If exterior structures are being exposed to fire from the original fire building, how much of the actual required fire flow should be added for protection?

When exterior structures are being exposed to fire from the original fire building, it is essential to add a percentage of the actual required fire flow to better protect those structures from potential ignition, heat transfer, and fire spread. In this case, adding 25 percent of the actual required fire flow is considered appropriate for several reasons.

This addition reflects the need to account for the increased risk posed to adjacent buildings or structures, especially if they are close to the original fire source. A fire can easily spread to exterior surfaces through radiant heat, direct flame contact, or even structural involvement if there is inadequate protection. By adding this additional 25 percent, the fire service ensures that there is adequate water supply for both active extinguishment and the cooling of exposures, which is a critical tactic in preventing fire spread.

Furthermore, this figure is based on established guidelines in fire protection and tactical operations, which emphasize the importance of having enough water resources to combat not only the primary fire but also to provide necessary protection for neighboring properties, particularly in densely populated areas or where structures are closely spaced. The strategic allocation of this additional fire flow is essential to both safeguard those exposures and to improve overall fire control efforts.