Digging fence post holes - auger or "post hole digger"?

[unknown]

Previously I've just used a spade to dig-out holes for concrete spurs but I'm tempted by either an auger or a "post hole digger" ... which works best? These are available from several places; the SF ones get good reviews but look a bit expensive compared to the others ... is the extra cost justified?

Supplementary: how much postcrete am I likely to need when setting a

75x75 spur into a 600x150'ish round hole? (I know I could do some sums but in this case I think benefitting from experience is going to give a better estimate)

[Rick Hughes]

pi x r2 x depth = volume required

[Tim Lamb]

Less that displaced by the post?

[The Medway Handyman]

No experience of a auger. Post hole diggers work a treat.

Got mine from Wickes years ago.

I reckon a bag a hole max.

[Onetap]

I used a post-hole auger west of London and it was great. The soil was clay and it was like drilling holes in plasticine.

I borrowed it again and used it in Essex; utter waste of time. The soil was sandy and gravelly, the auger wouldn't drill and the holes collapsed. I found a long trenching spade to be easier.

[Phil L]

buy cement and ballast and mix your own, or if there's a lot, buy a tonne bag each of sharp sand and 10mm gravel....trying to make the hole smaller is cutting down on concrete, thereby defeating the object of making a hole at all.

[Dave W]

Should you even be thinking of concrete in the first place? My neighbour's fence has keeled over because two of the fence posts have rotted in the concrete. According to several web sources this is not uncommon, owing to water seeping down and staying there to rot the wood.

She will be having a man in to dismantle the fence enough to be able to dig out the large lumps of concrete. The man said the existing hole in the concrete was too deep to drill out the old wood. While my neighbour is saving up to afford the enormous cost, I am going to try and drill out the wood using a 460cm x 18mm auger I got off ebay.

Maybe you would be better using Metposts?

[ARW]

That will not happen to the OPs concrete spurs will it:-)?

[dennis]

You don't usually need concrete at all for fence posts. If the hole doesn't collapse when you dig it a bit of gravel compacted around it works fine. You don't see many telephone poles concreted in.

[polygonum]

Telephone poles have certain differences to fence posts:

They are very often installed using a purpose-built vehicle with auger bit which is JUST the right size to allow clearance of the pole. So they have a nice, clean hole. Not a bloody great mess with collapsing sides.

They go very much deeper than fence posts.

Any gravel used to pack out a telephone pole would amount to a very thin layer over a long length of pole.

Not to say that concrete is always necessary for fence posts - but sometimes it is.

[charles]

True, but they tend to go in far deeper and the hole is machine made. When the hole has to be dug with a spade there is a large void round the post. Gravel tends to migrate into the surrounding soil.

[ARW]

dennis know all about digging holes.

[Andrew Gabriel]

Yes, if you put the posts into concrete (or into the ground), expect them to start failing after about 5 years.

If the concrete is substantial, cut a metapost spike short, and hammer it into the old stump without removing any of it. You can get repair metaposts specifically designed for this, but they're harder to find - I've only ever done it with the standard spikes, having cut the spikes shorter.

He is, well concrete spurs, which is the best solution IMHO when starting from scratch, although my 25 year old metapost fence is still doing fine, but the metaposts were better quality 25 years ago (the make was Fensock, which no longer exists).

[dennis]

The holes are frequently hand dug with a post hole tool. If you use the auger on loose soil the hole collapses and you can't get the pole to stay up.

AIUI they dig with post hole tool until they hit clay and then use the auger. If they don't hit clay they dig it all by hand.

Its actually quite easy to dig a neat hole with a post hole tool unless you hit lots of rocks/house bricks.

[charles]

or flints

[polygonum]

Especially when the flints are the best part of a foot across.

DAMHIKT

[ss]

It depends on the unknown :-) I have just used an auger in decent soils ....for the first 16 inches then one hole had a large piece of slab, another had 2 bricks and another had a wall buried. Unless you have known issues (like flint) then its pot luck. Having said that I found the auger much quicker,neater and less work than digging.

[David.WE.Roberts]

As others have said, it depends on the ground!

I bought an augur. It was no good in gravel or sandy soil and I gave it away on Freegle.

I now use the 'two spoons tied together' tool for removing waste from the hole when it starts to get deep.

To dig the hole I start with a spade - also a trenching spade which is good for keeping the walls of the hole reasonably small.

If the ground is soft I then dig out with the post hole digger described above.

When we did the fence here with concrete posts a few years back the sandy ground was so dry it was like rock and we had to break it up with a long iron bar before digging it out.

I use PostCrete or similar, about one bag per hole (depending on how vertical the sides of the hole are I sometimes get away with two bags to three holes). There are cheaper ways but it just does the job with no hassle. You don't have to fill the hole completely - just get a lump of concrete which grips the post at the bottom and grips the ground around it.

Cheers

Dave R

[newshound]

and it was like drilling holes in plasticine.

sandy and gravelly, the auger wouldn't drill and the holes collapsed. I found a long trenching spade to be easier.

+1. Auger is normally OK except in very sandy gravelly soils.

[polygonum]

Precisely how do you use an auger through a layer of clay with many massive embedded flints? Your exception clause is woefully inadequate, I fear.