Are Your Ground Rods Far Enough Apart? What the NEC Informational Note Actually Says
Ask any electrician about driving ground rods and you will get a story. Nobody enjoys it, the work is hard, and in places like Texas where shale and limestone hide just a few feet below the surface, it can turn into a full afternoon. But beyond the war stories, there is a real technical question that does not get talked about enough: are most electricians spacing their ground rods correctly?
James Adams with ABR Electric recently went down that rabbit hole, and what he found buried in the 2020 National Electrical Code is worth knowing.
The Code Minimum vs. What Actually Works
Most electricians know that when you install two ground rods, the NEC requires them to be at least six feet apart. That is the rule, and most guys hit six feet and call it done.
But tucked into section 253.83 of the 2020 NEC is an informational note that says something different.
“The paralleling efficiency of rods is increased by spacing them twice the length of the longest rod.”
So if you are using standard eight foot ground rods, that informational note is saying the rods should be placed 16 feet apart, not six, to actually work as a parallel system and not just two rods sitting close enough together that their electromagnetic fields overlap.
James puts it plainly:
“All these years I didn’t realize it was there. It’s like, hey, try that rod, make it six foot one inch, by the beam we’re good.”
Why Does Spacing Actually Matter?
Ground rods work by dispersing electrical energy into the earth. Each rod has an electromagnetic field around it that reaches out into the surrounding soil. When two rods are placed too close together, those fields overlap and the second rod does not add much benefit. You essentially have one effective ground instead of two.
Spreading the rods farther apart gives each one its own zone of influence in the soil, which is what actually improves the grounding system’s performance.
James raises a fair question about why this matters for the homeowner:
“If we did this and had greater paralleling efficiency, how would it benefit the homeowner or our client? How does it make their system better?”
He also connects it to surge protection, pointing out that a better path to earth in theory means better performance from whole home surge protectors. When a lightning strike or power surge hits, you want that energy to have the clearest possible path into the ground.
“We are in theory creating a much better path to earth.”
So Why Is It Just an Informational Note?
This is the part that frustrates James, and honestly it is a reasonable frustration. The NEC went through the work of researching this, had engineers figure it out, and then put it in the code as a note rather than a requirement.
“Why would they put the informational note here and not enforce it? If they’re saying it’s increasing the efficiency by spreading these rods apart, then why not make that the standard?”
He brought this up with a building inspector who actually complimented ABR Electric’s crew for driving their rods at a slight angle away from each other. That is a smart field practice because if two eight foot rods are only six feet apart and driven straight down, they are almost crossing underground. Angling them outward at least keeps them separated where it counts.
The Ground Rod Story Every Electrician Has
No conversation about ground rods is complete without a field story, and James has a good one.
“We were driving at an angle because it was in a place where there was shale or limestone about four feet down. All of a sudden my helper goes, hey, something just poked me in the foot. The ground rod had skipped off the shale and curved and come back up behind him. He stepped back on the end of that thing poking back out. It had done a u-turn.”
It is funny in hindsight, but it also shows how unpredictable ground conditions can be and why this part of an electrical installation deserves more attention than it usually gets.
The Bottom Line
The six foot minimum gets you past inspection. But the informational note in the 2020 NEC is pointing toward something better. Spacing your ground rods at least 16 feet apart, twice the length of an eight foot rod, gives you a genuinely more effective grounding system, not just one that passes code.
“Whether they’re going to have that six foot interval as the standard or greater, why mention double the length of the rods at all? What’s the context for us as electricians installing the system that’s bonded to earth? Why does it make a difference?”
That is a question worth asking, and one that ABR Electric is clearly thinking about.
Have questions about your home’s grounding system or electrical panel? Reach out to ABR Electric call 214-690-1941.