How far do division walls (fire walls) generally extend above the roofline?

How far do division walls (fire walls) generally extend above the roofline?

• A. 12 inches
• B. 18 inches
• C. 24 inches
• D. 6 inches

Answer: (B)

Fire walls are meant to act as continuous vertical barriers that separate occupancies and resist fire exposure. To keep that barrier effective at the roofline, it must extend above the roof by a minimum amount. This added height helps prevent flames, heat, and embers from crossing over the top if wind-driven fire or roof conditions occur, preserving the separation through the roof area or any parapets. The standard minimum extension is 18 inches above the roofline. If a parapet or other roof feature is present, the wall may extend to or through it, but 18 inches is the common baseline. A shorter extension would weaken the barrier, while a much taller extension isn’t typically required unless a specific code or condition demands it.

Fire walls are meant to act as continuous vertical barriers that separate occupancies and resist fire exposure. To keep that barrier effective at the roofline, it must extend above the roof by a minimum amount. This added height helps prevent flames, heat, and embers from crossing over the top if wind-driven fire or roof conditions occur, preserving the separation through the roof area or any parapets. The standard minimum extension is 18 inches above the roofline. If a parapet or other roof feature is present, the wall may extend to or through it, but 18 inches is the common baseline. A shorter extension would weaken the barrier, while a much taller extension isn’t typically required unless a specific code or condition demands it.