How to Dig a Post Hole
To set a post, you need a post hole. For a typical 4-by-4 post up to 8 feet
tall, make the hole 1 foot in diameter and 2 feet deep. Fences up to about
4 feet high can get by with 1-foot-deep holes. Here's how to dig one.
It's not easy work, but soaking the soil first will save you some
time and trouble. To improve water penetration, drive a length of rebar
or galvanized pipe a foot or so into the earth, wiggle it out and then
follow with the hose. Repeat this in several places, and let the earth
soak awhile before you dig.
A little technique helps speed the work. To begin, use the post-hole
digger as a chopping tool, as the animation shows. Keeping the blades
spread, lift the tool and drop it, letting the weight of the digger
do most of the work. Rotate your way around the hole. Don't bother
scooping out the earth until you have a good pile of loose soil in
the hole. Then, plunge the digger down, spread the handles and lift,
removing enough earth to expose fresh stuff to chop. As you go deeper,
also go wider. (The sides tend to cave in on their own.) Try to dig
a hole that's a bit broader at the bottom than at the top. The shape
helps anchor the post's concrete base against tipping, and the extra
weight at the bottom adds stability.
Tip from the pros: This can be a strenuous job, so
save your back. Bend at the knees and use your legs to help drive the
digger and lift out the earth. Wear work gloves to protect your hands.
Finally, if you have more than a dozen or so holes to dig, don't fight
it: Rent a power post-hole digger. They're noisy and bone-jarring when
you hit rocks, but they speed the task greatly. Use safety glasses
and hearing protection when you're running it, and enlist a friend
to help. It's not a one-person job.