Author Topic: Replace Privacy Fence Post with Metal Posts  (Read 1099 times)

wkumtrider

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Replace Privacy Fence Post with Metal Posts
« on: May 23, 2018, 09:57:18 AM »
I have a privacy fence around my back yard and it uses 4x4 wooden posts cemented in the ground for support.  I have to replace 3-4 of the posts each year due to rotting.  I've seen Youtube videos of people replacing the wooden posts with chain link fence posts.  I was wondering if anyone on here has ever done this.  If so how did it turn out and was it worth the  money?   Was it very difficult?  I am just tired of the wooden posts rotting and having to replace some each year.

Thanks!

Bracken_Joy

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #1 on: May 23, 2018, 09:58:35 AM »
Posting to follow, curious of the answers you'll get. Our fences are in moderately rough shape, and I know eventually posts will start to fail.

Cassie

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #2 on: May 23, 2018, 10:17:10 AM »
We got sick of the constant maintenance so replaced the wooden fence with a 6 ft metal one.  We then installed privacy slats.  The neighbor and spouse did all the labor. It was much more expensive than wood but should last for decades with no maintenance.

lthenderson

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #3 on: May 23, 2018, 10:23:08 AM »
...4x4 wooden posts cemented in the ground for support.  I have to replace 3-4 of the posts each year due to rotting.

I'm not sure where the cementing wooden post things got started but it is the scourge of long lasting wooden post fences. Wood shrinks naturally as it dries out and ages. When there is cement around the post and underneath, it essentially forms a cup that gets filled with water and stays there accelerating the rot. If you want a wood post to last, put several inches of gravel underneath it at the bottom of the hole and then pack clay or dirt around it so that water can filter away from the post. The dirt should mound just slightly up next to the post at ground level so that water drains away from the post and doesn't pool up next to it. If you set it to a proper depth, it will support just about as much weight as a post with concrete. A treated fence post set in bare dirt will last a couple decades or more depending on soil type.

wkumtrider

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #4 on: May 23, 2018, 01:22:26 PM »
Thanks for the responses.  I will have to try lthenderson's suggestion on not putting concrete around the post.  Just hope it will be strong enough to hold the weight of the fence, especially when it rains a lot.

MrSal

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #5 on: May 23, 2018, 03:27:47 PM »
...4x4 wooden posts cemented in the ground for support.  I have to replace 3-4 of the posts each year due to rotting.

I'm not sure where the cementing wooden post things got started but it is the scourge of long lasting wooden post fences. Wood shrinks naturally as it dries out and ages. When there is cement around the post and underneath, it essentially forms a cup that gets filled with water and stays there accelerating the rot. If you want a wood post to last, put several inches of gravel underneath it at the bottom of the hole and then pack clay or dirt around it so that water can filter away from the post. The dirt should mound just slightly up next to the post at ground level so that water drains away from the post and doesn't pool up next to it. If you set it to a proper depth, it will support just about as much weight as a post with concrete. A treated fence post set in bare dirt will last a couple decades or more depending on soil type.


I did it differently. A friend of ours who is a contractor said he never had a fence of his fail ... so we took his advice. The posts are solid and they don't move at all. I thought it was odd but hey... its been 3-4 years and the posts look great..

We dug the holes 3-4 feet - in order to go below the frost line. Then we aligned all posts and then just filled the hole back with gravel and sand. I would say each hole has about 3 wheel carts or more of gravel. about 2 feet diameter hole. I doubt there is any type of moisture/water there... drainage is probably over the top on those holes!

405programmer

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #6 on: May 23, 2018, 03:47:11 PM »
I've always heard that metal posts in concrete is the best way to support a fence regardless of the material of the fence itself. I did that for my current span of fence and just put up the boring wood privacy fence style. You have to have brackets to easily attach the wood to the metal posts but it's all pretty straightforward.

As MrSal pointed out make sure you get your concrete down to the frost line otherwise over time your posts can heave and shift making your fence look wacky and fail much sooner. That means if you have a 6ft tall fence you'll likely need 8 ft posts to get down in the earth enough but still provide support close to the top. I always found the hardest part of fence making to be measuring, digging and setting the posts. Once you do that the rest is just holding the wood up and screwing everything together.

Oh and there are lots of different strength metal posts. If you attach wood to the posts you'll probably want the heaviest duty posts you can find. Otherwise the first strong wind might bend your fence right over!

lthenderson

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #7 on: May 24, 2018, 06:50:00 AM »
I've always heard that metal posts in concrete is the best way to support a fence regardless of the material of the fence itself. I did that for my current span of fence and just put up the boring wood privacy fence style. You have to have brackets to easily attach the wood to the metal posts but it's all pretty straightforward.

As MrSal pointed out make sure you get your concrete down to the frost line otherwise over time your posts can heave and shift making your fence look wacky and fail much sooner. That means if you have a 6ft tall fence you'll likely need 8 ft posts to get down in the earth enough but still provide support close to the top. I always found the hardest part of fence making to be measuring, digging and setting the posts. Once you do that the rest is just holding the wood up and screwing everything together.

Oh and there are lots of different strength metal posts. If you attach wood to the posts you'll probably want the heaviest duty posts you can find. Otherwise the first strong wind might bend your fence right over!

Just to clarify, the OP and I were talking about concrete around wooden posts. Concrete around metal posts is not as much of a problem.

wkumtrider

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #8 on: May 24, 2018, 08:31:23 AM »
Thanks everyone!  It is interesting about the gravel/sand in the post holes instead of concrete.  My posts are several feet deep to go below the frost line.  I think I will try this option on the next post I need to replace, which is soon!

TheWifeHalf

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #9 on: May 24, 2018, 09:28:57 PM »
This is just our experience, maybe we just got lucky?

We put our privacy fence up 22 years ago, pressure treated posts. It's dark and I can't go out and measure their size right now.
We used a 4 ft hole, about 14 inches diameter, with about 2 ft covered with concrete. I check the stability of the fence weekly, and if there are holes being dug, because of the dogs. Right now, the posts don't budge.

About 8 years ago this area had a tornado. The next day I looked out and there was a string that I can best describe as the kind of string TheHusbandHalf uses, with blue chalk, to mark a straight line, so a substantial string, that was 30 ft in the air. It was going across the whole yard, and was held by the trees.
Then we noticed one of the fence posts was leaning in.
It was being held up by the fence panels it was attached to. The post must have sustained some strong wind, but there was no actual tornado here. Where the post broke, there was no sign of rot, it was like when we put it in.

We have a high water table here, especially out back
Like I said, maybe we were just lucky!

bacchi

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #10 on: May 25, 2018, 03:47:58 PM »
There are galvanized metal posts in concrete in my backyard that have been there for decades. Having helped a friend replace 4x4s in concrete, it's not a chore I want to do at home. Whatta pain in the ass.

MrSal

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #11 on: May 26, 2018, 09:48:22 AM »
Thanks everyone!  It is interesting about the gravel/sand in the post holes instead of concrete.  My posts are several feet deep to go below the frost line.  I think I will try this option on the next post I need to replace, which is soon!

I thought it was weird especially going against what I had seen online but hey it works... we used 10 foot posts - because we dug 4 feet into the ground and then we have about 6 ft of fencing...

I agree that metal posts in concrete is probably the 100+ year solution ... then once the fence fails, all you need is to replace the boards and not the posts. But even on my case, I think the boards will fail way sooner than the posts, which are looking great after 3 years. Fence is solid:







« Last Edit: May 26, 2018, 09:51:14 AM by MrSal »

rosarugosa

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #12 on: May 27, 2018, 04:44:48 AM »
MrSal: That is a great looking fence!  All wood, right?  What type of wood is it?

lthenderson

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #13 on: May 27, 2018, 07:16:38 AM »
I agree that metal posts in concrete is probably the 100+ year solution

I've replaced many metal posts set in concrete over the years. See the same "creating a giant concrete cup" description up above. What happens is the water rusts out the post, mostly cheaper (read lighter gauge metal) T-posts to the point where a breeze bends them over under the load of the fence. I'm sure if you got heavier gauge metal posts that it will take longer for them to rust out but they eventually will as well. When I have set T-posts, I always apply a couple coats of fresh paint on the buried ends before sticking them in the ground. They get beat up and scratched down to the metal in the stores and I've always theorized that covering up those scratches will hold off the rust even longer.

MrSal

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #14 on: May 27, 2018, 03:09:00 PM »
I agree that metal posts in concrete is probably the 100+ year solution

I've replaced many metal posts set in concrete over the years. See the same "creating a giant concrete cup" description up above. What happens is the water rusts out the post, mostly cheaper (read lighter gauge metal) T-posts to the point where a breeze bends them over under the load of the fence. I'm sure if you got heavier gauge metal posts that it will take longer for them to rust out but they eventually will as well. When I have set T-posts, I always apply a couple coats of fresh paint on the buried ends before sticking them in the ground. They get beat up and scratched down to the metal in the stores and I've always theorized that covering up those scratches will hold off the rust even longer.

How about creating a concrete pad, and then use one of those J anchors with an elevated bracket for the metal post? This way the metal post would never see water.

rosarugosa, yes all wood. It;s just normal PT pine wood. I wanted it to be Ipe or Tigerwood, but the money for that would be outrageous (probably north of 20,000 dollars)... so Pine it was and then stain to emulate the effect of tigerwood and Ipe ...


Lulee

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #15 on: May 28, 2018, 11:41:36 AM »
MrSal's takes the prize for beauty.  It looks like he spent tens of thousands on it.

As an alternative, you could go the route the Shaker's did up, at least at their Canterbury, NH location and use granite for all/part of the posts.  They wanted something sturdy that wouldn't rot or get eaten away by insects.  The closest picture I could find that showed one variation of how they did it is here http://shakers.pastperfectonline.com/photo/FCB50E0C-9B14-489D-8D81-590058681410.  Those are some long lasting posts and I find them beautiful.

MrSal

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #16 on: May 28, 2018, 12:57:42 PM »
MrSal's takes the prize for beauty.  It looks like he spent tens of thousands on it.

As an alternative, you could go the route the Shaker's did up, at least at their Canterbury, NH location and use granite for all/part of the posts.  They wanted something sturdy that wouldn't rot or get eaten away by insects.  The closest picture I could find that showed one variation of how they did it is here http://shakers.pastperfectonline.com/photo/FCB50E0C-9B14-489D-8D81-590058681410.  Those are some long lasting posts and I find them beautiful.

I spent less than 2k on it... I believe it was about 1800 dollars all together in the end, and a few weekends of sweat intensive work :)


lthenderson

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #17 on: May 29, 2018, 09:16:55 AM »
How about creating a concrete pad, and then use one of those J anchors with an elevated bracket for the metal post? This way the metal post would never see water.

I've used that method for wooden posts in buildings with great success. I doubt it would work well in a fencing application though. The wind load on the posts combined with just a few fasteners between the post and the bracket probably wouldn't work out well.  If you had some way to brace it against the wind load then perhaps assuming all stainless brackets and hardware.

The only fence that I have ever seen that will truly last 100's or even 1000's of years is the old mortarless rock wall.

wkumtrider

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #18 on: May 31, 2018, 07:27:50 PM »
MrSal, great fence!  That is held up by gravel and sand only?  Very nice.

MrSal

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Re: Replace Privacy Fence Post with Metal Posts
« Reply #19 on: May 31, 2018, 07:37:33 PM »
MrSal, great fence!  That is held up by gravel and sand only?  Very nice.

Yup.

2 feet diameter hole about 4 feet deep, post in, and fill it about 3/4 gravel and 1/4 sand all the way to the top.