Building a pole barn

[SDM]

Hey everyone been years since I was on this site. Hope all are well. My question is whats the best way to prevent my beams from rotting?  My plans call for 10 x 10 x 17ft pine beams. The beams will be in concrete 5ft in the ground and 12ft above. The trusses will be 2 x 10's with a metal roof. Have a company that can pressure treat all the wood, but I'm scared that won't be enough. This will be a big undertaking for me and I would hate to see it be all for not in just a few years. Sorry for the length of this question. Thanks for any and all help!                             Shawn

[mudfarmer]

The wisdom seems to be if you -really- don't want them to rot, don't put them in the ground. This comes with the caveat that you are then creating a hinge point where the post connects to the foundation column or slab.

[beenthere]

Yep, best way is to keep them dry. 

[mudfarmer]

Any members have experience with this company's products? HOME | Perma Column East

[SDM]

Mudfarmer:  I'm concerned with the strength of that system. I've seen it with decks and smaller pole barns but this will be a much larger application. I maybe wrong ( it's happened more than I'd like to admit ) but I would really like the strength of 5ft in the ground.

[Brad_bb]

So when I repaired the posts on one of my pole barns, I used post protectors.  They are a plastic sleeve that goes over the bottom of the post and is 6-12 inches above the ground.  As long as the building is not open at the post, so that rain cannot go in the top of the sleeve, they will keep the post dry.  I do not understand why they still put wood directly in the ground on polebarns today.  Posts will rot off in 18-20 years.  Sleeves are fairly low cost when building the building.  Why they don't use them I'll never know.

I bought them directly from the company back in 2009 or so.  
Postprotector.com

[Ianab]

Untreated pine in ground contact has a pretty limited life unless you live in a desert or something. Locally it would be growing mushrooms in 12 months.  :-\  With heavy duty pressure treating you can get a decent life out of it, and it gets used for pole sheds here. Or some of the more durable wood will last a while. The weak point is usually around ground level where it's exposed to both water and oxygen (and fungus). 

Mudfarmer's steel stand offs set in concrete piers are one option. You could add some extra steel strap bracing for little cost if you wanted to strengthen the design.  I can see the idea behind the plastic protectors, just the wood would have to be fairly dry before it was used. What keeps water out would also keep moisture in. But if the wood is under ~20% MC, and you can keep it that way, it won't rot. 

But either way you don't want the wood in contact with anything damp, like dirt. 

[Old Greenhorn]

.......
I bought them directly from the company back in 2009 or so.  
Postprotector.com

Brad, they don't have detailed dimensional data on their website that I could find, but I did get some on the HD site. Do you know if they make these for full sized posts? I could only find the standard building dimensional sizes, which full size wood will not fit into. They have a bottom on them, right?
 Just curious, never saw those before and will keep them in mind.

[Joe Hillmann]

We built a pole shed with our own poles around 1998.  They were pressure treated by a local company,  25 years later and they dont show signs of decay.

Water management on the site is also important.  The shed is on a raised pad and it is sloped away so water isn't standing near the shed after rains allowing it to soak in and soak the poles.

[Jim_Rogers]

If you google pole barn posts in ground and click on images you'll see lots of pictures of all kinds of different methods to putting posts in the ground.

When, soon after I got my sawmill back in 1994, I cut some timbers for a fence I wanted to erect next to the driveway so I could have a gate to secure access to my yard.

I read a book on fences. It said that, what everyone else is saying, to keep the wood dry so it doesn't rot. To do that they suggested that you set your post/pole after painting it with wood preservative paint in the hole and back fill with crushed stone. Then when surface water/rain enters the hole it filters down through the crushed stone and keeps the wood dry. This is what I did and when I left the property several years ago, my fence was still standing.

About concrete, the book said if you fill the hole with concrete and then push the post in, or put the post in and then fill the hole with concrete, you're creating a concrete cup that is going to hold water until it cracks, and that water filters out. Not good.
To use concrete, they said only do the top 6 inches of the hole. Below that crushed stone. Again, to let the water drain.

My hometown building inspector told me of a pole barn building company erecting a horse barn near my sawmill.
He suggested that I go over and see how they were doing it.
The used what is called the short pole system.
What that is is you put a piece of pressure treated pole in the ground with crushed stone around it. And make this pole at least 8" above finished grade. Then stand another pole on top of this post, and sister on some 2by pressure treated to the sides to hold the two-posts aligned vertically.
Like this:


 

Now, some years from now if the pole in the ground rots out; you jack up the barn. Or hold up the barn, dig out the rotten bottom post and put in a replacement piece. 

Some pole barn companies put the in-ground section of the pole in the center of a sono tube to limit the amount of crushed stone that they need to use. I searched for a picture of this but couldn't find one. Eventually the paper tube will rot away, but until then it should hold the compacted crushed stone you've put in the hole/tube.
When I did my fence, I compacted the crushed stone with a standard wooden handled tamping tool.

Good luck with your project.

Jim Rogers

[Brad_bb]

.......
I bought them directly from the company back in 2009 or so.  
Postprotector.com

Brad, they don't have detailed dimensional data on their website that I could find, but I did get some on the HD site. Do you know if they make these for full sized posts? I could only find the standard building dimensional sizes, which full size wood will not fit into. They have a bottom on them, right?
Just curious, never saw those before and will keep them in mind.

Most pole barns in the midwest are made with posts that are 3 laminated 2x6's.  They are laminated with ring shank pole barn nails, no glue.  That's what mine were and that's what the protectors I bought fit.  You'd have to ask them if there is any other size.  I know there are some pole barn companies with solid posts, but usually those are 5.5x5.5 or so as well.  Yes they completely encapsulate the post bottom.  You want to use there as long as rain cannot enter in the top of the post protector or have rain run down the post and into the post protector.  So in an open area like the open lean to on the end of my old shop that allowed the cows to come in, a couple posts were exposed to the elements.  I ended up repairing those posts and using protectors because I was enclosing the end with a wall with sheetmetal on the outside. Hey I found the pics.  Here is the center post before I cut the concrete and dug out the old rotted post end and repaired it, then a pic of it after with the post protector, before I finished the wall closing the end off(we didn't have cows anymore).  You don't see where I cut the interior concrete because I repaired it and epoxy painted over it with the speckles in it.  It's the same center post.  I also did this for the two posts on either side of this one.


 

[scsmith42]

If you opt to direct embed a non rot-resistant wood into the ground, about the best treatment that you can apply yourself is copper napthenate (CuNap).  I buy it in concentrated form and use a 1:3 mixed with diesel.  I'll stand the posts upright in an open-topped 55 gallon barrel with the CuNap/diesel mix in the bottom - refreshing as needed over the span of a day or so.  It will wick up into the posts.

It's best if you dry the posts as long as possible before doing this.  Companies that do pressure treating prefer for the lumber to be below 25% MC before going into their tanks.

I buy from Nisus.  They have a lot of great info on their website.

[SDM]

Wow thanks! I have a lot of info to digest. Going to really study my options. I will let y'all know which route I take. Hopefully pics will follow. 

[SDM]

Thanks! Sorry I haven't responded before now. I believe I'm going to use a couple or techniques combined together. When the project gets going I will take lots of pics. Will be a bit due to a long overdue knee surgery I am having in next month or so. Really got some great advice from you guys. 
  Thanks to all of you!