What size earth auger bit do you use for a 4x4 fence post?

   / What size earth auger bit do you use for a 4x4 fence post? #31  
I suppose most of you guys have a tractor hitched auger but for anyone reading this from a search: I put in a property line split rail fence last year, number one son helped me with this. He's used a rental two man auger before so we went out to get one, old friend works there and said to get the self propelled wheeled machine, better for an old guy like me and not much more money. That machine is a jewel. Son was really surprised at how easy that machine bores the holes, especially in the pretty rugged area, no real lifting too. And I was thinking about hand digging? Might even be handier than the tractor hitch digger, and safer too I suspect. Highly recommended.
 
   / What size earth auger bit do you use for a 4x4 fence post? #32  
You surely do not want concrete on fence posts. It will trap moisture and either rot the post, freeze and split the concrete, or both.
Well, tell that to my 30 yo fence posts. Still solid. But i mound concrete at top to displace water
 
   / What size earth auger bit do you use for a 4x4 fence post? #33  
What do you think about using a 4" auger for the initial hole and then driving the 4x4 post with a bucket or forks ? I've been using my forks to press steel posts into virgin ground and lashing them to broken off wood posts. I can even pound them with a good amount of force by cycling the loader.
Could a wood post be driven into a pilot hole ? I hate using a 6" or 8" auger because I always need extra fill dirt or gravel, with tamping, to complete the installation.
 
   / What size earth auger bit do you use for a 4x4 fence post? #34  
In northern NY;I found if you surround with concrete;the frost will jack the post up.We just built two pole barns with6x6's in the ground.
concrete pad on the bottom,4' plastic sleeve(Home Depot) around the post 1ft.above ground level,back fill with dirt.Looks good so far.
 
   / What size earth auger bit do you use for a 4x4 fence post? #35  
In northern NY;I found if you surround with concrete;the frost will jack the post up.We just built two pole barns with6x6's in the ground.
concrete pad on the bottom,4' plastic sleeve(Home Depot) around the post 1ft.above ground level,back fill with dirt.Looks good so far.
nybirdman,

Perhaps your posts, or at least the concrete surrounding the posts were above the frost line. Northern NY in a cold winter with ground clear of snow possibly/ probably freezes to 3-4 feet. I know one year in lower NH the ground froze to 6-8 feet on open field, free of snow, and we didn't have running water till August because water line froze.
 
   / What size earth auger bit do you use for a 4x4 fence post? #36  
The problem depends on where you live. Many people do not get frost heaves. The other thing is the copper preservative used in Pressure treated lumber since 2003, certainly is better for humans but does not last like pre 2003 wood. Ive seen pressure treated wood rot in 8 years. Its unreal.
 
   / What size earth auger bit do you use for a 4x4 fence post? #37  
For the past five years local utility is using foam when setting poles. They are not having poles fall over
They also use the fill the dirt back in method here. We have a 4ft frost line and none have fallen over.

I put up a firewood/tractor shed about 2yrs ago useing telephone poles and just used the pack the dirt back in method. I have even hit a few poles with my tractor with no issues.
 
   / What size earth auger bit do you use for a 4x4 fence post? #38  
Streetcar,

Several huge differences in what the power company is probably using for urethane foam and what guys walking into the local hardware are going to be able to purchase. I spent 20+ years in advanced elastomers and there are many grades of urethane for many different applications. I could bore ( pun intended ) your with the details but finished cured urethane can range from glass like to foamy elastic stretchy sponge just by changing the polymerization components/ ratios.
Power company is also sinking that power pole a min of 10 feet and probably closer to 15-18 feet into the ground and they are probably using a very small overbore tolerance which all produces a tight fit and very little foam gets used.

The power company doesn't go nearly that deep. I was surprised at how shallow that power poles are set into the ground and how loose the fit. Not at all what I expected. Check it out with your local utility. None in our area are anywhere near ten feet.
I agree on the elastomers. There are lots of types, and the epoxy foam that the power company uses probably isn't available retail.
rScotty
 
   / What size earth auger bit do you use for a 4x4 fence post? #39  
Streetcar,

Now if one wants to purchase the commercial grade utility pole setting product from then I might consider running a trial of the foam on a few posts to monitor its performance. Sika does not appear to sell a commercial line of foams for setting utility poles.
I have used the Rainbowtech products for gate posts. No sag after years. We also use the Rainbowtech products at our Sign Shop to install Post & Panel signs and they hold very will in our Colorado high wind zone.
 
   / What size earth auger bit do you use for a 4x4 fence post? #40  
Utility poles are typically 10% of the length + 2ft. So a 40' pole would be set 6', a 60' pole would be 8' in the ground.
I believe you're correct.

That's what a lineman told me after replacing all the power poles in a 6 mile stretch after the derecho in 2020 blew them all down.

10% plus 2 feet.

The new poles along highway 17 were 80 ft. long.
 
 
 
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