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Residential architects who specialize in the hot, humid, southern climate

Lightning Protection


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Another dramatic afternoon storm rolls in with an impressive lightning show, as I am writing specifications for a lightning protection system. We recommend lightning protection systems to all of our clients because of our intense storms. Damages can range from loss of electronic equipment, to damaged chimneys to total destruction by fire.

According to the National Weather Service, central and southern South Carolina average 50 to 70 days with thunderstorms each year with approximately 395,962 lightning hits to the ground. South Carolina is ranked 12th in the nation in the number of lightning hits to the ground. The Insurance Information Institute reported in 2013 that South Carolina ranked 8th in the nation in lightning damage with 4,011 claims with insured losses of over twenty-three million dollars.

“The good news is most personal injury and property damage caused by lightning can be prevented.” Says Leslie Chapman-Henderson, CEO and president of the Federal Alliance for Safe Homes, Inc. (FLASH). For personal safety, heed the adage “When thunder roars – go indoors.”

“Home and business owners needn’t take their chances with lightning,” explains Bud VanSickle, executive director of the Lightning Protection Institute (LPI). “A professionally installed lightning protection system which meets U.S. Safety Standards … will prevent lightning damage by providing a safe electrical path into the earth for lightning’s destructive energy.”

A system designed to meet National Fire Protection Association 780 Lightning Protection Code has five basic components:

  •  Air terminals, or lightning rods which are made of copper or aluminum. They are mounted on the highest points of the roof and chimney to intercept the lightning strike.
  •  Cable conductors, made of braided copper or aluminum cable which run from the lightning rods to the ground rods and connects to other parts of the system.
  •   Ground rods which are driven at least ten feet into the ground and direct the lightning’s energy away from the building.
  •  Bonding points connecting other metals in the building to the cable conductors and ground rods. These connection are important to prevent side flashing.
  •  Surge arrestors and suppressors installed at the electrical panel(s) to prevent over-voltages caused by a lightning strike near a power line. Additional surge protectors should be installed at electronic equipment.

While lightning protection systems can be installed at any time, it is best to install it during new construction because it is easy to hide the cable conductors in the walls. The costs vary depending on the size and complexity of the building. VanSickle estimates that the system will cost about one percent of the building’s total construction cost.  The costs can be offset with potential home insurance savings and the peace of mind that your home is safe from lightning.