Fire Safety of Roof Systems

Hazard profile

Large roof areas are exposed both externally – to flying sparks, burning debris from neighbouring buildings, or lightning strikes – and internally, where combustible insulation or steel trapezoidal deck construction with unprotected cavities is used. A smouldering fire once established within a roof structure often remains undetected for a long time and can spread over large areas before becoming visible from outside.

Structural and material measures

Key factors include classifying the roof covering by its behaviour under external flame exposure, avoiding open joints and cavities, fixing insulation to steel decking in a fire-safe manner, and maintaining separation distances to rooftop structures such as roof lights or photovoltaic installations. During refurbishment, particular attention must be paid to the compatibility of new roof build-ups with the existing structure.

Insurance relevance

Roof fires are among the most loss-intensive events in industrial and commercial buildings, as they are often extensive and make repairs lengthy. During a survey, risk engineers assess the roof build-up, the condition of the covering and classification evidence as a key component of loss estimation.