[TowerTalk] Strength of Screw-in Anchors in Rocky Soil?

[Patrick Barkey]

Does anyone have any data or insight about the holding power of screw
in anchors in rocky soil?  My experience with the big ones (that use
a power auger to install) in the clay of Indiana was very good.  But
here the soil is of much poorer quality and full of rocks and boulders.

You can still get them in, but I was wondering if I shouldn't trust them
as much?

I am talking about the anchors with a 10-12 inch helix.

  - Pat
    N9RV/7 near Missoula, MT