Here are some quick tips for inspecting rod and pipe electrodes. As a home inspector college (internachi.edu), we continually review and revise our curriculum. And we’ve updated some training content within the free, online How to Perform Residential Electrical Inspections Course with the following inspection tips that you might be interested in using during your next home inspection:
Rod and pipe electrodes must be at least 8 feet in length to be considered a grounding electrode.
Grounding electrodes of pipe or conduit must be at least 3/4-inch (metric designator 21) and, if made of iron or steel, must have its outer surface galvanized or metal-coated for corrosion protection.
Rod-type grounding electrodes of stainless steel and copper or zinc-coated steel must be at least 5/8-inch in diameter unless listed.
The rod and pipe electrodes must be installed so that at least 8 feet of length is in direct contact with soil. They should be driven at least 8 feet into the ground. They could be driven at an angle not to exceed 45 degrees from vertical or buried in a trench at least 30 inches deep.
The upper end of the electrode should be flush with the ground or just below ground level so that the end and attachment are protected from damage.
Pipe electrodes are rarely used today. The most common electrode is a listed 5/8-inch (15.9 mm) copper-coated steel rod.
If a micrometer or similar device is not available, a home inspector shouldn’t guess on the rod diameter. If visible, you may be able to confirm by looking at the listing marks which may indicate that the rod complies with the diameter requirements of the National Electric Code (NEC). Listing agencies CSA, ETL, MET, and UL, will mark rods that are greater than ½ inch in diameter and that have the correct minimum amount of coating.
The listing mark must be stamped in the top foot of the rod. If you’re inspecting a new home under construction, you may want to ask the contractor to leave a shovel full of dirt away from the rod with the listed marking showing. This is one way to check the rod
Yep. I find that code is often written poorly. Code doesn’t require all rods and pipes to be marked. The language in the text is what the code actually states. It seems that code allows for two ways a grounding rod to meet the requirements: it can be 0.625 (5/8-inch) or larger in diameter, or it must be listed and not less than ½ inch. Then, there’s the issue of the actual diameter, because some identified 5/8-inch rods are nominally 5/8-inch which means that they may actually be smaller than the required 0.625 inches (15.9 mm) and do not meet Code. But those very technical things and issues are beyond what a home inspector checks. But I like the discussion.
Good information but little is subject to verification since it may not even be visible if installed correctly. Diameter will be tough if the end is peened over from driving and length would be a guess at best.
You may want to add what to look for when inspecting a new CEE or Ufer ground.
Yep. During a typical home inspection, in my experience, I look for the grounding rod, acorn, and move on. Unlike a code inspection, my home inspection is mostly observations of what’s readily visible. And a notation and an inspection image. Such as the following:
It seems like many of the photo’s on this forum of ground rods (including those in post #6) the 8’ rod is almost never flush with or below the surface of the ground. Is that something that a HI typically reports?
That’s different than here in the US. Two 8’ rods (can be 1/2" if listed) minimum 6’ apart. Continuous GEC to first rod, bonding jumper to second rod is permitted. In many instances in new construction with the CEE being required rods are becoming obsolete.
