Installing post in a pole barn

   / Installing post in a pole barn #1  

ch47dpilot

Gold Member
Joined
Mar 26, 2010
Messages
258
Location
Ozark Alabama
Tractor
07 Kubota L3400
I'm currently starting the layout for a 24x36x14 pole barn. Here in Alabama the roof trusses are made from steel not wood(Dixieland Metals of Dothan Alabama - Manufacturers of Metal Roofing and Siding). The manufacture includes about 4 bags of ready mix for each pole. From the threads I've read here everyone says that concrete isn't good for back fill and it should be loose material, ie gravel, dirt ect. I have a few questions that someone could maybe answer.

1. Are we talking about treated or untreated post when people say they will rot in a few years if you use concrete in the complete hole? A book i bought says the complete concrete encapsulation is best to maximize side loads but they never talk about it reducing longevity.
2. Everyone seems to think the best way is to first lay about a 6' layer of concrete first before placing post in hole. If you first let the pad cure won't there be issues with the cold connection between pours. I would think water would wick between the 2 separate pours causing faster decay. If so is there anyway to minimize this? I was think of something like pour the pad dry, place pole in hole then wet just before I do the second pour, which would be mixed prior to going into hole.
3 To help protect the pole below grade has anyone heard or seen of using something in addition the the factory pressure treatment. I would think something like a roofing tar, waterproofing paint, or even some of the do-it-yourself bed liner would make an excellent protectant provide it adhers to the wood.
 
   / Installing post in a pole barn #2  
Here in FL - For my 28x22 barn, which started life as a pole barn until I closed in the sides with plywood & 2 garage type doors, I set my treated 4x4s in 3' deep holes, then filled the holes with quikrete. It's only been about 10 years, but no problems so far .. and I will say that my insurance co (State Farm) came out to inspect it, we discussed the 4x4's in the concrete like that, & they insured it & still do; Must be OK.
 
   / Installing post in a pole barn #3  
i used 4x6 presher treated posts on my pole barn the post rest on a concrete pad backfilled with dirt.
 
   / Installing post in a pole barn #4  
Even bus drivers are welcome here ;)

What you are bringing up is one of those questions that get debated till the ends of the earth and nobody seems to have any positive answers.

Mine got concrete. My best friends did not. Seen them done both ways, and seen them rot both ways, and still stand both ways.

The layer on the bottom is to keep the post from sitting in water is the general theory, but that depends a lot on your soil and water table. I like at least 6" of rock or a paving stone or such on the bottom when I do them.

I think (believe) all the things mentioned can only help, I did not do anything like that on mine though.

The single biggest thing I would suggest is to make sure you get the right (most) pressure treated stuff.

I probably have the numbers names wrong but the scale will be about right. Most PT you buy will be .4 pt. That is what you will find at Lowes etc. and most lumber yards. The folks doing pole buildings should be able to get you .6. Don't let your kid chew on it, donate it to make a playground, or chip it and turn it into mulch for the wifes flowers, but if you want it to last a while, that is the one you want stuck in the ground.

Good luck, I have a similar style building.
 
   / Installing post in a pole barn #5  
Although I think my existing barn described above is fine ... I've considered for my next, upcoming barn, pouring a concrete footer for each post & embedding a galvanized steel post holder/ bracket into the concrete, so the posts never sits in dirt/ mud/ water. I haven't checked to see what the strength of these is; i.e. Would a barn built this way be sufficiently strong?
 
   / Installing post in a pole barn
  • Thread Starter
#6  
Alan B: Some people can drive a bus because they don't need to make up for their short comings(sorry Attack guys)
 
   / Installing post in a pole barn #7  
My 40X45 pole shed/barn was installed in 1992. Have not had any problems with the posts moving or heaving.

The installers drilled 48" deep holes, poured a 6" concrete pad and let it cure over night. The next morning, they set the posts and backfilled around them with 3/4"+ gravel (known in some parts of MN as "sewer rock" for reasons unknown). The soil type here is heavy clay. The gravel backfill is to prevent the clay from grabbing the post and heaving it up when the ground freezes over the winter. It also allows for drainage of any water that may collect around the post from rain water run off.

As others have mentioned, the "correct" way will be dependent on your location, soil conditions and freeze/thaw cycles.
 
   / Installing post in a pole barn #8  
I think the correct way is the way you are most comfortable with. My posts are .6 Pressure treated, with 20" round, 8" thick concrete footers underneath, and then I tamped dirty stone around the posts. Footings under the posts are for bearing load, the size is based on soil types for your area.
 
   / Installing post in a pole barn #9  
Just curious what are they charging for your pole barn kit? I went too their website and the only price I saw was pole barns starting at $1199. Just wondering what came in their kit?

I tried calling but not their or having somekind of problem with their phones!
 
   / Installing post in a pole barn #10  
If you are worried about rot get your PT post from a treater. Get the 60 year treated post the same that is used for docks and bulkheads put conc in hole first then set post plumb and encase them in concrete you will not have to worry about water exposure or rot!
 
 
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