If you have a metal roof, you may have received advice to “ground” it for protection against lightning. In this blog, local roofing contractor South Shore Roofing, Inc. shares a look at whether you need to ground your metal roof.
Let’s first take a look at how lightning behaves. Many people assume that a metal roof automatically attracts lightning because it’s made of metal. But this is a misconception. Lightning simply follows the path of the least resistance, which, in most cases, is the tallest grounded structure in the area. It could be a tree in the middle of a field or a tower in an urban area.
But what if your home happens to be the tallest structure in the area? If this is the case, a metal roofing system will protect your home from lightning strikes better than a wood shake or asphalt shingle roof would. In the event that lightning does strike a metal roof, its conductive properties will quickly dissipate electricity to the ground. Since standard roofing structures are built using wood and similar materials, it’s highly unlikely that electricity from a lightning strike will be conducted into your home.
Generally, you don’t have to ground your roof. International building codes do not require metal roofs to be grounded. However, local building codes may mandate grounding the roof depending on the following factors:
Topography — Large properties with varying topographical properties such as hills and flat lands may have increased likelihood of a lightning strike.
Building Size — The taller the structure is, the greater likelihood of a lightning strike.
Proximity to a Taller Structure — A man-made or a natural structure that’s taller than your home may decrease the chances of your home getting struck by lightning.
Frequency — If you home happens to be located in an area that’s prone to thunderstorms, grounding your home may be a necessity.