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

 

[heehaw]

gvw, what did you plant in that corner?? i've been thinking about planting some autumn or russian olive to do the same thing..have you ever had to remove a post that was set with the dry concrete??? just wonder if it would be as hard to do as just using concrete?? removing that post stub and concrete was a real pain..i know i could have left it, but it would have bugged me forever..
heehaw

 

[dmccarty]

GVW,

Thanks for the great info.

The gates I'm looking at are made of lightwieght pipe. One is painted red and the other is bare galvanized. I can't tell which looks better. I can easily lift them so they are light. I dont' have access to a portable welder. And since I can't seem to find pipe I have been leaning towards the PT wood. I can work the wood but not the metal.

I did not think of the extra cross bracing and did not think it would be needed on these light gates. I was thinking of getting 8-10 foot posts and burying them at least 3-5 feet in the ground. BUT, I like your idea even though I will have to dig two more holes. From my pacing the road, the roadbed is about 30 feet wide, 18 feet in road with 6 feet of swale on each side. So I need some way to block off the extra six feet. I had some ideas but it sure will look better if I put in two PT posts with a cross beam to add strength to the gate posts. The farm store was selling some fence panels that I can cut to fit between the post and gate post. I think it will really look good.

I would really like to use metal posts just to provide a bit more security but our friends will have their house finished in a couple more months so the property will have at least some protection. Hopefully this fence and gate will be enough to keep the walking and driving trespassers out.

I figured I would put a rock or block to rest the ends of the gate when I left it opened. I had not thought of a rest when the gates where closed. I've been debating the length of the gate posts. I'm kinda leaning towards getting at least 10 feet of post so if I do have a sagging problem with the gates I could put a cable from the gate to the post. But I really can't see these light wieght gates having a problem. But then again an extra couple of feet in the post is real cheap compared with having to rip it all down and put in new posts to correct gate sag....

Good Ideas.

Hopefully in the next couple of weeks this will get done.

Thanks Again....
Dan McCarty

 

[dmccarty]

Bird,

The post holes might be on the big side! The backhoe has an 18 iinch bucket. If I get say an 8 inch post I'll have five inches of hole on each side of the post. That is the easy part. I THINK I can minimize digging on the back side of the hole if you now what I mean. One of the techniques I use when getting the big stumps out with the backhoe is to dig under the stump. I'll dig around the stump to open up the earth and then I get the bucket down in the hose as close to the stump as possible and start digging out. I'm thinking I'll be able to do something similar with the gates post holes. I'll end up with a hole 18 -20 inches wide and maybe 24-40 inches long. That is a bit big I suppose but the back hoe is the tool I have to use. I sure I'll be using a shovel to clean things up a bit. I'm SURE I'm going to hit some decent size rocks in the road bed which the back hoe will have to take out.

I'll let you know what happens. If work work allows I'll be doing this in the next couple of weeks....

Thanks...
Dan

 

[RobS]

Hi Dan, I put in a gate similar to what you mentioned last fall. It's a pretty light gage, galvanized steel tube 14 feet wide. The guy at Quality Farm recommended an extra long pole with a cable to support the free end of the gate or a guy wire from the post angled back to the ground. I didn't really like either of those options so I just set posts in (with concrete, not sure I'd do that again based on this thread) at the hinge and latch ends of the gate. I used 8' X 6" PT fence posts buried 4'. The one thing I did differently was to use a latch that supports the free end of the gate. When my gate is closed there is no bending moment on the hinge post, only vertical loads on both posts and that's not much since the gate is light. I put a rock in the open position to support the free end when it's open and I intend to replace that with a short post this spring. So now, the only substantial loading on the post is when I actually open and close the gate. Although I try to be diligent, I've tested it and it seems plenty sturdy to support the gate during opening and closing. I've instructed my six year old not to ride on the gate when I open it though /w3tcompact/icons/smile.gif

For a wider opening you may two gates, one on each side meeting in the middle. Obviously, you don't want a post in the middle of your lane. I've seen wheels that attach to the gate to support the weight and that may be a good option in this case. You probably only need one wheel as long as the non-wheeled gate is supported by the wheeled one in the closed postion.

Hope this helps /w3tcompact/icons/smile.gif

 

[gerard]

ditto what robs said. I have horse pasture with 10ft tube gates. I sistered another post to the free end post and when closed the fence rests on this. We never leave the gate opened so I don't need to support it in the open position. There's a lot of leverage involved when opened and over time I think most posts would slowly allow sag unless braced in the opposite direction with a ground anchor or something similar. If you support the free end except for when actually opening it, the post setting becomes less important. (BTW we just dumped the dry mix in the hole and backfilled, then tamped and added a little water on top but we only used concrete on the corner posts, not the line posts.)

 

[Billc]

Here's another idea for gate support posts. Best of all no concrete is needed. Plant two Sweetgum trees, let them grow for 25 years, and guess what, you've got great gate posts...no digging, no cement, no welding /w3tcompact/icons/smile.gif

Couple of ideas on this subject that goes back to a similar post about 2 months ago.

1. I connected a wire with one end in the tree about 5 feet above the hinges that runs to the top of the gate about 1/4 of the way from the end. The gate does not sag at all. I will always use this method from now on...if there is no tree, which is usually the case, I'll plant a long gatepost that is cross braced. I get really tired a gates that drag the ground.

2. We put up a Mule opener. It opens and closes the gate with a push of the button (like a garage door). I love this thing! When coming home push a button and it opens, push a button when you leave, it closes and locks. It works great! No more getting out and messing with the chain and lock. Can someone knock down the gate if they really wanted to? Yep. But then if they wanted to get in before all they need was a cheap set of bolt cutters. Also, I don't have power to the gate, we put up two solar pannels to charge the battery. It seems to be doing the trick.

3. The gate was unpainted galvanized tube about 14 ft., like what you can buy at any farm supply store. You can paint them any color you want. My wife said to paint it green. She meant Forrest Green, I mistakenly thought she meant John Deer Green. Opps! I know, I'm an Orange guy, but sure do like that JD green.

Like Jeff Foxworthy's joke: You may be a Red Neck if you've ever climbed a water tower with a bucket of John Deer Green paint to defend you sister's honor.

Bill Cook

 

[Billc]

heehaw,

You are putting up a fence to block the view of a blue mobile home? Hey, those New Holland dealers have to put their dealerships somewhere! /w3tcompact/icons/smile.gif

 

[dmccarty]

Here is what I did last weekend and what I'll be doing this weekend.

I went to the farm store last Saturday and did a lot of thinking and looking. I did not like the gate post material they had on hand. They had 12-15 foot long PT poles and 6x6 PT posts 8-12/15 feet long. The poles just did not looked treated enough. I could see where the chemical did not look like it had fully penetrated to the core of the wood.
I should have stopped at the local PT plant on Friday but I was to busy at work to do so.

I ended up getting 10 60 pound bags of Quickrete. The instructions said I should use 20 but I figured I could get it done with 10. I ended up getting two 6x6 and two 4x4 PT posts from Home Depot. They were slightly better than the farm store.

Sunday I burned a pile of wood I had been stacking for a couple of weeks. What fun. I hate the first hour of the burn and I sat around watching the fire for the first two hours making sure everything was fine. The wind started gusting when I had the fire going but after the first couple of hours, when the fire was down to a nice burn the wind stopped gusting.... Seems like that always happens....

Eventually I started the gate construction. I finally measured the roadbed with a tape. Roadbed meaning what ever is covered in gravel. After digging around in the grass, the road has been abandoned for 20 years or more, I was able to find the edges of the gravel. It looks like the road is 21 feet across. Look like I'm going to have to buy a 10 foot and 12 foot gates to make the span. I setup the tractor parallel with the road where the posts are going to be. I was able to dig two holes about 36-30 inches deep pretty quick with the backhoe. The holes were maybe 30 inche long. One hole is for the 6x6 which will hold the gate. The 4x4 I about six feet away from the 6x6 and will be used to support the gate posts as well as hold fencing material. The problem was the 4x4 hole. Its near a ditch that had a trickle of water from the constant rain we have been getting. As I was cleaning out the bottom of the hole with a shovel, guess what I found? A bunch of water! 8-( Grrrr... I started filling and tamping the hole to try to keep the fence out of the water but I'm not sure how successful I was. I ended up with the post maybe two feet in the ground. The 6x6 went it real easy. I put in large rocks in both holes as well as gravel to try to get some drainage. I think this is going to work on the 6x6 but the 4x4 is going to be wet.

By this time it was obvious I was not going to finish the other two posts on the opposite side of the road. I really wanted to get this done last weekend so this weekend I could hang the gates and finish the fence. But it looks like it will be another two weekends. 8-( If I had not done the burn I would have gotten most of this done.....

After I got the posts plumbed, I used three 1x.5 x36 inch stakes screwed into the post to hold everything in place, I started tamping in dirt and adding concrete. The 4x4 that was in the newly formed pond was a concern. My origional plan was for the 4x4's to get two bags of concrete while the posts got three. With that 4x4 being shallower than I wanted, I added a third and fourth bag. Since I knew I was not going to finish I added six bags to the 6x6 post! As I put in the concrete I added a bit of water from the ditch to get things going. I also added baseball to basketball sized rocks around the posts and in the concrete to add mass to the whole mess.

We have been getting rain all week so I'm sure there is not dry concrete in the holes at this point. This weekend I'll finsh the other side of the road and I supposed next week I'll finally hang the gates.

I'm going to be supprised if the posts move once everything is finished. The gate posts has 360 pounds of concrete plus another hundred pounds or so in rock. The gate post will be tied into the 4x4 support post for more rigidity. I don't think the gate weighs more the 50 pounds. If I see any sag in the gate I'll put in a cable to support the ends of the gate.

Lessons Learned:
- The backhoe will dig post holes. It does take a bit longer to tamp in the dirt in the unused part of the hole but its cheaper than getting an auger at this point. Good workout for the upper body!
- Square posts are more work than round ones. Square posts have to be made so that the faces line up in a row. Not really a concern a with round posts.
- I really did need 1200 pounds of concrete! 8-(

Hope this helps those who like to overbuild.....
Dan McCarty

 

[RJohnson]

I wished that I could of gotten to you sooner as the fire was a perfect opportunity to address the high water issue. Mother Earth News suggests that you char the outsides of the posts to a level 6 inches above the ground level. This will keep the micro-organisms that cause wood to rot to a minimum and increase the longevity of the posts.

Randy

 

[gvw]

Does the charring apply to treated or non-treated posts. I have been told - not sure where- that the fumes created by burning pressure treated or CCI posts is hazardous.