High-Performance Cover Boards Help Reduce Potential Fire Damage Posed by Photovoltaic Paneling
As you consider adding solar paneling to your roof, make sure you’re setting up your building safely. Solar panels save on utility costs, support sustainability objectives, and help attract tenants. But they can also be a source of potential fire damage. However, it doesn’t mean you need to scrap your photovoltaic (PV) paneling project altogether. Just as you plan to handle and reduce the risks of other potential fire sources, you can also do the same for your solar roofing.
Like Any Rooftop Electrical System
According to PV Magazine, there are no hard numbers available on the frequency of solar panel fires each year, mainly because the National Fire Data Center classifies them within a blanket “other” category of causes—which means we don’t know exactly how bad the problem is. Though data is still limited, recent cases indicate that PV paneling has been the source of rooftop fires previously.
Perhaps most famous is a 2019 multi-million dollar lawsuit that Walmart brought against SolarCity (a Tesla subsidiary) after separate roof fires broke out across 7 of their 240 buildings with solar roofing installed. Amazon also joined the suit, noting a similar fire even occurred on one of its 11 warehouse sites, and a settlement was eventually reached for an undisclosed amount.
Not only can solar panels potentially start fires, but they can also aggravate a fire started elsewhere in your building and further threaten the very structure of a building. The cause for potential concern is twofold: catching fire within the panel itself or acting as a reflector to intensify a fire already burning inside the building.
Solar Power World publication explains that, “when fires do happen, the cause is often the same as any other kind of electrical fire: old, worn-out components, power surges, wind or lightning, bad design, or faulty installation.” And it is especially important for larger commercial solar roofing systems to be installed with ample space between panels to give firefighters adequate access between the panels and the roof deck if necessary.
Notes the National Fire Protection Association (NFPA), any electrical fault can be a source of fire, “since electrical breakdown—leading to arc faults, ground faults, and short circuits—can occur anywhere across the system.” For this reason, mitigating risk of fire spreading across the roofing assembly is imperative.
The experts suggest looking into the durability of the paneling materials when making your selection, and the same goes for the substrate below it. Simply put: The materials you include in your roofing assembly can help mitigate increased risk of fire damage on your photovoltaic roof.
Including a cover board (roof board inserted between the roof membrane and insulation) in your roof assembly provides additional strength to help support the weight of the solar panels. With insulation being the costliest part of the assembly to replace, the cover board helps extend the life of your roof, while also keeping repair costs down. Roof boards attached to the deck in the cover board position helps keep external sparks from igniting beyond the roof to the rest of the building below, while those attached in the thermal position (below the insulation) help keep organic roofing materials from further fueling an internal blaze.
But not all cover boards are created equal. Those made with gypsum offer superior fire mitigation, as cover boards that include gypsum can help slow a flame’s spread. Naturally occurring in crystal form, pure gypsum (known as calcium sulfate dihydrate) includes two molecules of crystalized water. The same is true for synthetically made gypsum, too.
These naturally occurring properties also mean that gypsum is made of 21% water that is chemically combined with calcium sulfate, which remains inert up to temperatures as hot as 2,200o Fahrenheit. In the event of a fire, this chemically combined water gradually releases as vapor—oxidizing the remaining calcium sulfate, slowing the calcination process, and leaving the unexposed side at about 212 o F until all the water is gone—thus slowing the burning process.
DensDeck® Prime Roof Board is a high-performance non-combustible cover board made from durable gypsum with a strong fiberglass mat. When added as a cover board beneath photovoltaic panels, it helps maintain a strong foundation and reduces the risk of solar rooftop fire. To learn more about how DensDeck Prime could help keep your building safe, visit DensDeck.com.
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