Exposed height of ground rod

[Scott Laird]

Please help settle something for me. I have been always been taught that the electrical ground rod must be driven fully into the ground near the main service panel with ground wire attached with acorn nut. The pole and connection should be below grade and not seen. A fellow inspector friend says no, no! He says the pole and connection should be visible and 4" above grade. Who's right?

[Jim Port]

The code requires 8 foot in contact with the earth. You cannot achieve that without the top being flush or below the surface unless a 10 foot rod is used. There is also a requirement that the top be flush or below the surface. If a longer rod were used the top could be exposed if protected from physical damage.

[Marc M]

JP has it correct...

[Scott Laird]

JP has it correct...

Thanks gentlemen, I knew I was right! But here's my other question-- As a home inspector, how can I determine the presence of a ground rod without digging up the client's property? Or do I just make a notation that existence of a ground rod could not be determined. Recommend electrician verify its presence. ?

[Gunnar Alquist]

Thanks gentlemen, I knew I was right! But here's my other question-- As a home inspector, how can I determine the presence of a ground rod without digging up the client's property? Or do I just make a notation that existence of a ground rod could not be determined. Recommend electrician verify its presence. ?

Scott,

In my area, Ufer has been the most common method of providing a grounding electrode since the 1960s. If you use a rod, generally two are now required (not really, but it gets into allowable level of resistance and the need for specialty testing equipment - so many electrical contractors around here just drive two).

If you suspect a Ufer, you might see the GEC going to the foundation in the crawlspace (assuming not a slab) or the garage. If the GEC is in the garage, it's supposed to be accessible , so it shouldn't be covered by a finished wall material (cover plate or open). If the GEC disappears into the ground, it's probably best to say that you see the GEC but cannot verify the presence of an approved grounding electrode.

My 3 cents.

[John Kogel]

You can give it a yank and determine if it is anchored to something. I say this because I have seen the cable corroded and loose, and one time I remember the end was broken off and just buried in leaves. I think maybe I tripped over it while checking the chimney. :D

I prefer to see the clamp above the ground and most inspectors would agree, including the muni inspector that did the occupancy permit. You can't tell me 6" more or less will make much of a difference, but a buried clamp is going to rust away in my Pacific NW climate.

What does work well is a horizontal plate buried about 2 feet down. I am not sure of the actual depth. Check with your local authority.

Before selling a previous property that we owned, I decided to remove an unauthorized panel in the workshop. It was about a 20 year old installation, 3-wire overhead to a shop panel, ground rod buried under leaf mulch. The Al grounding conductor was corroded down to a couple of strands and snapped off when I yanked on it. :(
In my part of Canada, the grounding conductor must be Copper, because of corrosion, no doubt.

[Jim Port]

Under the NEC an aluminum conductor should not terminate within 18 inches of the earth.

The clamp should be listed for direct burial . It should not be of a ferrous material . There should be no rust issues.

[Jerry Peck]

I prefer to see the clamp above the ground and most inspectors would agree, including the muni inspector that did the occupancy permit. You can't tell me 6" more or less will make much of a difference, but a buried clamp is going to rust away in my Pacific NW climate.

It makes it easy to see if above ground, but it also makes it easy to be damaged above ground ... any AHJ inspector worth their salt would agree.

Make it easy for the inspector to see? Then bury it below ground level and put a short 6" diameter PVC sleeve around it up to ground level. There are AHJ in South Florida which have that done.

[Scott Laird]

It makes it easy to see if above ground, but it also makes it easy to be damaged above ground ... any AHJ inspector worth their salt would agree.

Make it easy for the inspector to see? Then bury it below ground level and put a short 6" diameter PVC sleeve around it up to ground level. There are AHJ in South Florida which have that done.

Thanks everyone for the helpful information; and thank you Jerry for making this rookie look up the acronym for AHJ. I'm going to have to store it in my personal home inspector dictionary!

[Eric Barker]

I prefer to see the clamp above the ground..... You can't tell me 6" more or less will make much of a difference,

This is my opinion as well. Obviously I never would never amount to much as a muni inspector who was "worth his salt".

[Bill Kriegh]

Sometimes you have to limit your inspection to what is visible.

How do you know, for example, that a water supply line doesn't have an insulating union or non metallic chunk of pipe in a finished basement situation making the GEC unable to double as a bonding conductor for the water lines? How do you know that the chunk of copper wire or re-bar sticking out of a foundation qualifies as a UFER? (yeah, I saw one that had a hole drilled and the copper glued in with construction adhesive -only other problems alerted me to the fact the GEC wasn't one).

Sometimes you gotta work with what you've got.