LIGHTNING PROTECTION FOR BARNS AND OUTBUILDINGS
Back in the days when the average barn was just a stone and wood structure, the only protection from lightning it might have had was a lightning rod, which was typically a tapered metal spike (known as the “Franklin rod”) mounted onto the roof using a copper tripod and braided cable or wire. If lightning struck, the rod was there to conduct the energy into the ground, bypassing the structure. But a lightning rod alone does not provide complete protection from damage. Electricity from the strike can easily side-flash into the structure, potentially causing barn fires as well as the death of any animals inside.
The modern barn, however, is much more likely to be a complex building, with electrical systems, plumbing, metal door or window frames, concrete rebar and other structural elements that contain metal—all of which could conduct the electricity of a lightning strike throughout the interior of the structure. That’s why modern building codes require that a number of safety systems be in place to protect against the possibility of damage from a lightning strike.
“While the theory behind Benjamin Franklin’s invention still holds true, lightning protection is a science that has evolved to meet the needs of modern structures,” says Kimberly Loehr, communications director for the Lightning Protection Institute.
“A lightning rod, d, now known as an ‘air terminal’ or ‘strike termination device,’ is only one component of a complete lightning protection system. In addition to a network of strike termination devices or air terminals on the roof, a complete lightning protection system includes down conductor cables, copper ground rods or plates, bonding devices to ensure electrical continuity and surge protection devices for incoming power sources and communication lines.”
If your barn was built recently, by licensed contractors, it ought to meet current building and safety codes, including lightning protection. If, however, you have an older structure, even if it’s been updated over the years, it might be a good idea to have your barn inspected by a professional. Especially if electrical storms are common in your area, it might be worth the costs to upgrade the lightning protection systems in your barn to contemporary standards.
“Although the principles of lightning protection haven’t changed, a lot of those old termination systems will probably need to be updated,” says Loehr, who suggests consulting the safety standards written
by the National Fire Protection Association (NFPA).
This type of work is generally best left to a professional. And once a lightning protection system has been installed, it’s a good idea to have it inspected annually to make sure that weather conditions, such as high winds, have not damaged any of its components. Even re-roofing can affect a system’s performance, and any metal components that are buried in the ground will deteriorate over time.
Even the most advanced lightning protection systems may not eliminate all damage from a direct strike. But it may mean the difference between a few blownout appliances versus having the building burn down.
UPGRADES: A modern lightning protection system includes conductor cables, ground rods, bonding devices and surge protection devices.