"David G. Nagel" wrote in message
et...
Locate a piece of rebar in the concrete and carefully chip the concrete
away until you reach the metal. Then attach a heavy gage wire to the rebar
and close the hole with concrete patch. You will now have access to the
grounding grid.

Dave WD9BDZ

One should never have any rebar exposed to the air. It will rust and expand
breaking the concrete. If put in correctly, it will be about 3 inches
inside the concrete.