Precasting my own concrete columns for pole barn?

[IHDiesel73L]

I've seen those concrete columns that you bury and bolt your posts to for pole barns. I've been leaning that way because Googling "pole barn" and "rot" yields 1000s of threads about barns that have rotted off at ground level and are needing to be jacked up and redone. I'm wondering how difficult it would be to cast some concrete columns myself-I have a bunch of melamine left over from some concrete countertops I did a while ago. It would seem to be easy enough to build some melamine boxes, put in some rebar, pour in concrete, let it cure for 28 days, and remove the form. I would need 12 columns and could probably do 6 at one time. Each column would take one 80lb bag. After that, it would just be a matter of fabbing some steel brackets to attach the posts.

 

[kf4uda]

They make forms that can be used for that purpose.

http://m.lowes.com/product?langId=-...d=3005464&store=595&view=detail&nValue=SEARCH

 

[s219]

Why bother making forms or pre-casting? I'd just dig holes where the posts are supposed to go and pour your columns in the holes (like tall footers really). You can attach your brackets to the dry concrete via standard methods, or simply stick threaded j-hooks into the wet concrete and later bolt to them.

I think there are some tricks to avoid the posts rotting at ground level. That mainly seems to be a problem when water pools or can't drain from around the post. You can either protect the post or make sure it drains properly. Some people set posts in gravel to enhance drainage.

 

[BeezFun]

I love concrete, so I'm not trying to talk you out of columns. But I just took out some treated posts that had been in for about 10 years and they looked as good as they day I installed them. I think the problem is getting treated lumber that isn't designated for continuous ground contact. If you have decent drainage and buy the properly treated posts, you'll probably be dead before the posts rot, unless you're still in your teens.

 

[Sawdustsmb]

Our machinery shed was built on concrete "posts" coming up to about a foot above ground level in 1953. Only problem is the powderpost beetles in the hardwood poles above that!

 

[Looking4new]

If you have access to a post hole auger it would be easier on you to punch the holes down below the frost line and put sono-tubes in the holes and back fill around the tubes and pour your concrete. You don't have to worry about taking the cardboard off the tubes below grade, just above after it cures. they are called sono-tubes up here and Lowes in the 'states sells them. Lowe's Home Improvement but not as sono-tubes but they are the same thing.

 

[EddieWalker]

Each column would take one 80lb bag.

How big are these columns going to be? An 80 pound sack of concrete isn't very much concrete.

As others have said, rotting poles are from either not using pressure treated poles, which is very common in older barns, or not creating any drainage when building up the pad. They rot because of water sitting there. If they are inside the wall of a bar, and water drains down and away from the barn, they will last longer then you will be alive.

The advantage of putting a pole in the ground is the massive amount of sheer strength it gives you. Setting a pole on top of concrete eliminates all that strength and now you have to add sheething to the walls to stop them from racking. Poles in the ground is the most cost effective way to build a building. Once you start changing that, costs are going to increase for the same results.

Are you planning on a dirt or gravel floor, or will you pour concrete? If it's going to be dirt or gravel, then poles in the ground are the best choice. If you are going with a concrete pad, then stick building becomes a better option then pole building because you can put your walls on concrete, just like a house is built. More money, but a lot nicer with a concrete floor.

Eddie

 

[Bigkrank]

I am not sure about now, but some years ago Morton would not give you the same guarantee, a 5 year no questions asked wind damage 100% replacement, if you used their concrete post or a poured footer. They told me posts in the ground would withstand much more.

 

[IHDiesel73L]

How big are these columns going to be? An 80 pound sack of concrete isn't very much concrete.

I was planning on attempting to copy the Perma-Column design, so the column would be 4 1/2" x 5 1/2" x 48" - The same footprint as the laminated 2 x 6 post that would be sitting on top. The column would contain .7 cubic feet of concrete, which is slightly more than an 80lb bag (.6 cubic feet), but that doesn't account for space taken up by rebar. I have plenty of steel plate laying around to create brackets to bolt the posts to the columns. I get what others are saying about sono-tubes/just pouring concrete in a hole, but by comparison that method uses A LOT more concrete. For example, a 12" x 48" sonotube footing needs 5 and a 1/2 80lb bags x 12 footings.

As others have said, rotting poles are from either not using pressure treated poles, which is very common in older barns, or not creating any drainage when building up the pad. They rot because of water sitting there. If they are inside the wall of a bar, and water drains down and away from the barn, they will last longer then you will be alive.

I have a lot of clay in my soil and the only place I can put a barn on my property is kind of a wet area to begin with which is what is making me think twice. The land does slope a little, so I have thought about running black drain pipe buried in gravel along either side of the barn about 8" deep, parallel to the long side. They would daylight at one end of the barn and drain into a ditch running along the back property line. Would that, along with burying the poles in a mixture of pea gravel and sand keep them well drained? I just don't want to build something that's going to need a complete rebuild in 20 years, so the uncertainty of using wood in the ground scares me. I'm a fairly young guy (33)-so I want to be filling my barn with toys when I'm 53-not jacking it up and putting a foundation under it

Are you planning on a dirt or gravel floor?

Gravel/stone dust.

 

[flusher]

It depends on how tall you plan to make your columns. If you just want to raise the bottom of the posts 6 inches or so above ground level, then I'd just dig holes and pour concrete around rebar and Simpson post brackets. That's the method I used to build a 20x28 ft equipment shed a few years ago.



If you want taller columns and you can buy ready made columns, go that way. Other wise you'll have to custom build them as you indicated using forms. To clear the area for that equipment shed, I removed a few dozen tall concrete columns that used to support an old dairy barn on my property (it burned down in the 1950s).



Needed my Mahindra 5525 tractor to handle these posts. Gave them to a neighbor who used them as the foundation for a new pole barn on his place.



Good luck