[quote=Blogstar]
I never had to do anything too complicated, one , or later on, two standard ground rods with wire sized to the service , it was legal to bend a piece of rebar up through the foundation and into the wall cavity with an inspection hole. Also a shallow trench with bare copper wire I think 20 feet of wire buried only 18 or 24 inches nothing crazy. Nobody I know did it that last way though. Good with rock below I guess.[/quote]
The amount of rod sunk or buried wire also depended upon service size. I heard of the shallow trench, but at 20 feet, it may be the old 60amp service or smaller. I think complication comes in with odd soils (dry, non-conductive). I think the other reason why shallow 20foot trench is avoided, is that it can create a differential voltage at the soil surface. I have also heard of a long rock drill being used to go into rock, cementing the rod into the rock. I think there were also restrictions on the type of rock (quartz is a good insulator).
