Lightning is a powerful, destructive force of nature and will strike a building regardless of its type of roofing. Metal roofs do not attract lightning strikes; nor do metal roofs protect a building against lightning. The only way to protect a building is with a properly designed and installed lightning protection system (LPS).
Still, the type of roofing is one of several risk factors affecting the threat lightning poses to a structure, according to the National Fire Protection Association (NFPA) 780 – Installation of Lightning Protection. The recognized North American standard includes a Simplified Risk Assessment procedure to help designers determine if an LPS is recommended for a building. It recognizes that, when a lightning strike does occurs, a building has less risk of being devastated by fire if it has a non-combustible metal roof. (See sidebar.)