Cleaning out and reusing some old concrete fence post foundations?

[ponytug]

We are repairing some old fencing along the driveway, and the old fence of 8"x8" posts turns out to be anchored into 16"x 48" foundations of concrete surrounding some now insect eaten 8x8".

Could the remains of the 8x8s be augered out with a six inch auger? I just need them mostly out, not perfectly clean.

Thoughts from the auger experts here?

Any better ideas?

All the best,

Peter

 

[Lnk]

We are repairing some old fencing along the driveway, and the old fence of 8"x8" posts turns out to be anchored into 16"x 48" foundations of concrete surrounding some now insect eaten 8x8".

Could the remains of the 8x8s be augered out with a six inch auger? I just need them mostly out, not perfectly clean.

Thoughts from the auger experts here?

Any better ideas?

All the best,

Peter

Put an accelerant and burn them out. Drill a hole down the center. As long as you don't make an inferno, the concrete should be fine. You may have to clean out after.

 

[BigDaddyEureka]

I like Ink's idea there.

IF the posts are REALLY REALLY ROTTED, then yeah the snall auger should chew them right out. Hit any hard spots though, and it will be the Mad Hatter's wild ride!

 

[PowerTracManiac]

I have had some success boring out a center hole and then adding some charcoal briquets into the hole. The charcoal kept the center burning and the wood burned itself out from the center.
Once cleaned out I suggest you look into the expanding foam method of setting the new posts. The expanding foam could be poured into the relatively clean hole (doesn't have to be perfect) and the new post set with that foam. I think that would be very strong and would keep that new post nice and tight in the hole.

 

[oosik]

I DO like the idea PowerTracManiac suggests. Plus - if the big 'ol concrete blob get hooked tight on a PTO driven auger - look out man.

 

[m5040]

Sounds like more work they just mixing cement that will conform to the new hole.

 

[ponytug]

Sounds like more work they just mixing cement that will conform to the new hole.

Fair enough, it is a bit of work.

My issue is that I have about sixty of them, and as they are so deep, and heavy, extraction would be something of a project. Are you suggesting that I move over 4' and put in a new hole with new concrete?

This project has been a head scratcher for me for quite sometime. I have never done something like it before. The bigger picture is that the 8x8"s are on one edge of the driveway and hold an offset 2x10" board to form a "guardrail" at the top of a steep slope that you wouldn't want to drive down, so I would like to have them in reasonable shape. There are buildings at the bottom, amongst other things. A solution that is stronger would be better, ditto deeper is better, as it would help anchor the uphill driveway.

My original thinking "Plan A" was that I would drive a new 8"x8" down the old hole, but I am beginning to realize that isn't likely to be easy, or routinely successful... "Plan B" is pipe, if I can locate a reasonable source for 5-6" pipe. "Plan C" is using I beams. (Galvanized?) A lot depends on pricing. If I can't get a reasonable source for the parts, I will probably just do a concrete wall. My attraction for steel over wood is the rather short life of some of the 8x8s that I used to hold up the three board fence along the driveway. In less than five years a number were already rotting out.

Advice is always welcome.

All the best,

Peter

 

[ponytug]

I DO like the idea PowerTracManiac suggests. Plus - if the big 'ol concrete blob get hooked tight on a PTO driven auger - look out man.

Yes, I have wrestled that monkey before. My sister wanted some posts in her backyard, and we rented a two person auger. We powered it up and promptly hit fractured rock, which sent us flying. The professional crew that did the front yard brought in man portable equipment that drove a 24" auger through it. It took them two or three weeks.

I would probably do it with a hydraulic auger attached to something big and heavy so the auger would hit its pressure relief before tossing anything. I thought I might start with a 2" pilot auger just to see how bad it was.

All the best,

Peter

 

[bcp]

Bruce

 

[ROUSTABOUT]

You need ground contact treated wood.

 

[ponytug]

You need ground contact treated wood.

I had, and have, ground contact treated wood. What I don't have is the double treated ground contact/salt water wood. Unobtainium around here.

We have aggressive insects, clay soil, and not much of a winter to put a damper on them.

All the best,

Peter

 

[ROUSTABOUT]

I had, and have, ground contact treated wood. What I don't have is the double treated ground contact/salt water wood. Unobtainium around here.

We have aggressive insects, clay soil, and not much of a winter to put a damper on them.

All the best,

Peter

I just drove by a place that makes it.

 

[ponytug]

View attachment 735861


Bruce

Thanks Bruce!

That is "Plan K". It would be closer to "Plan B", if it didn't add so much additional pressure to the down slope retaining walls. At least with a concrete retaining wall, it has some longitudinal strength and rigidity.

This being California, on a slope, on clay soil, I think of everything, soil, trees, roads, etc., as being in slow motion downhill, not necessarily restrainable long term. Even the county road, which I am sure was better built than my driveway, is practically graffitied with tar strips patching cracks from road slippage and movement.

All the best,

Peter

 

[ponytug]

I just drove by a place that makes it.

Yup! Last time I looked for it, the only supplier that I could find was in your neck of the woods. Many congratulations! (Well, I also found one in Canada...)

The cost for shipping damp wood that far just put the project into a "go back to the drawing board and do it again" category. If I had known how bad the insect damage would be, I wouldn't have done the fence with pressure treated 8x8s. FWIW: soaking the ends with d-limonene is supposed to make them more resistant.

All the best,

Peter

 

[ROUSTABOUT]

Yup! Last time I looked for it, the only supplier that I could find was in your neck of the woods. Many congratulations! (Well, I also found one in Canada...)

The cost for shipping damp wood that far just put the project into a "go back to the drawing board and do it again" category. If I had known how bad the insect damage would be, I wouldn't have done the fence with pressure treated 8x8s. FWIW: soaking the ends with d-limonene is supposed to make them more resistant.

All the best,

Peter

You can make your own. Get some posts and set them upright in a pan with a mix of coppertox and diesel. Nothing will eat that. Coppertox from the feed store. Get some soaking now. And when you get the holes cleaned out they'll be ready.

You may can smolder the old posts. Start a fire on top and set half a drum over it with a brick or block under one side so it can get air. Used drums ten bucks, so five bucks a hole. And a whole lot of planters when finished, and drums will be clean to use.

 

[ponytug]

Thanks, I did look into that as well. You are lucky that your feedstores stock copper tox at full strength. Our local feed stores don't stock the good stuff, and even the weak stuff is by the pint.

The goal around here is 1.5lbs/cu.ft. of copper naphthenate, usually by targeting a 24hour soak in a 11% solution of 68% copper naphthenate in diesel (1+8). Right now that's running just shy of $2,000, (15 gallons of 68% delivered) just to treat the posts, which are running another $3,000. Plus the hassle of soaking and drying 40 posts. That starts to make steel look attractive...

All the best,

Peter

 

[ponytug]

So,... I have been digging around trying to find examples of people safely burning out fence post stumps from concrete anchors, and I am coming up empty. Can anyone who has done this post some detailed instructions?

@ROUSTABOUT How long does it take to smolder a post? (I have quite a few of these to do and I have some concerns about setting the county on fire, open flames, embers, all that. Over the last decade, two neighbors had burns get away from them, one firefighting bill was a $58,000, the other was over $1Million...) We are technically a no burn area, so I would need to have a detailed plan for the fire marshall.

I found a guy who bores lag bolts into the stump and pried the post out, but it was in wet clay, so I'm not impressed (that's easy, I have clay. BTDT), and not out of a concrete footer. I may still give it a go, as rot tends to be at ground level. I can get close to a ton of lift on the tractor FEL.

Stay tuned...this project is a must do, at some point soon.

All the best,

Peter

 

[ROUSTABOUT]

So,... I have been digging around trying to find examples of people safely burning out fence post stumps from concrete anchors,

You need the barrel to make it smolder. No burn, instead of propping barrel up, cut a slot in barrel and screw window screen over it. The screen will keep hot things in and let air in. Make one and try that baby out. I'd even be soaking the others with diesel so they will be ready to smolder down. Around here stumps are soldered out. But you could cut a hole in bottom of drum too to speed things up, 4x4 or so. Screw screen over hole. Your posts are dry and should go fast. You can twist 5he drum so it cuts into ground and no embers get out. Try one and see if it gets done over a weekend.

 

[MossRoad]

Have you tried throwing more insects into the hole and letting them finish the job?





Sorry. Couldn't resist.

Sixty of them is quit a bit. Can you tell how much of the post is in the concrete? Does the post go through the concrete to dirt, or is it sitting on concrete as well as surrounded by concrete?

As discussed, an auger down the middle of the wood might bite into something and OUCH!

Do you have access to long wood boring bits and a large drill to do some tests? Once you do one, you'll know if it's feasible or not.

As others have mentioned, how hard would it be to shift over a few feet and just put in new posts and bury the old?

 

[PowerTracManiac]

Just a suggestion on the poles for the ground contact. The pole barn building companies have built up laminated posts that I think are the real deal on the ground contact preservative.. You might find some through them?