A trick for setting posts in rocky ground that actually worked for me

I had a job last fall in the hills outside Boulder, and the ground was just packed with fist-sized rocks. My usual method of digging with a clamshell and a bar was taking forever, maybe 45 minutes per hole, and I was getting wrecked. Out of pure frustration, I grabbed my demo hammer with a spade bit, the kind you use for breaking up concrete. I figured, what's the worst that could happen? I used it to basically pulverize the rocks right in the hole, turning them into gravel and dust. It was loud and messy, but I could clear a hole in about 15 minutes. I was worried the post wouldn't set right, but I packed the concrete slurry in real tight and those posts are solid as anything now. Has anyone else tried something this brute force, or is there a smarter tool I should look at for that kind of soil?

3 comments

3 Comments

joseph_murray812d ago

That demo hammer trick is basically just making your own aggregate on site. The concrete binds to the smaller crushed rock just fine, maybe even better. Sounds like a solid hack for brutal ground.

the_susan29d ago

Honestly I always thought you needed a clean hole for concrete to set right. Your story about the demo hammer making gravel and it still working perfectly is kind of blowing my mind lol. I've wasted so much time trying to chip out whole rocks in that same garbage soil. Next time I hit a rocky patch I'm totally renting one of those hammers, the time saved sounds worth the noise and mess.

kevin17929d ago

Oh man, I should clarify! The gravel from the hammer is fine, but you still gotta get the big chunks out. It's more about busting the rock into smaller pieces you can actually remove, not just turning it all to dust. Still saves a ton of time over trying to dig out a whole boulder.