Ideas for setting shed poles??

[1988mustang]

The snow will be here in Ontario in only a matter of days, and the pressure is on to get my sawmill shed completed.  I have decided to use old hydro poles to support the structure.  I had every intention of putting the poles 4 feet into the ground; however, mother nature has other plans for me.  I could only get 2 out of the 8 poles my desired depth.

Basically I have 2 corner posts in the ground at the back and need to get the others in VERY soon.  My problem is that for the other 6 poles I can only get down 1.5 feet at the most before I am hitting bedrock.  I'm not sure what  I should do to make sure the rest of the poles don't kick out and stay in place.

I was thinking of drilling a piece of rebar about 6 inches into the bedrock then drilling another 6 inches or so into the pole.   Set the pole on the rebar and brace the pole until the beam is in place and the rest of the building is in place.

Does any of this make sense?  I'm open to any ideas or criticism to better my ideas...  Any input would be appreciated...

[Bibbyman]

 



The posts on this addition to our sawshed are about 2' in the ground. I drilled holes in the section of posts below ground and drove in spike nails that were about 9" long.  I left them stick out about 5".  The post holes were about 18" in diamater.  I filled around the post with kwickcrete.

[1988mustang]

Thats not a bad idea at all.  Another problem I forgot to mention is that some of these poles will be sitting right on bedrock.  I basically scrapped down that section of the hayfield in front of my poured slab and discovered bedrock literally 3 or 4 inches down below topsoil.

[sgschwend]

You are  concerned about frost heave with the shallow holes.  Can there be heave from bedrock?  I don't know but wouldn't thinks so.

[PineNut]

I usually nail a collar of 2 x 4 around the base of each pole. After backfill, this helps hold them in the ground.

[1988mustang]

sgschwend:

I do not think that I'd be worried about the frost heave with them sitting on bedrock.  I probably should have stated earlier that my main concern was the poles kicking out from underneath the building.  To be honest my biggest fear is that my father will hit one of the front poles with the bucket of the tractor and the building will collapse.  It is kinda of a funny concern  but it does have real cause for concern.  He is only 61 years old but seems to be getting the early onset of Alzheimers...  He loves to help out but.... I could actually seem him dinging a pole with the bucket .... I'm definitely going to have a log deck to prevent the possiblity of him getting too close to building with the tractor. 

But hell he is my father and I want to enjoy whatever time I have left with him.  Plus its always a bonus having help at the sawmill   I just want to make this building secure as can be.

[Carpenter]

Attatching another piece of pole to the bottom of the pole to make an upside down T ( called a deadman) will increase the surface area of the pole and make it less likely to kick out.  It also makes it harder to pull out.  We put them at the bottom of corner fence posts all the time in the sand.  Since you are on the bedrock you shouldn't have to worry about the post sinking.  
    Another more costly solution would be to pour a concrete pad and anchor the posts to the pad.  You could pour your footings right on the bedrock.  
     I think if it was me for a pole building, I would just use the deadman and consider hauling in more dirt if needed around the poles.
      Your rebar idea would also work, to prevent kick out but, unless it is mortared or epoxied to the bedrock and attatched to the pole in some way it wouldn't do much  to prevent lift.  Do  you get much wind in Ontario?  Of course if the bedrock is solid enough and you could anchor the post to it say with a lead sinker and lag, (or some other concrete fastening system) with an L shaped piece of steel from the bedrock to the post, you'd never have to worry about it going anywhere.  Just cover it up with dirt for looks.
       Good luck with whatever you do.  

[Hanson]

Your rebar idea will work just fine, I have done the same thing many times to keep porch posts from kicking out on a slab where lift was not an issue. You can use bigger bar if need be also, I always used #4 (1/2") but you can get it up to 1"

[1988mustang]

Just wanted to thank everyone that replied.  Once again this forum has given me the support and ideas needed to complete my projects.  There is truly an abundance of information to be drawn from everyone here when I can't find my answers in previous posts.

Thanks.

[Bibbyman]

I never thought about frost heave being a problem with pole barn construction.  Down here it’s a cold day in ….. before the ground freezes more than a couple of inches.  Down here we worry more about the wind picking up a building.

[bandmiller2]

Mustang,first put sawdust or hay where the posts will go that will put the frost on hold for a wile. Clean down to bedrock and drill several holes with a hammer drill,rebar, set poles plumb and build a form around the pole and pour concrete.Be sure to cross brace the structure well. Frank C.

[paul case]

i was wondering how you northerners get by with concreting posts in. here in ne oklahoma it only freezes 6 to12'' deep every 3 to 5 years and we still have trouble with posts set in concrete getting moisture down between the post and concrete and freezing  and busting the concrete. i relize the poles in a shed wont get as much water down them but still this is a problem here where it dont freeze every year, so what about where it does?  pc

[Coon]

In Saskatchewan we can get grost up to 8 feet deep into the ground.  Most years it is four to six feet.  Normally around these parts we simply dig our post holes anywhere up to four feet deep but the deeper you can go the better.  In the bottom of the hole we put a bit of concrete and then set the post and fill with concrete to ground level.     
  Personally I would set my posts in sonotubes filled with concrete that sit up to 2 feet above ground level.  You set your posts closer to the outside of the sonotube so that when it comes time to put you siding on that you have less of an area to make up to bring the siding closer to gound level. 

[Bibbyman]

sgschwend:

 I probably should have stated earlier that my main concern was the poles kicking out from underneath the building.  To be honest my biggest fear is that my father will hit one of the front poles with the bucket of the tractor and the building will collapse.  It is kinda of a funny concern  but it does have real cause for concern. 

I was thinking,  if you have enough post material,  maybe double up on them for the first 4-6'.  This would give him something to bump into that maybe won't break or "kick out".

[flibob]

I know what you mean about your dad.  I wish mine was still tearing things up around here.  I guess I'll just have to help out my daughter more.

[Busy Beaver Lumber]

here is one other option to consider. Contact a local well driller. They usually have 8 inch and 6 inch diameter bits. You could have him drill you 8 holes for the main posts 8 inches in diameter, then have him go back with the 6 inch bit and have him drill 2 holes in front of each of the main posts and set concrete filled metal pipes in those to hole to provide protection for the main posts in case Dad get a bit wreckless with the tractor.

They usually get $8 a foot to drill and sounds like something that they could finish in about 2 hours. Might cost you a few hundred dollars, but a lot cheaper than having to rebuild the whole building if Dad knocks the supports out when trying to load a log

[sgschwend]

So you really have a soils question.  Shear strength of your soil, which will be based on how saturated it is and the soil type.

Certainly making sure the building has good shear strength can help a lot; then any shear the building goes under will be distributed around the build/foundation.

Also the larger the hole the better since the shear force is directly proportional to the area, you want the hole to take up a lot of area.

I am not that old but I too have a habit of smacking my posts.  Mainly my front gate which I have a habit of hitting with the rear end of a large truck.  A 6X6 post snaps off easily.  I am on my third, so perhaps your pop and I are related.

[r.man]

1.5 ft is a lot of strength for shear if the post will take it. If you are using hydro poles I would be more worried about the tractor. The bottom shouldn't move if hit and the top will transfer to the solid poles at the back. I would say that built that way you couldn't knock it down or pull it over if you tried with a normal farm tractor. Bad luck with the bedrock though. Around my area you always dig first because it might be close and it might not. Good luck with it and hope for a chinook.

[northwoods1]

I would never concrete a wood post in it will rot off in no time. It might be expedient but that is all. If your gonna pour concrete just set the post on the pad do not set it in the concrete. The well driller idea is crazy there is no well driller gonna come out to do a few feet of bedrock , beleive me they have a minimum charge and a good reason for it, and why would you want to? Get a well driller in to make some holes in bedrock so you can put a wood post in and backfill??? For a simple shed? Huh? 

[sdunston]

The last shed I put up I used those cardboard tubes in the ground 2 foot and left 2 foot above ground and bolted the 6x6 uprights to concrete, This way it keeps the wood off the ground and the loader forksdont do as much damange when ya hit them
Sam