Simply walking on a tile roof can cause damage, so homes in regions prone to hail, hurricanes, tornadoes or high winds may want to consider a stronger roofing material. It’s important to note that while clay or concrete tiles have excellent fire resistance, there is much to be desired when it comes too performance. Given that asphalt shingles don’t conduct electricity and, as a petroleum-based product, are flammable, they aren’t the best choice for homeowners in lighting-prone regions.Ĭoncrete or clay tiles are naturally fire-resistant materials and typically come with a Class A fire rating. Here’s a brief overview of how common roofing materials perform when it comes to lightning and fire.Īsphalt shingles are one of the most common roofing materials, mainly due to the fact that they are the cheapest. What is the best roofing material for lightning? Unrated materials are unable to meet any of the above classifications. Once treated, they can typically achieve a Class B rating. For example, wood shakes typically fall in the Class C category (or unrated) if they are not treated with fire-resistant chemicals. It’s important to note that some roofing materials require additional underlying materials to achieve a "by assembly" rating of Class A fire resistance. Some roofing materials, such as wood shingles or shake, must utilize fire-retardant chemicals to achieve a Class B rating.Ĭlass C materials are effective against light fire exposure only and include reconstituted wood products such as plywood and particleboard. They provide the best protection against flame penetration as stand-alone roofing products with excellent resistance to surface flame spread without the need for chemical treatments or extra underlying roofing materials.Ĭlass B materials are effective against moderate fire exposure. Based on their performance in the UL790 test, roofing products are classified as either Class A, Class B or Class C–with a Class A rating being the highest.Ĭlass A materials have proven themselves effective against the most severe fire testing. To meet UL standards, roofing materials must provide a degree of protection against flame penetration to the underlying deck and the attic space without producing flying embers, or slipping from their installed position. Considered the national standard for a roof’s ability to withstand fire, the UL 790 test rates roofing material performance when exposed to fire sources originating from outside the building. If you live in a lighting-prone region, you’ll want to look for a roof that is made of non-combustible materials and has the highest Class A rating for fire.įounded in 1903, Underwriters Laboratories (UL) is a not-for-profit organization that independently tests and certifies products, including roofing materials. When lightning strikes a metal roof, the voltage and risk of fire are quickly contained since metal is conductive and provides the lightning strike with a direct path to the ground outside of the home. Made of highly conductive and non-combustible metal, lightning rods are designed to intercept the voltage from a lightning strike and provide a safe and direct path to the ground. Now, think about how a lightning rod works when placed on top of a building. Lightning produces intense heat, and often this heat can cause fires on the roof or inside the house after "jumping" from the roof to the first available path to the ground. If the roof is covered with combustible materials such as wood petroleum-based asphalt shingles, a lightning strike can easily start a fire. When it comes to lightning strikes and roofing, it’s all about fire prevention. In fact, as a non-combustible material with the highest Class A fire-resistance rating, metal roofing is one of the best materials for homes in lightning-prone regions. Extensive research has proven that metal roofing is no more likely to attract a lightning strike than any other type of roofing material.