When a roof meets a parapet wall, how many inches must the parapet extend above the roof line?

• A. 30 inches
• B. 32 inches
• C. 24 inches
• D. 18 inches

Answer: (A)

The essential idea is safety and edge protection: a parapet wall needs to rise enough above the roof line to reliably serve as a guard against falls and to help contain wind and debris at the roof edge. The minimum height specified is 30 inches, measured from the finished roof surface up to the top of the parapet. This ensures a substantial barrier even when workers are near the edge and helps satisfy fire separation and weather protection requirements. Anything shorter would not meet the standard minimum, while taller extensions aren’t required unless local conditions call for it.