Anyone Familiar with Pole Sheds?
Anyone Familiar with Pole Sheds?
(OP)
I have been asked to design the foundation for a pole shed. They said they typically dig an 18" diameter hole, drop the 6X6 wood post in, and pour it solid with concrete half way up.
I have a couple of concerns.
1) is it okay to bury treated wood in concrete?
2) will the concrete bond to the wood to resist uplift? Or, should I have them leave some bolts sticking out of the side of the post to "grab" the concrete?
Also, are there any other issues I should be concerned about? My plan is to design the post and footing as cantilevers, cantilevering up from the ground, and the framing will be by the building supplier (I was not asked to review the framing above grade)
Thanks so much for your input!
I have a couple of concerns.
1) is it okay to bury treated wood in concrete?
2) will the concrete bond to the wood to resist uplift? Or, should I have them leave some bolts sticking out of the side of the post to "grab" the concrete?
Also, are there any other issues I should be concerned about? My plan is to design the post and footing as cantilevers, cantilevering up from the ground, and the framing will be by the building supplier (I was not asked to review the framing above grade)
Thanks so much for your input!






RE: Anyone Familiar with Pole Sheds?
As for the concrete, I commonly pour the concrete to the top of the grade, and yes, treated lumber is embedded in pole footings all the time.
Just use the equations in the IBC to determine the proper depth, based on the soil type, and whether or not there is a slab present.
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Anyone Familiar with Pole Sheds?
Yes - treated posts are typically buried about 48'' into ground with and without concrete. I usually use a couple #4 rebars drilled through the post to "grab" the concrete or earth. Note that the post might deteriorate at 20-30 years.
These building are not meant to last a lifetime.
Size of hole depends on post(truss) reaction, wind and soil values.
The cantilever design is very conservative but good. You might be disappointed with your results - depending on building size and height. You can(might) get some shear help with the metal cladding.
Check out National Frame Builders (NFBA.org) I think and anything written by Frank Woeste or Stan Suddarth.
There a many companies that do this every day - like Morton, Wicks, BBL(Missouri), Borkholder (Indiana), EPS(Iowa) etc.
RE: Anyone Familiar with Pole Sheds?
Thanks again for your help, I will look into the references you suggested. If you or anyone has any other input/opinions, I'd love to hear them.
RE: Anyone Familiar with Pole Sheds?
Brad
RE: Anyone Familiar with Pole Sheds?
I typically specify my embedded posts be treated to AWPA Category UC4C.
RE: Anyone Familiar with Pole Sheds?
I have a feeling that many a client has been unhappy with a structural engineer's actual design of such a structure. I imagine the initial client meetings are like- "well, what we usually do is _____, and that's been working for ____ years now.... Why the hell you need so much darn concrete and all these fancy connections?"
RE: Anyone Familiar with Pole Sheds?
RE: Anyone Familiar with Pole Sheds?
I think I'm going to have to bite the bullet and buy their ASAE 486.
If anyone has any other input, I'd love to hear it. There are a ton of different foundation types so it's helpful to hear what people have had actual success with in the past, and perhaps not-so-good success with.
Thanks!
RE: Anyone Familiar with Pole Sheds?
If you are treating southern yellow pine, there is no difference in treatment levels between UC4B and UC4C other than ACQ is not allowed for UC4C. The posts I have been using have all been special order, (ever seen a 14"x14"x18' SYP post? Maybe that isn't a post when they get that big!) so I am guessing specifying a different treatment level other than 0.60 pcf of CCA is likely not going to be considerably more money. If you are trying to use something locally available, you are likely going to be stuck with UC4B, likely ACQ preservative.
ASABE 486 is free on the ASABE website. Here is the link:
http://as
Most of my foundations have been for 40-60' pole buildings. Most posts are 8x10 SYP (snow loads in Vermont). I have been using a 30" diameter footing and 1-2' deep collar around the post with rebar pins extending into the post. Embeddment depth is typically 5-6'.
RE: Anyone Familiar with Pole Sheds?
I'm not a member of ASABE, so I don't have access to that.
Thanks for your input. One question - Do you get the bearing to check out for the rebar embedded? I haven't plugged through my calculations yet, so I'm not sure what kind of uplift I'll have, but it will probably be fairly significant because I have open walls on 2 adjacent sides. Or, is there some sort of calculation for the bond the concrete might have with the wood?
RE: Anyone Familiar with Pole Sheds?
RE: Anyone Familiar with Pole Sheds?
RE: Anyone Familiar with Pole Sheds?
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