Residential Lightning Protection Guide

Lighting protection provides a path of least resistance for the lightning strike, preventing damage to the structure and its contents. This typically includes the installation of lightning rods (air terminals) on the roof, conductors to carry the lightning's electrical energy safely to the ground, grounding systems, and surge protection devices to safeguard electrical and electronic equipment from transient voltage spikes. Professional installation and adherence to safety standards are crucial for the effectiveness of a residential lightning protection system.

Helpful graphic showing the best lightning strike protection path through a home

Ground Rod Clamp

A ground rod clamp is a highly conductive copper clamp with one or two screws that connect the end of the cable to the underground ground rod.

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Ground Rod (Terminations)

A ground rod, also called a grounding terminal, is a long metal rod buried in the earth to guide lightning current into the ground, reducing the chance of fire and minimizing damage to home electronics. Ground rods are often made of copper or copper-bonded steel. A ground rod is typically driven into the ground to a depth of at least 8 feet.

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GEM (Ground Enhancement Material)

Ground Enhancement Material (GEM), also called Grounding Earth Material, can be used to improve the contact between the ground rod and the soil, and permanently increase soil conductivity where ground rods are buried in soil with poor conductivity. To install ground enhancement material, dig the ground rod hole wider than the ground rod to allow space for the GEM, create a slurry using the GEM, and pour the slurry filling the space around the ground rod. See your manufacturer's instructions for further details.

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Surge Arrester, Surge Protector, Surge Suppressor

Surge protection devices are used to protect electrical wiring, electronic systems, and equipment in a lightning protection system. A surge arrester, surge protector, or surge suppressor protects equipment by limiting voltage and diverting lightning current to ground. A surge arrestor is permanently connected or hardwired into the electrical system for an industrial system, commercial building, or home, and may be used in low to high-voltage applications. A surge protector is a plug-in device used to protect home electronics in low-voltage applications. A surge arrestor is designed to provide a higher level of protection than a surge protector. Multiple stages of surge protection may be used for residential homes, including permanently connected surge suppressors and plug-in surge protectors.

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Lightning Rod (Air Terminal)

A lightning rod, also called an air terminal, is a highly conductive metal rod with a tapered or blunt tip that is usually located at the highest point of a residential home structure to protect it against damage from lightning strikes. The lightning rod does not actually attract lightning but provides a way to prevent lightning from hitting the rest of the residential home structure.

Lightning Rod Mounting Base

A lightning rod mounting base holds the lightning rod in place on a structure and connects the lightning rod to a conductor cable using a single bolt tension clamp.

Copper Cable (Conductor)

Copper cable conductors for a lightning protection system consist of Class 1 or Class 2 braided copper wire.

  • Buildings under 75' tall use Class 1 copper cable with a minimum gauge of 2 AWG and a minimum gauge of 17 AWG per wire strand
  • Buildings over 75' tall use Class 2 copper cable with a minimum gauge of 00 AWG and a minimum gauge of 17 AWG per wire strand

Copper Cable Strap

Copper cable straps are used to properly secure lightning protection cables in place for better safety and organization.

Warning: When using this information to perform electrical work, call a licensed electrician and consult the NEC® or NFPA® for safety. All licensed electricians have passed examinations covering the National Electric Code®, know state and local building codes, and may carry insurance to cover damages. See also NFPA® 780-2017 Standard for Installation of Lightning Protection Systems.