What Size Auger?

   / What Size Auger? #1  

MikePA

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What size auger should be used to install the following posts? Initially, I thought a 6" auger would be good for the 4" x 6" posts since it wouldn't allow for much wriggle room. However, it wouldn't allow for tamping either.

4" x 4"

4" x 6"
 
   / What Size Auger? #2  
Hi Mike,

I used a 12" auger on my 4"x4" posts and and 6"x6" posts. In many cases, having the "extra space" was very handy in case the hole wasn't exactly in the right place.

Also, you need to remember to measure the diameter of the posts rather than the side dimensions. A 4"x4" post is actually about 3.5" x 3.5" and has a diameter of almost 5". A 4"x6" post is actually about 3.5"x5.5" and has a diameter of about 6.5". So, a 6" bit wouldn't help at all for 4"x6" posts, and would just barely work for 4"x4"s.

I think I'd use at least a 9". Again, my experience in my rock hard and rock filled clay is that the bit can wander a bit, so I really liked the extra room the 12" bit gave.

Hope this helps.

Rick
 
   / What Size Auger? #3  
I have a danuser with a 12" auger. This works great for me since I have been using telephone poles and cross ties for posts. I came up with the poles a few years ago and could buy them for 50 cents a foot delivered. And I got the cross ties for free. Minus the backache. So I could justify the purchase.
Now that that supply is dwindling I will probably purchase a 9" auger for normal sized posts. Twelve is just too much tamping. For all around digging I would go with a nine inch. If bigger is needed you could easily shave down the sides of the hole.

Patrick
 
   / What Size Auger? #4  
I've got a 9" Auger that I bought from TSC last year. I don't think you would have any problem tamping in a 4x6.
 
   / What Size Auger? #5  
i have been using a 12" worksaver auger, and it has worked well for posts, trees, shrubs, bushes, and gives you enough wiggle room to make sure everything is lined up, you may have to tamp a bit more, but i have been happy with the digger.

alex
 
   / What Size Auger? #6  
My Leinbach has a 12" auger which works better for me than 9" does. I too use old telphone poles for projects - the butt end can be 10" or more - and heavy. Placing them by hand is awkward. With a 12" auger the hole is more like 13"+. I put a 4' length of 12" PVC pipe into the hole to use as a temporary liner - so the post doesn't knock material down as it goes in. The extra size allows for some adjustment too. I pour in pea stone around the post - very little tamping

I found 9" holes to be a little small if any further shovel work was needed. (around here code calls for 4 ft depth)
 
   / What Size Auger? #7  
<font color=blue>I pour in pea stone around the post - very little tamping
</font color=blue>

Dick, the pea stone (or pea gravel as it's known around here) seemed like a great idea. A neighbor told me he'd "heard" that as it settled, it just got tighter so posts wouldn't loosen up with changes in the soil moisture. So that's what I did when we built the fence around the garden. It probably works great in some types of soil, but here . . . when this clay got really dry and started cracking, the gravel went right down the cracks and most of it disappeared, and the posts were loose./w3tcompact/icons/frown.gif Had to go back and tamp dirt around all the posts.
 
   / What Size Auger? #8  
Man, that's dry. Up here in the wet northeast our idea of dry is when the top inch is dusty.

Last spring I drilled holes in my "hardpan" where the drilled slug came out like a big cylinder of jello. Later in the summer it was back to near-concrete - needed downforce to keep the auger digging. No cracks around here.
 
   / What Size Auger? #9  
I bought my post hole digger for the expressed purpose of 4x4's. My dealer sold me a 9 inch auger for planting 4x4's.
 
 
 
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