in your area ( indiana? ) though I'm civ eng here in florida.. etc. no frost line to deal with.. thus no heaving.. etc..


soundguy

In SW Ohio a 6x6 will last 15 to 20 years tops dew to the moisture in the ground. Now all the companys that built pole barns are having to replace posts now big time. When we built our new 40x60 we went with the Perma-Columes concrete posts and composite (plastic) boards around the bottom and so far so good. The cost is worth it in the long run. Just something to think about. Bandit

If their treated poles are rotting out in 15-20 years - they are using poles with inadequate treatment. Not every company cheaps out and uses inferior poles.

By the way, I just built a bridge out of utility poles that were recently pulled on my property. They were put in the ground in 1948. Still pretty solid. That's why I told the power company to leave them behind.

LJD, love that pic of the kitchen with the Rumford, cookstove and well! Good job!

the key to preservatives is the retention it is treated to.Home Depot crap is treated to about 0.4 PCF of CCA or QCA. We always specified 1.0 PCF for above ground retention and up to 2.5 for in ground in wet soil or in water. Creosote if it is allowed in your state should be 18 to 22 PCF for extreme conditions.The PCF is determined by sample cores taken in the assay zone which is generally the sapwood. We have lumber suppliers that will supply treatment certifications for the PCF we require.
We also have independent testing labs that will take sample cores in the field to verify the certifications--not something that the average home owner can afford--but once we are satisfied that a supplier is honest we can assume that his certs are correct.

think about this,when you want a hole to hold water,such as on a septic system you fill it with rocks.well putting rocks and concrete around a pole does the same,except in reverse.it will hold moisture that normaly would be in the soil.a french drain or tiling does this,and drys the ground out.Electric company doesnt cement its poles in, simply because they last longer. ive seen a lot of tornado damage over the years.Honestly i cant say ive ever seen a properly set pole on a barn pulled out of the ground with just dirt around it.my opinion of course.