In buildings with four or more stories, how steep must the roof slope be for only one stairway to extend to the roof surface?

• A. 25 percent slope
• B. 30 percent slope
• C. 33 percent slope
• D. 45 percent slope

Answer: (C)

In buildings with four or more stories, the requirement for a roof slope pertains to the accessibility and safety for occupants in case of an emergency. A roof slope of 33 percent (which is equivalent to a 3:12 pitch) is established as the minimum necessary to ensure that the roof drains effectively and reduces the risks associated with snow and water accumulation.

This specific slope allows for the design of a single stairway extending to the roof surface without compromising safety and functionality. If the roof were to be less steep, such as a 25 percent or 30 percent slope, it might not effectively facilitate drainage and could lead to hazardous conditions. A 45 percent slope would be too steep for practical use as it would create challenges for accessibility and safety for individuals navigating the stairway.

Thus, having a roof slope of 33 percent is crucial because it maintains an appropriate balance of safety, drainage, and accessibility in compliance with North Carolina Building Code requirements.