PostHole Auger

[Beltzington]

Going to build a pole barn and need to drill 20+ six-foot deep 12" diameter holes in extremely hard clay soil. I have done allot of reading and I am not sure the standard 3-point posthole auger is up to the task.

The Belltec looks like a good product but I am not comfortable spending $3K on a product I have never seen in use.

Rentals seem to be fence post related and I cannot find anyone who specializes in digging holes this size and depth in my area. Thought about calling a well digger but would not know what would be a reasonable charge for this service. Anything else I am missing? TIA

 

[MtnViewRanch]

Most 3pt PHDs typically are set up to drill 42"-48" deep holes. There are extensions that you can put on to get down another 12"-14". Pretty hard to get down 6' though. These type of hole drillers were not intended to drill 6' deep holes. While I'm sure that it could be done, it would be a very difficult job, and not worth the investment for only 20 holes. The hardness of your ground is not really a factor, there are down pressure kits that will handle just about all types of soil, I don't think that the Beltic is your answer either, I don't think that it is set up to dig deep holes either. Unfortunately, you are probably going to be better off hiring this type of job out to the guy that is set up to do it. I have no idea about those costs, may vary quite a bit depending on circumstances.

Just my opinion, good luck.

 

[dex3361]

The post hole augers used by the electrical utilities would work. they dig that deep. If you could locate a utility contrctor with this type of truck mounted auger that may be your cheapest workable way of accomplishing the task.

 

[Mousefield]

Depending on your situation you could get an excavator in to dig the holes. If you want just a straight hole down six feet that the previous post regarding the utility company to do it is a good idea. We have private contractors in our area that sub out to the hydro company. They are always looking for some extra income. Doing as many as 20+ hiring someone may prove to be the cheapest and fastest.

 

[whistlepig]

My Bush Hog 2102 has an extension for the augers as an option. Have to be careful that you have enough travel on the three point to lift the auger high enough with an extension.

 

[MarkV]

I am curious where you are at. I know many places require 16"holes, at least at the base, never heard of any that required 6' deep holes. Is that what your local building department asks for?

MarkV

 

[MtnViewRanch]

My Bush Hog 2102 has an extension for the augers as an option. Have to be careful that you have enough travel on the three point to lift the auger high enough with an extension.

Even with your extension, how deep can you dig? My augers go 4' and I have a 14" extension. so that would be 62", he needs 72" I can't pull more than that out of the hole without going to extenuating procedures. What is your proposal?

 

[Tul01]

Where we are about 1 1/2 hours north of North Dakota, the frost line is typically 6'. I think the majority of post frame buildings(and even lots of deck supports) are by code minimum 8' or more depending what you are doing. I think the concrete under my front porch is a 10' bell bottom hole with cement and rebar by code when they built my house. It was definitely easier/cheaper to get someone in and they put them in +/- 1-2 inches any diameter, I think they were very accurate.

Brent

 

[whistlepig]

In our area Bobcats can be rented with a PHD attached to the loader arms. Extensions for the augers can also be rented.

 

[MtnViewRanch]

In our area Bobcats can be rented with a PHD attached to the loader arms. Extensions for the augers can also be rented.

OK, sounds good, I thought that we were talking 3PT augers. A Bobcat would be the way to go, should be able to go 6' with little problem.

 

[Tul01]

I forget to add that our "guy" used a skid steer, I believe that was close to max though. Next up option was a truck mounted unit and I think that was $100.00 per hole.

 

[whistlepig]

Even with your extension, how deep can you dig? My augers go 4' and I have a 14" extension. so that would be 62", he needs 72" I can't pull more than that out of the hole without going to extenuating procedures. What is your proposal?

I have never tried going 6'. I think if I did I would have to start the hole, manually disconnect the auger, attach the extension, feed it in, dig the hole, disconnect the auger again, and then lift it from each hole. That would be whole bunch of work. For a few holes on a pole barn I could get by. Not something I would want to do all day long.

 

[tessiers]

I've got a post hole digger and for the holes you are talking I would go with a backhoe. I did 15 far a friend of mine in 3 hours a few weeks ago and with a small hoe you really don't end up with too big of a hole. Also much easier to get good compaction around the pole. A 12" hole with a 9" pole doesn't leave much room for tamping, especially if your hole isn't perfectly plumb.

 

[whistlepig]

I've got a post hole digger and for the holes you are talking I would go with a backhoe. I did 15 far a friend of mine in 3 hours a few weeks ago and with a small hoe you really don't end up with too big of a hole. Also much easier to get good compaction around the pole. A 12" hole with a 9" pole doesn't leave much room for tamping, especially if your hole isn't perfectly plumb.

This is a good option also. I have seen holes dug like this by those that were good with a backhoe.

 

[Beltzington]

thanks to all for your advice. short story, I do not yet know what the local depth requiremnet is. I was basing the 6' depth on what several individuals on the internet have said to use. my barn would need posts to extend 16' above grade and 6' is 1/3 of that (close). The frost-line in my area is 0 so I am more concerned with how the barn would hold up to loads. Based on many comments on this site 4' seems to be the reasonable depth which significantly improves available solutions. problem with submitting plans for a building permit they expect you to know what you are doing and I am working to that end. given a 4' hole the next hurdle is backfill, crushed rock or concrete. Since I plan on an enclosed living area 10' off the ground I'm trying to insure a stable platform which I am sure would meet local code. This picture might help you understand my goal.

 

[CurlyDave]

I don't know about costs, but you might want to check these guys out Pole Barn | Pole Barn Kits | Socket Systems | Home . They claim to have everything figured out and can send you a stamped set of plans for your building department.

I have no connection to them, but am thinking about one of their designs for a barn/inlaw residence.

 

[buckeyefarmer]

I used rented skid steep with hydraulic auger, worked great in rocky soil. I went 4', they might have an extension available to go deeper. I had to use 20" round footers.

 

[sodamo]

I have never tried going 6'. I think if I did I would have to start the hole, manually disconnect the auger, attach the extension, feed it in, dig the hole, disconnect the auger again, and then lift it from each hole. That would be whole bunch of work. For a few holes on a pole barn I could get by. Not something I would want to do all day long.

I did 9 holes 64" deep that way with my PHD w/12" auger. PITA, especially cleaning them out.

 

[wedge40]

how about a 6' trench? Or 7' for that matter. Then build boxes to drop into the hole where the post should be. Place poles, fill with cement and then backfill the trench?

You can rent a excavator for $1000/week. Still cheaper then $2500.

Wedge

 

[weldingisfun]

Lots of good suggestions. Let us know how it all works out.