I am trying to dig holes that are 18" square, and 12"+ deep.
The site is mostly undisturbed soil, although there is a thin layer of topsoil or fill in some areas. The soil is glacial till, so a mix of sizes. Plenty of rocks.
I use a mattock to loosen the ground, then a shovel to, err, shovel it out and clean up the sides. I have trouble when I get close to the 12" mark, because I can no longer swing the mattock into the hole. If I need to go deeper (because I hit soft fill dirt) then I'm kinda stuck.
It's also taking a while, and I have 30 holes to dig, so I'd like to think about ways to speed things up.
For context: I'm going to fill with gravel and set pre-cast pier blocks on top.
Any suggestions?
Best Answer
For that size hole, I'd probably go with a Post Hole Digger. If it's sharp and there aren't too many rocks or roots, you just shove it into the ground, pull the handles apart, and lift.
However, for the number you're going to be digging, it might be better to visit your local tool rental shop, and rent a gas powered auger. If you can get a second person, the two person models are a lot easier to control ... you can then square it off with a shovel, and either get the last bit out by hand, or with a post hole digger.