As Commercial Roofing Materials Change, So Do Risks

July 28, 2010

Commercial roofing, already complicated, is getting more so as new types and materials are being introduced, according to a leading engineer who specializes in assessing roof losses for insurers.

Kenneth R. Gilvary, a senior engineer with Dallas-based Haag Engineering, says green technology and new building standards are changing the roofing industry and claims professionals must keep up.

Gilvary was at a recent Property Loss Research Bureau Conference (PLRB) to help claims adjusters learn the complications of the various types of commercial roofs and how to determine wear-and-tear from covered losses on them. He discussed the challenges in a recent video for Claims Journal, which can be viewed on Insurance Journal TV.

“Commercial roof losses aren’t necessarily more common. They’re just a lot more expensive and a bit more complicated. The reason that they’re more complicated is simply that there’s a lot of different styles and techniques that are used out there, and it’s difficult to see, while you’re just standing on the roof, what all those layers are,” Gilvary says.

Commercial roofs vary in their construction and materials in many ways. There is a built-up roofing system, which is layers of felt that are sandwiched together with asphalt to actually build up a roof system. Another is a modified bitumen system, which is asphalt modified with a rubber to make it more tough and durable.

Another is a thermo-plastic roofing, a PVC or TPO style, which is a single-ply roofing material that can actually be melted together while it’s being applied to the roof.

Still another is what’s called a thermo-set plastic roofing, which is also a single-ply roofing system, but it can’t be melted together. This type of system is very elastic, and so it can stretch for long distances and help accommodate some building movement, according to Gilvary.

Other roofs are made from spray-applied polyurethane foam, often referred to as SPF, which is sprayed over an entire roof including the flashings, the joints and the whole building. A final type of most common roofing system for commercial roofs is the metal-roof system, which is mostly used on sloped areas.

Wind damage and hail damage are typically readily discernible from weathering on a roof system.

“Wind damage is going to be a pulling, a tearing, a lifting of the roof system, and it’s going to be the most severe at the corners and the edges of the roof, where the wind forces are the strongest. Hail is going to actually cause an impact and a trauma on that roof where that hail impact hits. It’s distinguishable from other things because hail is going to have a variety of sizes of the impact damage, it’s going to have a predominant direction from the storm, and it’s going to be randomly distributed over the entire roof,” says the engineer.

On the other hand, wear and tear on a roof is going to more spread out over the whole roof system, and it’s more severe where there’s higher exposure to sunrays.

Gilvary believes that green construction and building standards are changing what roofs are like and changing the entire industry. As we move more toward buildings that are more efficient, we’re trying different types of roof systems that are out there,” he says.

One emerging roof type uses more white-colored roofing, which can be more economical in terms of cooling. “We say white is the new green.”

Vegetative roof systems are becoming more popular and present unique challenges. Most roofing is about shedding water off of the roof, and so most of the technology and the detailing used is about getting the water off the roof so that it does not cause deterioration. But green roofing actually is intended to keep the water on the roof or to channel it through some sort of a system.

“That creates a lot of challenges because when you keep water on the roof, number one, you’re going to make it a whole lot heavier, and you’re going to have a lot of soils and stuff that are heavier. So design engineers need to keep that in mind when they’re designing the structures. We also need to consider different materials for the green roofing that’s going to be more resistant to moisture,” the roofing expert explains.

Gilvary believes the insurance industry must be prepared for more claims from vegetative roofing and new roofing materials.

That’s just a given. We have a lot of systems that we use now that have been developed over the years but the vegetative roofing is a relatively new thing, and so there’s a lot of new materials, new ideas, new products, and new processes for installing those products that we’re trying to figure out. So as an industry, we’re going to make mistakes, and those mistakes are going to end up leading to claims, of course,” he says.

The Claims Journal interview with Gilvary may be viewed at Insurance Journal TV.

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