I have never given this any thought untill I ran across a site talking about how a soils ph affects how long a ground rod will last.But I've also never gone back to a job and pulled one out to see what condition it was in.When I go to a supply house and buy a ground rod,it doesn't come with any paperwork from the manufacturer with installation instructions,warranty,or anything else.
If you can go to a demolition site and see if you can pull up a ground rod. Check on how long the system was there ( a permit history search may be a good start). In my travels around the country, I have pulled up a rod that could have been reused that had been in the ground for over 20 years. I also pulled one up that was rotted out in less than two years. It all depends on the soil and climate and maybe the use of the location. In this area, it's not usually a problem.
Re: Ground Rod Longevity#83570 02/06/0311:30 PM02/06/0311:30 PM
There are many different types of steel and coatings. If you are to believe the manufacturers, modern zinc-aluminum coatings give steel with very long life in ground. If you don't trust these, there's slow rusting steel. Unlike stainless the surface will soon rust, but as the layer of rust builds up, the process slows to a near halt.
Re: Ground Rod Longevity#83573 02/07/0305:26 PM02/07/0305:26 PM
Not only do we need to be aware of the life of a rod, but any abuse that it has taken, like a lightning hit. A rod that has been driven into a sandy soil, when hit by lightning, will have glass buildup all along the length. Glass is not very conductive.