ᐅ Earth auger for pier foundations – what diameter is recommended?

Created on: 8 Mar 2018 15:09
C
Changeling
We want to create pier foundations for a log fence, a chain-link fence, and a greenhouse. However, I don’t want to dig all of them out by hand with a spade, and renting a motor-driven earth auger is too expensive. Therefore, I’m considering using a manual auger. What size would be sufficient here? Is a 20cm (8 inches) diameter enough? There is a version from Fiskars that I’m somewhat interested in. Otherwise, I also have 25cm (10 inches) and 30cm (12 inches) augers from other manufacturers in my shopping cart. What do you recommend?

Also, should I insert PVC pipes into the holes, or is it better to pour the concrete directly into the soil?
S
Steven
9 Mar 2018 11:26
Changeling schrieb:

Why are you on the auger page?

Hello Changeling,

Using a hole auger always sounds simple, but it’s not. I find it easier to use a regular spade or a clam-shell spade. You can’t just twist the earth auger in and have the hole ready. Roots, stones, and so on get in the way. For me, the spade works better. I only use the auger when I need to set stakes.

Steven
M
meister keks
9 Mar 2018 12:02
I recommend using a motorized earth auger.
I fenced my property, about 100 m (330 feet), and dug all the holes for the fence posts by hand.
That took quite a bit of time.
I used PVC pipes for the fence posts.
Only at the corners would I skip the PVC pipes—you can just dig one hole there and pour in concrete properly.
My corners didn’t turn out perfect because of the PVC pipes.
B
Bieber0815
9 Mar 2018 21:48
About 60 individual footing pads were installed here (for fences, a swing, pergola, garden shed). I had considered using various augers but ended up just digging with a spade. It was much easier than I expected. So, go ahead and give it a try... Just do it.

I use a standard Fiskars spade and a so-called narrow digging spade (long, narrow blade). Both work great.

I also saved myself from using that digging tool with two opposing jaws for lifting soil (what is it called again?). For deeper digging, just scoop it out by hand.
K
Knallkörper
10 Mar 2018 12:10
I used a spade for my wood storage as well. I secured the holes with PVC pipes typically used for drainage. Then I poured concrete into the pipes and compacted it somewhat, after which I pulled the pipes out again. I’m not sure if this is the correct method, but my impression was that the stability should be higher if the concrete can "interlock" with the surrounding soil.
N
Nordlys
10 Mar 2018 12:46
We have two shovels: the classic garden spade and the trench shovel for digging holes and similar tasks. Get the latter, it’s great for that kind of work. Karsten
D
Domski
11 Mar 2018 16:55
@Nordlys In your flat area with moor and sand, that is sufficient. For example, we have from 30cm (12 inches) clay and loose sandstone. That's where a spade quickly reaches its limit.

I add my vote for the petrol-powered earth auger.