My electrician ran a ground line from the main water line to the ground rod near the panel using a solid #4 wire and from the ground rod into the panel. We also have a line into the new foundation - 25ft.
My question is - he used #4 Solid which is only sheilded outside the house, but under the houe, it's all not sheilded - is this OK? I remember one time that a Private Home Inspector (when you sell a house) required us to replace the wire with a #4 Strand Sheilded Wire.
#4 ground conductors can be used without physical protection if it is not subject to damage. That is a judgment call but generally if it is stapled to and closely following, the wall or other surfaces and out of the way they consider it not subject to damage. #4 solid is actually tougher than stranded in my opinion. The code makes no distinction except when you are talking about pools or farms.