My auger hit a rock shelf near Austin and I spent 3 hours digging a 4-foot post hole with a shovel

Trying to set posts for a deer fence on a limestone ridge and the auger just bounced off so I had to hand-dig through that hard clay and rock with a digging bar, has anyone else had to resort to a rock pick or sandbags to get through a job like that?

3 comments

3 Comments

wesley6397d ago

Craig brings up a good point about the sandbags but I wonder how that holds up in a serious wind storm. We get some nasty gusts rolling off the Edwards Plateau and I can just picture a couple hundred pounds of sand sliding off the rock after a few hard days. Are you guys tying the bags together or stacking them in a specific pattern to keep them from shifting around on bare limestone?

laura_wilson7d ago

Man, I read somewhere that a lot of Texas limestone is just a few inches of dirt over solid rock, so you're basically trying to dig through a sidewalk. Hand digging that with a bar is brutal, I've done it for a fence and it felt like I was breaking up concrete with a chisel. Sandbags might help if you're setting the post without a deep hole, but honestly for a deer fence you probably need to rent a jackhammer or switch to a rock-clamp post anchor.

craig.parker7d ago

Full devil's advocate here. Sandbags work fine if you know what you're doing. People act like a fence post needs to be buried three feet deep in concrete or the deer will just laugh and push it over. Set the post on the rock, stack sandbags around it, and the weight holds it steady. Deer aren't going to bulldoze a post that's sitting on solid limestone with a couple hundred pounds of sand on top. The real issue is people trying to dig a hole where there's no dirt to dig. Stop fighting the rock and work with it. A post anchor clamped to the limestone works even better than a hole in soft dirt anyway. Less rot, no concrete to crack, and you can move the fence later if you need to.