# Setting 4X4 posts into ground



## Daniel Holzman (Mar 10, 2009)

This is a lean-to shed, so presumably longevity is not that important to you. Unfortunately most wood tends to rot when directly buried in the ground, even when surrounded by concrete. You might get 10 - 20 years out of a direct buried post. An option is to use steel posts, they will last much longer than wood. If you want a longer lifespan and want to use wood, you would normally support the post above grade on top of the concrete footing using a galvanized steel standoff bracket. Simpson makes a whole line of them.

But back to your project. If you want to direct bury the post, you dig the hole, compact the bottom, add some gravel, install the post with a brace to keep it vertical, mix the concrete, place it in the hole, vibrate the concrete, then let the mix set up for at least 48 hours before you put load on the post. You can use Quikcrete for the project, no need for fast set concrete unless you cannot wait to load the post. There are people who pour the mix in dry, then add water. I don't like this approach, since it is easy to get dry spots in the mix that never set up, or overly wet spots that do not achieve proper strength.


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## funfool (Oct 5, 2012)

I also like to mix it out of the ground to desired consistency, then pour it in.
I always try to bring the concrete out of the ground several inches, then slope it away from the post.
Encourage water run off away from the wood.
I am afraid that it is a hope this helps fix. Any way you go, that post is going to rot out at ground level.
In my case several inches above ground. Something you can try, use some roofing tar and coat the bottom portion of the post to a couple inches above ground.
I bet it helps and have done it myself, but never documented the life span of a post with and without it.
Anything you do will be better then nothing.
Good luck and have fun with the project.


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## Ron6519 (Mar 28, 2007)

I bury posts on top of a gravel base and fill in around the post with angular gravel tamped in lifts. The gravel is surrounded by a landscape cloth to keep dirt out of the gravel.
This allows water to drain away from the wood.


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## miamicuse (Nov 13, 2011)

I just saw this product: Quikcrete Fast Setting Concrete Mix and the specs says:



 Can be used for setting posts Such as mailbox posts, fence posts, and lamp posts
 *No Mixing Required*
 Pour right out of the bag into hole and add water
 *Sets hard in 20-40 minutes*
Is it too good to be true?

http://www.homedepot.com/p/Quikrete-50-lb-Fast-Setting-Concrete-Mix-100450/100318521


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## stadry (Jun 20, 2009)

yes, it is as ALL concrete is 'setting concrete' :laughing: the fun part is when people think its different or better but it ain't :no: why not just buy some post blocks @ the same place & save yourself loads of work ?


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## concretemasonry (Oct 10, 2006)

Post blocks may not be acceptable. In many hurricane/storm -prone areas it is required that the shed would be anchored to the ground than a heavy concrete block under each post. - I ran into this doing disaster recovery after Katrina.

Dick


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## stadry (Jun 20, 2009)

agree w/dick however 3' posts in conc w/your soil conditions won't prevent it from being carried away by either shear OR uplift winds,,, you might consider earth augers,,,what's you bldg dept say ? coastal bldg code's much more strict than inland


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## miamicuse (Nov 13, 2011)

stadry said:


> yes, it is as ALL concrete is 'setting concrete' :laughing: the fun part is when people think its different or better but it ain't :no:


That's basically my question. Quikcrete makes two concrete mix products for setting posts.

This one does not need mixing. You pour the entire bag into the hole and add water.

The other requires mixing.

Same manufacturer, two different products, two different instruction videos. Same thing just marketing? Or there is some substantial differences between the two?


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## carpdad (Oct 11, 2010)

Dry pour is often used on buried fence posts and those posts are kept braced until the dry mix is presumed to be wet (by hosing or rain) and cementing process began and finished. It's a guess.
Buried posts are sitting on earth and concrete isn't holding them up. For a shed, your roof would be doing more of the work resisting the wind and such. I would just compact the dirt around the post and concrete the last 6" or so with high slope around the post for better lateral resistance and once everything is dry, caulk around the post/concrete joint.


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## Colbyt (Jan 27, 2014)

miamicuse said:


> Same manufacturer, two different products, two different instruction videos. Same thing just marketing? Or there is some substantial differences between the two?



People have been dry pouring and adding water for many more years than the high strength fast setting stuff has been on the market. The method works with either bag.

It might be that the more expensive stuff sets harder than the cheaper. If you ever have to break it out to replace the post you will appreciate the weaker mixture.

The gravel trick that Ron mentioned also works well. I am not familiar with the term angular gravel, around here we use compacted road fill, AKA dense graded aggregate.

Any of these methods will work okay for what you are doing. With the sandy soil I tend to lean more towards the mixed and poured version of plain old Quickrete.


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