On Thu, 24 Jan 2013 01:35:34 -0800 (PST), Robert
wrote:

On Jan 24, 2:05 am, nestork wrote:
I think that if there was good evidence that lightening rods DIDN'T
work, we would have heard about the controversy by now. If tall
building are all equipped with lightening rods, that's good enough
evidence for me to believe they do work.

Obviously, you want to ensure that you have a pretty massive cable to
transfer all of that current around the house and into the ground. But,
I'd rather fry a $300 cable than have lightening set my house on fire.

I'd put one in if it wuz my house.

--
nestork

The current may be many thousands of amps, but it only lasts
for a few thousandths of a second. Consequently, the conductor
doesn't have to be massive since the short conduction time
means shorter heating time. Something like #6 wire is usually
enough, even tho it may carry an instantaneous 50,000 amps
or so. This can be confirmed by checking the size of the
grounding wire at your service entrance. Local codes and the NEC call
out the required size.
As far as a previous poster commenting on "bonding to the
structure", keep in mind that most houses have wood, non-conducting
construction, and that doesn't apply..... If the structure has steel
girders, it is another matter.
The cables on the old farm house were braided copper as thick as my
thumb -but loosely braded of roughly 16 guage wire with an open core
to allow good air cooling. After a heavy strike there was obvious
signs of heating (the oxide coating changed colour, and in some places
cracked)