Remove Fence Post in Concrete

[Eric_Phillips]

I have an 8" round fence post that rotted off. It sits butted up against a vinyl fence post. Both of these posts are set in the same concrete. There is probably 1'-2' of concrete at the bottom of the hole. Any ideas how to get the wood post out so I can replace it?

 

[grsthegreat]

nope, not if its sharing hole with vinyl fence.


however, i have successfully pulled vinyl fences out of concrete in the past. they have pulled easily for me as they dont tend to stick to the concrete. if you can pull the vinyl fence post, than you can yank the entire concrete out of the ground with a tractor bucket.

on the ones ive done (wood posts in concrete) i can usually dig around concrete and wrap a chain under the lip they usually remains towards the top. than pull up with tractor. i only try this after snow melts off and ground is thoroughly damp.

 

[not2old]

My business replaced hundreds if not thousands of rotted fence posts over thirty-five years. Only once , did we remove a post from concrete without digging out the whole thing. The post was set in a very expensive stamped concrete patio at a very high end condo. After cutting it off at ground level, we drilled as many holes down into it as we could and then made some three foot long crude chisels to remove the remaining wood. It took the whole day to remove it at a cost of about $400.00 about thirty years ago, but the customer was overjoyed as it would have cost even more to try to patch the concrete pattern and colour, which would have been a visible repair.

 

[oldnslo]

Out is only half the problem how are you going to a replacement post back in the hole unless you go with smaller diameter and can you get concrete back in the hole to keep the post rigid?

 

[ponytug]

@Eric_Phillips I am not quite sure what you mean by a wood and a vinyl post in the same concrete. Two holes, one blob of concrete, or one hole with two posts in it. Or something else? Do you have a photo?

I've been pulling out and replacing old posts in the old concrete for a while now in an ongoing roadside project. I don't know how universal my method is, but FWIW here is what I have been doing.

Tip #1 age the new posts until they are really dry. (Preshrunk)

One method I use is close to @not2old's. I use big drills to chew up the wood and long pry bars to break it into pieces and use a shop vac to get the crud out of the hole. I try to line the drill holes up to split the post into halves or quarters (ish). Then drive a new pressure treated post down the old opening.

Method #2: when the post is either in good shape or really bad shape 12" or more down, I add water and drive a new post down on top of the old post, which gets pushed out the bottom.

I back fill any gaps with mortar and then caulk to keep water out, as I think, like @EddieWalker, that ground rot is accelerated by standing water at the post.

If you don't have access to a post driver, I get the old wood post out, and pour concrete supporting a metal wood post base, or a metal post, encased in wood for looks.

All the best,

Peter

 

[Runner]

I usually drive a railroad bar down between what's left of the post and the concrete. Then pry on it a little to get the concrete to crack, then pull out the pieces.

 

[Eric_Phillips]

I got the post changed out. I was going to try the demolition grout and noticed they call for a minimum 1.5" hole. My thought was I only need to slit the concrete at the sides of the post so I ordered a 1" drill bit. I thought I could make two holes in the direction I needed to split the concrete. As I was drilling the holes the concrete blew out on the sides a little which got me thinking the caulk is not going to slit out the sides and not split away from the post. Then I tried wedging my breaker bar in the holes to see if I could force the concrete to crack the way I needed. After some brute force I thought it looked like the concrete was moving. I got the tractor out and put a chain around the concrete and tried to pull it out with the loader. It just kept trying to pull the tractor over, should have put some ballast on the three point. It did look like I had moved the concrete. SO I applied more brute force then tried pulling with the tractor form a different angle. The chain slipped off a couple times. I gave one more try with the chain and it felt like it slipped off again so I backed the tractor up and noticed the concrete hanging from the bucket. Then I went after the remaining post. After a lot of manipulation with a chain and tractor, should have had ballast, I finally got it out. The trouble with the post was it was another foot deeper in the mud than the concrete. The water table there is about 1.5'-2' down. So the post was in about 1' of mud. I then had 2' of concrete then another 1' of dirt on top of that.

Turns out the post wasn't rotted. The fence is a high-tensile PVC fence so it is under tension. The cross brace helping transfer some of the tension to the next post had broken. The tension of the fence eventually snapped the post at the ground.

 

[QRTRHRS]

I just pulled three 4x4 posts that were in the ground 30-36" with a bag of concrete. Two slid right out of the concrete but the third would not budge.

I dug down to the concrete then put a hose on a trickle from a 50 gallon rain barrel. Next day, it came right out, concrete and all. No tractor needed. Using my T-post puller with a chain hook, I increased my lifting capability by sliding my post pounder over the post puller handle.

I have used this method on round posts, railroad ties, etc. Never broke the chain or puller but it is not a process for the faint of heart.

 

[CalG]

I have an 8" round fence post that rotted off. It sits butted up against a vinyl fence post. Both of these posts are set in the same concrete. There is probably 1'-2' of concrete at the bottom of the hole. Any ideas how to get the wood post out so I can replace it?

termites or ants will do the job.