Each spring, millions of properties are damaged or destroyed by lightning. A single bolt of lightning can generate heat in excess of 50,000 degrees F which can spark fires or cause surging through electrical circuitry. Lightning losses often include damage to expensive home electronics, as well. Homeowner insurance claims from lightning strikes continue to rise, with the average claim costing over $4,000. Fires caused by lightning represent a serious threat to life and property, but the risk is often overlooked by home and business owners. A lightning strike to an unprotected structure can cause catastrophic damage. Fortunately, there are relatively simple and inexpensive measurers that can be taken to substantially reduce the chances of lightning-related damage and disruptions.
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. The system provides a network of low resistance paths which provide grounding without impact to the structure or its occupants.
According to the National Weather Service, there are three main ways that lightning enters buildings: 1) a direct strike, 2) through wire or pipes that extend outside the structure, and 3) through the ground. Regardless of the method of entrance, once inside the structure, the lightning can travel through the electrical, communication, or data wiring, along with plumbing, gas or process piping systems. Lightning can also travel through structural steel framing and reinforcing rods in concrete walls or flooring.
On the outside of the structure, lightning can travel along the outer shell and may follow conductive metal vents, roof drainage elements and external supports as it seeks a path to ground.
While the concept behind lightning protection is relatively simple, the requirements for proper installation are specific and often complex. Specifications, technical information and installation methods should comply with LPI-175, NFPA-780 and UL-96 A, which are the three nationally recognized safety standards for lightning protection installation:
Dispelling Myths
LPI stresses that understanding lightning is a good first step for homeowners to take when considering protection. Considering lightning inspires awe and wonder, and also fear, it is important to separate fact and fiction when it comes to lightning safety.
Lightning is not deterred by surge arresters, suppressors and “whole-house protectors.” Contrary to popular belief, surge protection devices cannot protect a structure against direct lightning strikes. While these devices are important components of a complete system to protect incoming utility lines against infiltration, on their own they do little to protect a home from lightning. However, when combined with a structural lightning rod system, (air terminals, bonding and grounding) they can prove a valuable and effective means of protection.
Lightning rods do not attract lightning. Another myth commonly associated with lightning is that lightning rods attract lightning. In fact, a lightning protection system acts more as an interceptor of lightning, rerouting a strike and providing a safe path to ground for discharging the dangerous electricity.
Tall trees do not protect homes from lightning strikes. The problem with a home nestled under a group of trees is where the best ground path for the lightning might be. Common metallic grounded systems within a home (electric, phone, gas, water) may provide a preferable grounding medium for the lightning. Therefore, lightning can actually “side-flash” from a tree and enter a home as it seeks a more conductive path to ground.
Lightning likes technology. As the world becomes more and more tech-savvy, the losses from lightning strikes are increasing. Today’s homes and businesses have more electronic equipment than ever before, and metal building components are on the rise as well. Internal systems lead lightning toward more valuable, often irreplaceable items and people in close proximity.
A lightning rod on a chimney will not provide adequate protection. A single rod or single air terminal is not adequate to protect a structure against lightning. A complete system which complies with safety standards is needed to provide safe and effective lightning protection performance. Improper installation can lead to serious and dangerous consequences for the homeowner.
Lightning rods are not unsightly on chimneys and roofs. An experienced lightning protection contractor will ensure the lightning protection system will not detract from the structure and will blend aesthetically with the roof and chimney composition.
A professionally installed lightning protection system can provide security and peace of mind. In many cases, homeowners can expect to pay less for lightning protection than a typical security system. For homeowners at risk, lightning protection is an important amenity that can provide a big return on a small investment.
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Kim Loehr, a communications consultant for LPI, partners with the NOAA Lightning Safety Awareness Team and is a member of NFPA’s Building Fire Safety Systems Section. She is also a registered course provider with the Lightning Safety Alliance (LSA) and its national Continuing Education Service (CES). She can be contacted at kiml@lightning.org.
