Best concrete for setting locast posts ?

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I am building a split-rail fence out of locust rails and posts. The posts will be set about 8 feet apart. I plan to dig postholes about 18 inches deep, and set the posts into concrete.
What is the best method, and type of concrete ? My thinking was to use Quickcrete fast-setting concrete. With similar things in the past, I have mixed the concrete with water, and poured the mix in and around the post. But, it seems that I have heard that other folks just pour the dry power in the hole around the post, and allow the moisture in the surrounding soil to harden the mix. Others pour in dry, and then just add a modest amount of water in the hole.
What is the preferred method ??
Thanks for any advice on this !!
James
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James wrote:

Your 18" post hole seems way too shallow for a fence. Better do some more research on local conditions and methods and then worry about concrete mix. Typically, some metal fence posts are 7' tall and 3' into the ground. For a relatively short fence 2' would be a good choice. YMMV
Joe
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True enough Joe. He didn't say where he lives, or frost considerations.
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Let's please stick with the concrete question.... these posts will be 18 inches into the ground, and about 40 inches OUT of the ground. Split rails will be placed across the posts. This is a simple three rail fence, not a conventional fence with 6 foot posts.
Perhaps I led you wrong on the facts.
Thanks
James
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James wrote:

Still too short in the ground, concrete or no concrete...
In a few years they'll be laying over.
--
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James wrote:

Just plain sand works great. The only posts that should be set in concrete are the ones that need to support a gate.
--
Art

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Nope, sorry. Gonna use concrete. My question relates to the best concrete, and the method to plant them.
thanks !!
James
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The best concrete to set posts is none. A couple inches of gravel in the bottom and ALL the dirt back in the hole is the "proper" method.
And 18" is too shallow; a waste of, time, effort, money -and- concrete if you're still set on using it. 30" is minimum and probably code, and 36" is better.
Locust is the best choice for the posts, but you'd be better off setting them on fire rather than in concrete. Nothing lasts forever, try digging out a post set in concrete. By the time you're finished you'll have changed your mind, if you live through it.
The concrete mix doesn't matter, any one will rot your posts as well as another. -----
- gpsman
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I guess I will at least answer your question -
Most big home centers carry "post-set" concrete. You dig the hole, put the post in (with space around it) fill the space around the post with dry mix, add water, and mix it up by pushing a pc of rebar up and down in the "soup". Sets quickly, works fine and is very convenient.
JK
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Sorry, but I must respectfully disagree about putting dry mix in the hole. I have seen this done, but I have never seen it work well - fences were always leaning within 3 or 4 months. It is not possible to mix the concrete in the hole - there will always be dry pockets no matter how much poking and prodding is done.
Mix your concrete in a wheelbarrow and pour it into the hole.
Bob-tx
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[flup set to a.h.l.g.]
James said:

Just curious, but when the wood rots away, how will you replace it? And, you've been told (more than once) that the depth you've chosen isn't deep enough, yet you insist on not heeding advice. You seem to have the answers, so which one would you prefer to be told about the concrete?
--

Eggs

.sig not found. (A)bort, (R)etry, (F)ail?
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James wrote:

There is no "best". The kind of concrete is irrelevant. As long as it is mixed properly any concrete will do what you want.
--
Art

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If OP INSITS on concreting them in secure them in place, tied off with ropes or something, use dry mix its more convenient, leave set tied up a week or so flood area a couple times, so its all hardened
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I would agree. But any set in concrete should not be set completely in concrete- a couple inches of gravel in bottom, then post, then 1/3 or so of the hole with tamped gravel, then concrete. Give the water a place to go, instead of bottom of post always being wet. Locust takes awhile to rot, but anything rots eventually.
aem sends...
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TX hill country. Fractured limestone is immediately below the soil. Only a rock bar and alot of sweat, or, a diamond tipped auger can cut it. 18" is typical depth for corner and tensioning posts on typical pasture fence. Wood or steel posts.
Guess answers for this are kinda like gardening, depends on the conditions... Sandy soil, clay, swamp, gravel, or rocky in your case.
I pre-mixed, wetter than usual, the concrete prior to pouring in the hole with the post. Used rocks to stabilize the post during the pour, then fine tuned the plumb after the pour. Set the corners first. Dave
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We might make a fence with no post holes, just stakes in the ground for cables. Or use T-posts with diagonal corner bracing.
Nick
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Why wetter then usual?
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"Ook" <Ook Don't send me any freakin' spam at zootal dot com delete the Don't send me any freakin' spam> wrote in message

If you hadn't deleted the reason, which is in my previous reply, I could have pointed it out to you. You only scoped one sentence, actually 1/2, and presented a question to that. Dave
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Dave wrote:

Why "wetter than usual"?
--
Art

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Because I used rocks inside the holes to stabilize the posts before the pour. Wetter concrete assured me I had complete concrete saturation around and under those rocks. No cavitation due to too dry a mix for that situation. I used the inverted mushroom hole type. No gravel on bottom.
Stabilized bottom with suitably sized rocks, then top allowing at least 2" above that topmost rock to concrete surface. Used level for plumb both ways.
After the pour, I re-checked plumb and made minor adjustments if needed.
I did the tensioning posts similarly, except, I used a 3/4" offset stringline for alignment with corners bottom and top. Stringline used for rough, removed, then installed again after pour for final alignment. Of course, the 90 degree opposite direction plumb was with a level.
A few neighbors in the area said to go with 5000 psi bagged concrete instead of the 3000 psi version. They said they had no cracking problems with it over time. Makes sense as sometimes 2 feet or more of the limestone rocks will displace when using a rock pick or auger at the surface. Leaving bigger area (hole) at surface to pour. Can't be helped. So, I used that instead. Dave
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