How do insurance companies assess the risk of combustible roofs (with PV)

FM and other insurers use FM standards to judge if combustible roofs with PV are insurable. ZAG testing proves AllShield BarrierSheet makes them functionally non-combustible, giving engineers the certainty to approve safe, insurable solar rooftops.

FM only tests with FM Approved materials and assemblies. For existing roofs, the FM engineer decides whether a project is insurable. In practice, many insurers worldwide adopt FM standards as their reference for roof fire safety. This means that not only FM engineers, but also engineers working for other insurers, evaluate projects through the same lens.

Independent ZAG testing has proven that combustible roofs equipped with AllShield BarrierSheets become functionally non-combustible – even when photovoltaic systems are installed and the fire load is doubled (36 kW versus the standard 15 kW). These results provide engineers with solid, independent evidence that AllShield solutions deliver reliable fire protection in critical scenarios.

For insurers, this offers confidence that projects meet a comparable level of safety to FM Approved assemblies. For engineers, it provides the reassurance needed to responsibly approve and insure roofs that would otherwise be considered too risky. In short, our ZAG-tested solutions create certainty: existing combustible roofs can be transformed into safe, insurable systems that align with FM methodology and the expectations of global insurers.

ZAG test results

At ZAG test institute it was shown that existing combustible roofs with EPS and bitumen, when combined with BarrierSheets and AllShield Blue, become functionally non-combustible. No flame penetration occurred under the BarrierSheet, meaning no fire spread – even beneath PV modules. The system performs equal to FM Approved assemblies.

Role of the engineer

FM delegates deviations from standard assemblies to the FM engineer. With ZAG’s proven results, engineers of all insurers now have a solid basis to accept and insure existing combustible roofs.

Key takeaways

AllShield provides a proven solution that transforms combustible roofs into functionally non-combustible, insurable constructions – fully aligned with FM methodology and standards. This gives commercial teams and engineers the confidence to approve projects.