How do I ground a metal building or metal warehouse with metal frame sidings for proper inspection?

How do I ground a metal building or metal warehouse with metal frame sidings for proper inspection? - E&S Grounding Ask the Experts

PJ Inquired:
I bought a 40X24 Metal frame with metal sidings building. No Elec or plumb at present, maybe later.
Inspector requires grounding Metal Building. 1×5/8”x8’cu clad steel rod ok tied to Botton I-beam? I also plan to use a rebar in slab to tie to metal frame in another place.
Any advice would be appreciated.


The Answer:
You must have some excellent building inspectors where you are at, as it is rare to see them bother with grounding a building that has no electrical service.  It is of course the right thing to do.  Since your building does not have an electrical service, the grounding requirements are not under the National Electrical Code NFPA 70.  While there may be some other code that governs grounding of buildings with-out electrical service, we are not aware of it.  As such, whatever satisfy’s your inspector is probably all that you are legally required to do. 

E&S recommend 10-ft ground rods, as this allows you to have 8-ft of the rod below the 1.5-ft mark, and still have 6-inches of the ground rod above grade for bonding purposes.  The National Electrical Code (NEC) now requires two (2) of these rods (unless you can measure the rod and prove it is below 25-ohms resistance-to-ground) be installed at least 6-ft apart.  You may want to install two (2) rods, one each at opposite corners of the building.  Bond the steel frame directly to the ground rods using a solid #6 copper wire (or larger).   And yes, ideally the rebar in the concrete should be bonded to the metal frame of the building.  We recommend at the 4 corners.  Please see the NEC 2011 Handbook for illustrations detailing the bonding requirements of rebar and the steel frames of buildings, as well as how to properly install a ground rod.

We hope you find this information useful.  Feel free to contact us again in the future if you should have any further questions.

The Engineering Experts at E&S Grounding Solutions

Grounding & Earthing Below-Grade Electrodes, metal sidings, metal building, grounding a metal building, building steel

Related Posts

What Is Electrical Grounding? - E&S Grounding Solutions

What Is Electrical Grounding?

What Is Electrical Grounding? Electrical grounding or “Grounding” originally began as a safety measure used to help prevent people from accidentally coming in contact with electrical hazards. Think...

Read More
When is it necessary to put a disconnect switch in a residence with a 100, 200 amps, and where do you ground it to? - E&S Grounding Ask the Experts

When is it necessary to put a disconnect switch in a residence...

Greg Asked:When is it necessary to put a disconnect switch in a residence with a 100, 200 amps? and where do you ground it to? a rod water pipes or just to the panel?

Read More
Grounding of metal buildings - E&S Grounding Ask the Experts

Grounding of metal buildings

PJ Asked:Inspector requires grounding of metal building, I plan to use a rebar in slab to tie to metal frame in another place?

Read More
How exactly are airplanes electrically grounded? - E&S Grounding Ask the Experts

How exactly are airplanes electrically grounded?

Michael Asked:How are airplanes electrically grounded? Is a lightning protection system (LPS) effective if it is not grounded? If you install a lightning rod that is not grounded, is it more or less...

Read More