Building a fence - Backhoe or Auger?

[analog]

I have a BX25D with a 12" backhoe bucket. I'm about to put in roughly 400' of 6' or 8' wood fencing and want to set 4x4 posts in concrete, will probably do 50 holes or so. Given that I'd have to buy an auger (even if I can sell it at the end), or just use the backhoe, what do you guys recommend - spend the money on the auger or just use the backhoe? If you recommend the auger, any brand recommendations and size - 6", 8" or 9"? Thanks in advance.

 

[Ed of all trades]

If you use the hoe you will use a lot of crete or have to build or buy a form each post. I would watch search tempest or ebay and find a good used post hole digger. That way you have something to sell in the end.

 

[BukitCase]

+1 - the difference in concrete used would probably pay for at least half of a used auger...

Also, you probably already know this but if not, you'll want to drop a shovel full or two of gravel into the hole, THEN set the post in and brace it, THEN add concrete - and the concrete tops should be troweled down and away from the post for drainage.

The gravel lets the hole drain instead of holding the post in its own "concrete cup" full of water - sloped concrete at the surface minimizes water running down the post alongside the concrete.

Any other way (that I'm aware of) and you'll be doing it over in a few years due to rotting posts.

I'd go with the 9" auger, if your posts are true 4x4's they are 5.65" diagonally leaving half of 3.35" on each side if they're perfectly centered. 3.5" square posts (sold as 4x4's) are 5" across the diagonal, so an 8" auger would work.

HTH... Steve

 

[zionview]

Our local rental has an auger for rent. Don't know the rate, but it would be cheaper than purchasing. I've set them both ways, and I'll stick with the auger.

 

[pat32rf]

You could use Sono Tubes and your hoe but i'd prefer an auger if there aren't too many rocks. Around here I seldom can get a hole deep enough with an auger so just use the hoe, making sure I dig at right angles to the force on the post.

 

[pmsmechanic]

So why even bother with concrete? Just pour the hole around the post full of crushed rock like the power company's do. You have a self tightening post that won't rot.

 

[analog]

PMSMechanic, That's an interesting idea. If I went that route, hoe or auger, meaning how much rock do they use around the post?


Others, thanks for all the other suggestions!

BTW, I was thinking an auger on the 3 point, not a handheld one. I already tried a handheld and it was a b*tch.

 

[gwstang]

"BTW, I was thinking an auger on the 3 point, not a handheld one. I already tried a handheld and it was a b*tch. ""


Every time I see one of those hand held units, I can't help but imagine the three stooges using one of those those and what a calamity it would turn into if my two boys and I were to try it!

Makes me glad I have a three point mount PHD. The 8" works good for the 4x4 post btw. I also have a 6" auger that I have used but it's hard to have a little leeway to make the hold straight for the post.

 

[whis]

as for how much rock it depends on auger size but 5 gallon bucket full per hole would be close

 

[pmsmechanic]

as for how much rock it depends on auger size but 5 gallon bucket full per hole would be close

I would agree on that. A guy could do the math on it too I suppose. It'll also depend on the size of the post.

 

[Morning Wood]

Auger definitely. I'd just pack good stainable fill back in around it and forget the concrete. You can hand tighten posts with a bar and they will be very solid

 

[beckmurph]

I have the same problem as the OP, but I thought about going a different route.
I looked into renting a skidsteer with an auger. For about $300 dollars a day, you could poke a lot
of holes in an 8 hour period.
Rental company would deliver skidsteer and auger at 8am and pickup at 5pm. For a small nominal fee, of course.
:2cents:

 

[PRF]

Auger definitely. I'd just pack good stainable fill back in around it and forget the concrete. You can hand tighten posts with a bar and they will be very solid

Please forgive my ignorance, but can you explain how to tighten the posts with a bar please?

 

[BukitCase]

BTW, using 3/5 in. square in a 9 inch hole, 30" deep would take about 6.67 gallons of fill.

 

[analog]

Please forgive my ignorance, but can you explain how to tighten the posts with a bar please?

LOL, I was wondering the same thing. (and excuse my ignorance too)


And PMSMechanic, in reference to how much gravel, I was wondering in terms of how far from the post you should extend the gravel - ie if you do a 4"x4" post, it's good to use at least a 8" hole filled with gravel... I could care less how much it actually is volume wise.

 

[japody]

Please forgive my ignorance, but can you explain how to tighten the posts with a bar please?

Around here, we call it packing the post. We use a 6 foot bar with a flat end to tamp the fill in the hole. I personally use a 6 foot iron pipe I got from HD and screwed end caps on it. Fill the hole with a few inches of the fill material and tamp it down till it sounds solid. You will hear the difference. Repeat until the hole is completely filled. Amazing how solid the post will be at that point. Also great for building up your arms!

 

[tman1020]

When setting fence posts generally the proper method is to drill the hole three times the size of the post you are setting. So for a 4x4 (3.5x3.5) would use a 10.5 inch hole. Unfortunately augers come in 9&12. It's rare to find a10.
In most cases adding gravel is not recommend as it will allow the water to continually surround post in wet conditions. I would not use a back hoe if u can avoid it.

 

[bindian]

Hydraulic auger on your backhoe. All you have to do is cut your bucket curl line and add fittings and QDs. Run the auger with the bucket's curl and dump lever.
hugs, Brandi

 

[pmsmechanic]

Analog I usually try to have about an inch of space or more around a pole. It's sometimes hard to get all the holes in a perfectly straight line so then the poles end up being off set to one side a little in the hole to keep everything looking straight. Personally I would probably use about a 9" auger on 4x4 posts. That gives enough room to move the post around in the hole to keep a straight fence. What I usually do is set my corner posts and then run a string line between to help keep things straight. For drilling I usually just mark where I want to dig the hole but for setting posts I space the string 1.5" off to the side and then measure to set the posts. That way if one post is a bit out it won't push on the string making all the rest of the posts a bit out. If you use crushed rock you don't have to pack the posts at all. Just wiggle them once the holes are full of rock and you can feel them tighten up. If you don't like where you've set your post they are easy to change. Just lift it out and clean out the hole and reset your post.

I don't like using concrete around post because quite frankly it's a lot of work. If you make a mistake it's even more work. I'm not so sure that concrete keeps water away from the post. Every time it rains the water runs down the post and in between the cement and the post. Any cemented posts I've seen rot off in the first four inches of cement. I'm just putting posts in the way the power company's do. I really like the self tightening action of crushed rock.

 

[Apsterbobed]

"BTW, I was thinking an auger on the 3 point, not a handheld one. I already tried a handheld and it was a b*tch. ""

Every time I see one of those hand held units, I can't help but imagine the three stooges using one of those those and what a calamity it would turn into if my two boys and I were to try it!

When I was in high school we built a fence with a hand held auger. Me and my uncle had the job of digging holes, I don't know how many holes we had done but it was getting to the end of the day and we were getting tired when we hit our first rock that was big enough to stop the bit. In a flash both of us were on our but on the opposite side of the hole that we had started on, the auger was just sitting in the hole slowly spinning the motor at an idle...