post set in concrete, never again

[heehaw]

well, i got another lesson this week-end about why i will never use concrete around post any more; several weeks ago, someone took out 3 corner post on my place; it was really wet at the time; the actual corner post just pushed over, and it was 3 ft deep; the 2 side/brace post broke off at ground level; i found out why yesterday; i had put concrete around the side/brace post; and it took a lot of diggin and liftin to get the concrete and remaining parts of the post out of the ground; they were @ 30 inches deep; it would have been a lot easier if they had pushed over too; anyway, i have learned my lesson; no more settin the post in concrete.
heehaw

 

[RJohnson]

HeeHaw
Sorry to hear about your troubles, but I still believe in concrete. You must have a high water table problem. The latest issue of Mother Earth News Magazine has a great article about putting wooden post in high water table ground. You might want to check it out. Good luck on replacing your posts.

Randy

 

[Anonymous Poster]

This is of interest to me in that I plan to build a 6' or 8' high fence this year so that I don't have to look at the blue mobile home across the road any more! I had considered setting the corner posts in concrete but now I am not so sure. Anyone with suggestions?

 

[RJohnson]

Here is oil country most people make their corner posts out of oil field pipe. They put in two corner posts to make an "L" shape and weld a pipe stifferner between them. They are usually set in concrete and last forever.

 

[heehaw]

no high water area here; just had a lot of rain prior to the kids running thru the fence; for a standard farm fence, barbed wire or woven wire, from now on the post will have pea gravel around the post; my dad told me years ago that pea gravel was the best way to go; the more you tap on the post the tighter it gets; for a wooden privacy fence, which will catch a lot of wind; brace post and concrete are probably necessary. my fence gets run thru @4 times a year; this was just the first time they got the corner post; they usually just take out 30 ft of fence and a bunch of steel post and then back out an keep going, or occasionally, drive thru the other side of the fence to keep from gettin caught.
heehaw

 

[Bird]

heehaw, a few years ago a neighbor told me that he had heard the pea gravel was the way to go; keeps the posts tight because the pea gravel can just keep settling around them if they get loose. So, when we built the fence around the garden, that's what we used. Bad mistake. It may be a good idea in some types of soil, but not this black clay/loam. When the ground got really dry, the soil shrank and cracked, and the gravel disappeared down the cracks leaving the posts very loose.

Bird

 

[gvw]

Having set 100's, if not more posts I provide my 2 cents worth on this subject. In days by gone and back on the farm setting a post involved a lot of heavy hand tamping of the backfill matierial with a flat nosed bar. We used only the natural soils that were the result of drilling the holes. The secret to longtiviety was that my father always had posts soaking in a 55 gal drum of creosote (sp?) which is no longer available. A very high porportion of those posts are still standing solid 45 years later - boy that just dated me!
Today we use the pre-treated CCI posts set with hand tamping and dry concrete. As I have better usage of my life than re-setting posts - I try to get it done right the first time and never worry about it again. We use one bag concrete dry mix per hole mixed with the natural soils. We alternate backfilling several inches (6-12") of dirt and dry concrete with hand tamping. We pour the concrete into the hole dry and let mother nature provide the moisture. Posts are usually let set at least a week before we "pull" wire from the corners. The test for readiness is that if we walk up to a post and shake or move it - its not ready yet. The intermittent layers of concrete and dirt provide lateral structural strength and allow moisture to escape through the layers of dirt. This system has worked reasonably well for us but we are also building what is supposed to be a "permanent" fence.
An additional thought for the fence that keeps getting mowed down from vehicular assualt -try planting anti-vehicle vegitation. We have a corner that was perodically getting removed that is now "bush protected" - works great!

 

[dmccarty]

GVW,

How did you handle gate posts? I'm getting ready to put in two 12 foot gates and I'm still trying to decide if I should use big pipe in concrete or PT timber/cedar posts. I can't decide if the wood should be in concrete or just tamped. My gut feel is put them in concrete regardless of the post material.

PT wood is easily available at the farm store and the gates are set up to be placed into a wood post. I think I would rather use metal but I'm having problems finding pipe as well as the pieces to attach the gate to the post.

I like the idea of layering the concrete with soil and letting nature provide the water. I don't have water on the property so I have to bring it in. I have a couple of 5 gallon water bags I could fill but that is the only way I have to make the concrete. I might still bring in the water to at least start the concrete. If I run out of water its nice knowing MommaNature will help out.

My problem is how to dig the holes. I don't have an auger but I do have a backhoe. I'm thinking of getting at least 6 inch posts which is overkill I think. I'm going to use the backhoe to dig the hole and try to leave as much soil undisturbed as possible. But I'm going to have lots of soil to tamp. I think I'll use a couple bags of concrete. I'm going to practice digging the hole somewhere else first......

What I'm really thinking on, is how I can attach the tamping rod to the FEL or backhoe so I can let Mr. JD do the work!

Thanks....
Dan McCarty

 

[gvw]

Dan - Gate posts can be a real bugger if not designed, constructed and set properly. One has to consider the resting weight of the gate in both the open and closed position. First I would suggest buying the "lite weight" version of your gate. Most gates come in several weights. The heavier ones are for physical contact with livestock which is very seldom needed. The lighter version looks just as heavy but is constructed of lighter gauge and diameter material.
As for support post material the strongest - both visually and physically - would be made from 6" dia pipe verticals with 4" dia horizontal with welded butt joints and filled with concrete (verticals). If you have access to a portable welder and some pipe this is the way I would go. 6" pipe (I have done some w/ 8" - and that is really formidable) 8' long - 3' in the ground and 5' showing would provide the basis of a grand entry and closure thereto of your abode.
Second choice would be treated posts 6"-10" --- the heavier the better with 6" horizontal members. This last year I built a front gate using 8" squares (8' long) at about 7'6" oc in a 60'r arc faced w/ RS 2x8 a 12" oc vert. Each side of the gate has a curved 60' radius that is very attractive. The post that the gate hangs on is also supported by an "L" brace/post to support the weight of the gate in the open position. When open the gate is stopped by a "bump" post that has a rest for the gate to set on. I also built in a rest for the gate to set on in the closed position so the gate won't sag when some idiot climbs over even though that would be a momentary thing.
As for post holes we have come to the conclusion that the only way is to rent a skid loader with a drill bit - not to exspensieve and one heck of a lot easier than the two man drill or gag! digging by hand. As for the concrete/water - unless you moved to the desert when I wasn't paying attention - there is plenty on natural moisture in the ground to do the deed - in this case less is good. Remember that two much water lowers the strength of the concrete - less is better/good. You do not need/want soup. Drill the hole - set the post - true w/ a level - shove in some dirt - tamp - shove in some dry mix (1/3 bag) - tamp -dirt - tamp- conc -tamp- dirtetc. You can buy a tamping rod at the hardware store - I actually use a 7' piece of 1-1/2" black iron pipe with nipples on both ends - heavy enough to get the job done but will not wear you out.
Go get em!
GVW

 

[Bird]

Dan, I'd sure like to see your post holes./w3tcompact/icons/wink.gif I guess where there's a will, there's a way, but I don't know how you'd dig post holes with a backhoe without needing a truckload of concrete./w3tcompact/icons/smile.gif We've set some posts using the method GVW described and it's probably about the easiest, and works well. We've also set some by mixing the concrete in the hole; i.e., instead of mixing concrete, then pouring it around the post, just set the post in the hole, dump in a bucket of water, then dump in a bag of Sakrete, and stir it a bit with a steel rod like a piece of rebar.

Bird