Pole barn post question

[jimpad]

I'll soon be building what we locally call a pole barn.  The practice around here is to sink pressure treated posts into the ground four feet.  I do not want wood to dirt contact in any way so I plan to bore holes, fill with concrete, and connect the pole to the concrete somehow.  Is there a generally accepted method of attaching poles to concrete which will provide the same force resistance as planting the pole in the ground?  Budget is extremely tight and does not allow for purchase of the factory made brackets or the precast pilings.

[Drivadesl]

I never built a pole barn, but, I'm planning a similar method for my saw shed which expect to complete this summer. Like you I'm pouring a concrete pier that extends above ground level, and attaching the post with ties embedded into the concrete.   I imagine you could fabricate your own brackets if not wanting to buy, though I have not priced the factory ones.

[Crusarius]

I don't know if code still alows it but a simple anchor bolt poured into the concrete is the quickest and easiest option. then end drill the post and set it on top of anchor.

This may not be up to code depending on your wind zone.

[Jim_Rogers]

Concrete 8" above finish grade would be nice. Put some metal straps into concrete and secure them to the sides of the posts.

Or use the "short pole" system.

With that you bore your hole, put a piece of PT pole in the ground, back fill with crushed stone so water will drain, and then put a regular pole on top. Sister PT on sides.

10-20 years from now when post in ground rots out (if ever) then just replace the bottom piece by holding up barn and taking out rotten piece.



 

Jim Rogers
Wood is cheaper then concrete.

[jimpad]

I never built a pole barn, but, I'm planning a similar method for my saw shed which expect to complete this summer. Like you I'm pouring a concrete pier that extends above ground level, and attaching the post with ties embedded into the concrete.   I imagine you could fabricate your own brackets if not wanting to buy, though I have not priced the factory ones.

How do you plan on forming above grade... sonotube?

10-20 years from now when post in ground rots out (if ever) then just replace the bottom piece by holding up barn and taking out rotten piece.

It's actually going to be a house so I don't want it moving around if i can help it to; minimize drywall cracking, etc.

I don't know if code still alows it but a simple anchor bolt poured into the concrete is the quickest and easiest option. then end drill the post and set it on top of anchor.

How do you then secure the anchor nut... or is the post just set on top of the bolt without fastening it to the pier?  No codes where I'm building.

How do you do multiple formatted quotes within a reply, I could only see how to do the one?

Thanks

[flyingparks]

These are about $5

 

[ChugiakTinkerer]

Might be on the too-expensive side of things, but the Timberlinx A475 is used to anchor a timber post to concrete.

http://www.timberlinx.com/cat_a475.html

There's a guy on Craigslist in Anchorage with 16 of these that he's been trying to sell for several months.  Might be worth making contact if interested, but caveat emptor and all that.

Finally, here's a project that used these anchors: http://www.frankladner.com/shedproject/

[bucksnort]

Cut the bottoms off 5 gallon plastic buckets, ( cheap sonotubes ) Half inch plate stock sunk in concrete leave enough above forms to bolt into posts. worn out snow plow blades would work or scrap yard.

[Crusarius]

How do you then secure the anchor nut... or is the post just set on top of the bolt without fastening it to the pier?  No codes where I'm building.

How do you do multiple formatted quotes within a reply, I could only see how to do the one?

Thanks

Yes. just set the pole on the rod. That is the reason I mentioned wind loads. A good wind may lift the corner of the building.

I think the $5 plate will be the best option. I didn't even know those existed. To bad I am using rough cut lumber otherwise those would be great.

[ChugiakTinkerer]

...
How do you do multiple formatted quotes within a reply, I could only see how to do the one?

One way is to open separate tabs for each message.  I right-click on the Quote link and select Open in New Tab option.  Select and copy the text you want to quote, then paste it in another tab that has the message you want to send.  It's a little cumbersome but gets the job done.

[jimpad]

I like the 5 gallon bucket idea with the 5$ bracket.  How do you hold the bucket in place... I wouldn't want to set it on the ground so I'd have to bore the hole bigger than the bucket diameter so the bucket would be hanging in space.  I can think of a number of ways to support it but any ideas on the best way to hold it in place and level it?

[ChugiakTinkerer]

The last time I poured in sonotubes I just screwed the tube to a pair of 2x4 that extended over the hole.  That works when the bulk of the sonotube is hanging below the screw points.  For a bucketube you'll probably have a top-heavy arrangement.  Perhaps a 2x4 with a plywood triangle attached to raise the attachment point higher?  Heck, just a 2x4 tee on each side of the bucket ought to work.

[bucksnort]

I like the 5 gallon bucket idea with the 5$ bracket.  How do you hold the bucket in place... I wouldn't want to set it on the ground so I'd have to bore the hole bigger than the bucket diameter so the bucket would be hanging in space.  I can think of a number of ways to support it but any ideas on the best way to hold it in place and level it?

dig the top of your hole down a few inches (4-6) the same diameter of the bucket top and set the bucket in the recessed hole lower or raise the bucket in the recessed hole  according to the grade you want. Throw some dirt around the sides of the bucket to stabilize . My uncle use to do this with ice cream containers. I would throw some rebar down in the hole before I poured all the way to the top.

[MrMoo]

I built a pole barn 10 years ago. I brought the sonotubes out of the ground about 8 inches. The carpenter just built the walls consisting of poles and perlins on the ground and tipped up the walls putting the butt of the poles (three 2x6s) on top of the concrete without any fastners. It met code and has not moved since.

[Don P]

It may have passed inspection, it did not meet code. Gotta hold the building down, prevent it from sliding or tipping and brace it. That is also the problem with dropping a post over a pin.
Here's another way, I cast some scrap with hooks of rebar in the footing, made hinges out of pipe attached to sections of reinforced I beam scrap which allowed tipping it up then welded the plates together. 1/2" lags run up 8" into the post bottom. The footing is a 2x2 square hole (a 4 square foot footprint, think about soil load) it extends 2' down to frost depth and is a 2x6 above grade, just a simple box form that spans the hole.


I use knife plates on porch posts pretty often, that would be another way


When a post frame building doesn't pick up lateral resistance from having the posts embedded in the ground it needs to get that bracing from somewhere else.

[LeeB]

Mine is just for a barn. Cedar posts straight in the ground. It will last 20 years. I may or may not last that long.  :D



  

  


 

[flyingparks]

It may have passed inspection, it did not meet code. Gotta hold the building down, prevent it from sliding or tipping and brace it. That is also the problem with dropping a post over a pin.
Here's another way, I cast some scrap with hooks of rebar in the footing, made hinges out of pipe attached to sections of reinforced I beam scrap which allowed tipping it up then welded the plates together. 1/2" lags run up 8" into the post bottom. The footing is a 2x2 square hole (a 4 square foot footprint, think about soil load) it extends 2' down to frost depth and is a 2x6 above grade, just a simple box form that spans the hole.

8) 8) 8)

[jimpad]

Yeah, I'm keen on having it well anchored.  We had a storm here a few weeks ago and my 80 year old tobacco barn which just sits on some blocks did fine; many pole barns got destroyed.  The tobacco barn has a lot of 16' diagonal braces whereas the pole barns around here have very little... especially at the door ends.  I think once the building starts racking the holes wallow and the posts pop out of the ground.  That racking force has to be resisted somehow hence my concern with the joint.  After thinking about it I don't think the $5 bracket is right for me.  The short post solution is probably the strongest but I really have a hard time putting wood in the ground. 

These are nice https://permacolumn.com/what-are-perma-columns

I thought I saw a post on here somewhere using a plastic pocket below ground level... anyone familiar with them?

[Don P]

I have a hard time buying that the earth is a permanent brace for the reasons you mention, mud wallows. Those big diagonals are the key, triangles are rigid. Add more sides without triangular bracing and you get a wrecktangle. The $5 bracket, the knifeplate, my hinge, the permacolumn, all of those have very little moment resistance to that tall lever arm above them. Your rack bracing fore and aft and side to side are the key.

[jimpad]

Slowly convincing myself to go with convention 2x4 stud construction.

[reedco]

          Some where I have seen strap bracing put on diagonally before the sheeting, wish I knew about it before I built my shop!

[Don P]

You'll also see threaded rod and turnbuckles forming X's across the post bays on some. The steel sheathing can also accomplish this to a level, the industry uses diaphragm and frame interaction (dafi) in the design phase of those. All of that is when the pole barn "grew up" and became the post frame buildings we see today.

[btulloh]

Slowly convincing myself to go with convention 2x4 stud construction.

That may be the right way to go.  You said this was going to be a house, right?  With interior partitions, a floor system, real windows?  It's a bit harder to make a post-frame building into a house, IMHO.

[jimpad]

Yes, I did say it's going to be a house.  The whole story is, it's going to be a combo barn/shop/house until we can build our final house on this property, then it will be a barn/shop... hence the waffling on construction type. 

[btulloh]

Well it could go either way then.  Don't give up on the post-frame structure just yet.  It may be the best choice in the long run.  Only you can figure that out. 

Don't let all the discussion about bracing scare you off.  The bracing required is not difficult to implement.  It's not like the stud framing doesn't need bracing.  It usually gets it's bracing from the sheathing.  Before sheet goods were used for sheathing, they used let-in braces at the corners.  It's all about triangles, however it's done.

You may want to look at some plans to get some recommended practices.  Check this out maybe:  http://bioengr.ag.utk.edu/extension/extpubs/planlist97.htm#Roof Framing and Truss Plans