Using a 24" Auger?

[two_bit_score]

I already knew the hp ratings for various augers from reading sales listings, etc..
As for $200, notice I said I'd be into $200 for a weeks rental @ $100/week plus a double RT to fetch the tool. It won't be my first PHD experience, just never used larger than what I've owned for many years.
Over engineering: Hmm. I suppose the engineering wall loads can be ignored and I've done it before but they are there for a reason, not something I dreamed up. I could do as the pioneers did and set it on rock piles. I can bet you this, the thousands of pole barn builders across the USA do what the build site and buyer allows per codes or not. I live in a zero code county other than an electrical or plumbing inspection some spots. This is off grid and on a farm so zero inspections. If one ignores the engineered wall load specs and I use my 12" auger, the number of piers quadruples from 9 to 4x9 = 36 holes with 12 auger. The larger holes save not only concrete but much labor as fewer tubes to fill. The cleaner worksite an auger provides vs. a backhoe/excavator is attractive too.
As said already, This soil is deep timber at the base of the ridge on a bench. For about 8-12" it's black forest soil then clay interspersed with sedimentary rocks/sandstone that fell down off the cliff above when dinos roamed. Some are big enough to be a problem. I suspect most holes would go OK though. it's not a spot where you'd plant trees using a 24" auger as in a tree nursery by any stretch!

What some are saying is that your auger may not give you the best results if you have much clay/rock/hard soil because of the size you want to use. I understand the DIY aspect so have you considered renting a mini-ex with a powered auger and a 24' bit? You would probably be better off in the long run and your job may be done much quicer and cleaner with less risk.

Just a suggestion as you seem to know all about what you are doing.



TBS

 

[nyone]

Two bit. I own a mini ex with an auger attachment and still would not auger the ground. Clay/rocks and that auger is not going to go where you want no matter how much you try. Dig the holes.

 

[Thunder chicken]

I just built a pole barn and used 24 bigfoots with 10 sonatube. I had a 30 or maybe it was a 36 auger but that does not give much wiggle room to place them on your line. I have never seen an auger used before and had a guy with a big cat skid steer do the drilling who had done lots before. It does not take much of a rock or being slightly off level/plumb to make the bottom of your hole waaay off your line. Don稚 drill a 24 hole for a 24 base! Mind you maybe your beam placement is not as critical as a pole for a wall.

 

[kantuckid]

My piers will have 6 x 8 oak bolted to them so needs to be fairly accurate as the log walls will lay on those oak outer beams. I've been up there working today with a FEL & a bucket dragging off the high side down a slope- all to drag out as much soil as possible and as many superficial rocks as possible, plenty there but as to how deep they continue, we'll see?
I'm going back with a heavy box scraper next and try pulling more soil down to my low side. So far the soil is dark, rich and no signs of clay as yet.
Once I'm fairly level then I'll see what machines are around to hire or rent & decide on 24" auger vs. backhoe vs. skidsteer? All my previous backhoe guys have died on me...
Great comment Thunder chicken on the lack of leeway on my bigfoot bases. I'm leaning toward a hoe.