What is a characteristic feature of a rollover in fire behavior?

The characteristic feature of a rollover in fire behavior is a rapid spread of fire across surfaces. Rollover occurs when unburned fuel gases accumulate in the upper levels of a compartment or area and reach a temperature sufficient for ignition. When these gases ignite, it causes a flashover effect where flames can quickly spread across the ceiling and along surfaces. This phenomenon is often observed in fire scenarios, particularly in enclosed spaces, where the congestion of heat and gases leads to a sudden and dramatic propagation of flames, making it a critical aspect to understand for fire safety and firefighting tactics.

While gradual build-up of heat, a sudden explosive increase in fire, and a momentary pause in growth describe different aspects of fire behavior, they do not capture the essence of rollover as accurately. Rollover is specifically tied to the quick ignition of previously accumulated flammable gases, leading to rapid advancements of flames, making it essential for firefighters to recognize and address this behavior promptly.