Having witnessed a lightning strike and the results of the amazingly high current flowing in the earth I am a skeptical about relying on a concrete encased electrode for lightning protection. The high current flow generates so much heat that normal materials are vaporized. I saw an (illegally) buried 14/3 extension cord dig a 12"deep trench over forty feet in hard packed soil due to the current flowing in the ground fifty feet from a lightning strike. I am skeptical that the rebar wire ties will support the sort of current generated by a lightning strike. The limited contact between crossed rebar does not inspire confidence as well. I can imagine a scenario where the rapid vaporization of moisture in the concrete could rupture the concrete and weaken an otherwise solid foundation. To qualify the use of a UFER based on the low resistance characteristics is a mistake if it cannot support the current generated by a lightning strike. Since the UFER is unexposed, it is not subject to testing or inspection after a lightning strike in order to verify its integrity. I think it is wise to rely on made electrodes of simple, reliable construction and known current capability that are easily inspected (at least by a few minutes work with a shovel). We should not focus on one, easily measured characteristic of the ground system to the exclusion of others.

Cheers,