Replacing fence posts

[SkunkApe]

I've got a privacy fence all around my backyard.  The 4x4 fence posts are rotting at ground level.  Five of them have broken off over the last two years or so.  I replaced three of them by digging out the concrete at the based and setting new posts in concrete.  It was a lot of work.  For two of them that were adjacent to my driveway, I just pounded new posts into the hole left  by the old posts in the existing concrete.  This was easier.

I'd like to replace all nineteen remaining old posts, but hate the thought of breaking up and digging out that much concrete.  Is it OK to cheat as I did before by pounding new posts into the existing concrete?

[Harold Tuttle]

Are the new posts gonna be wolmanized?

theres prolly a good fungi / termite population in the olde holes

[SkunkApe]

Yes, the new posts will be pressure-treated.  The old ones weren't, I think.  I haven't seen any termites.

[Azrael256]

I hate to say it, but it's a bad idea.  You're tearing up the setting pretty badly by pulling out the old posts, so the new ones won't hold properly.  They need to be dug out, and replaced completely.  That includes gravel at the bottom, and fresh concrete.

Do you have kids?  This is what they're for (according to my dad).  If not, a few friends lending you a hand will make this go much easier.

[SkunkApe]

No kids.  I'm old and decrepit, too.

[Stand_watie]

Were the old posts wolmanized? If they were and rotted anyway the concrete might actually be contributing to your problem by holding water right at ground level.

My suggestion would be to get longer posts, sink them deeper and skip the concrete, or break up the concrete and just pound it down around the posts so it will hold them without holding water.

[SkunkApe]

The problem is right at the ground level, not below it.  The wood is soft.  The weed wacker is wearing it away.  My 4x4s are about 3x3s and weed wacker level now.

[Azrael256]

Why not go back in with galvanized posts?  You'd still have to dig out the old ones, but your weed whacker won't damage them.

[SkunkApe]

The goal here is to avoid digging...

Sheesh.

[K Frame]

Big mistake setting the posts in concrete. Concrete is essentially a big sponge. It gets wet, and never dries out. The only posts I ever set in concrete are gate posts, and that's only to keep the post from sagging.

Over 20 years ago I built a large privacy fence for a neighbor. All of the posts were set into pounded gravel. The only posts that were set in concrete were the gate posts. The only posts that rotted (yes, pressure treated wood rots, eventually, especially if it's kept in contact with constant wet) and had to be replaced were the gate posts.

Take the old posts off. Dig out as much of the old post out of the concrete as you can, more is better. Fill the cavity with a good high strength concrete, and drill a post foot onto what is now essentially the pad. The foot will keep the post off the concrete and will provide a good solid base.

[SkunkApe]

Mike, can you elaborate on your advice?  I don't understand.  "Post foot"?  Thanks.

[K Frame]

Essentially, it's two brackets.

Both brackets are bolted to the concrete. The upper bracket is essentially a supporting sleeve that supports the post. The whole assembly keeps the wood post off the concrete.

I'll be damned if I can find a picture of one on the internet.

[bratch]

Skunkape:

Please inform you neighbors what you are going to be doing.  
I came home one day to find my west fence laying in my yard.  The owner of the house next to decided to replace part of the fence and neglected to inform me.  My dog was loose in my yard but luckily was unable to get out thank to my neighbors fence.  To top it off the workers left through my yard the next day and left my gate partially open.  Needless to say I was a little heated but was not in the position to do anything about it.

No attack on you just wanted to vent.

[DigMe]

Whatever you do don't leave the old concrete in there.  If you're too old to dig it out then just ask around and get the name of a handyman who'll do that kind of thing.  I had two sections of fence blow down in high winds two weeks ago.  The old posts snapped off right at the ground.  I paid this guy 80 bucks to dig out the old concrete bases (which were enormous due to the previous builder using WAY too much concrete) replace the posts and repair the fence.  I just simply did not have the time to do it and it needed to be done immediately because of my dog.  I don't know...some of you think that 80 bucks might be too much but it was worth it to me.

brad cook

[SkunkApe]

The old posts snapped off right at the ground.  ...which were enormous due to the previous builder using WAY too much concrete...

brad cook

I'm in the same boat.  As I said, I already dug out 3 of them.  The trouble is, there are 19 more to go.  A fence company quoted me $1800.  I'm looking for a handyman.

[K Frame]

Why not leave the old concrete in place? Unless it's showing signs of obvious deteoriation, such as crumbling, it will be perfectly fine if you want to go the bracket solution that I've described above. I've repoured the centers of a number of fence posts over the years, including several that were at least 50 years old.

Removing old concrete lumps is backbreaking labor, and in many cases is simply unnecessary.

As I noted, dig out as much of the old wood was possible. If you have to, get a drill and a large bit and drill out the old post.