Protecting Your Facility from Lightning

Lightning is a powerful force in nature. In fact, a single bolt of lightning can contain up to 100 million volts of electricity.[1] With that much power, the resulting damage can be extreme. Lightning can tear through roofs, damage walls and property, and cause fire. For a business, being forced to shut down operations for repairs and recovery as a result of lightning damage can be financially devastating. Certain commercial buildings (based on building code requirements, location, occupancy, frequency of thunderstorms, etc.) may need lightning protection systems installed to help keep them protected. In fact, some insurers require systems be installed.[2]Work with your insurer and agent or broker to determine if your business should consider adding such a program.

A lightning protection system does not, in fact, attract lightning. Instead, it redirects the bolt by providing a path of least resistance into the earth. The Lightning Protection Institute recommends that a business’s lightning protection system include the following components:

  • Air terminals: These rods are made of aluminum or copper and serve to intercept a lightning strike. Mount terminals evenly along your business’s roof.
  • Grounds: These are rods that are put into the earth around your building.
  • Main conductors: These are braided cables that connect the air terminals to the grounds.
  • Bonds: These are connection points between the main conductors and roof and ground points of the system. They help prevent side flashing (when lightning jumps between objects).

Lightning protection system

Even with a lightning protection system in place, your business can still suffer damage from lightning. If lightning strikes a power or utility line, the electrical current can travel along electrical, cable, or phone lines, causing power surges that can damage appliances and other electrical equipment. Using surge suppressors and arresters with connected equipment can help reduce this type of damage. Be sure to use only those approved and recommended by a reputable source, such as Underwriters Laboratories.

Finally, when installing your lightning protection system, contract with a certified professional and use only certified parts. Be sure to comply with local building codes as well as National Fire Protection Association and Underwriters Laboratories standards. By being proactive in protecting your business from lightning damage, you can help minimize the risk of loss.

[1] Insurance Institute for Business & Home Safety. “Protect Your Commercial Property from Lightning.” Retrieved from

[2] Underwriters Laboratories. “Lightning Protection Systems.” Retrieved from

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The illustrations, instructions, and principles in this material are general in scope and, to the best of our knowledge, current at the time of publication. No attempt has been made to interpret any referenced codes, standards, or regulations nor to identify all potential risks or requirements.