What is the maximum angle allowed for risers to be sloped from the vertical under the tread above?

• A. 25 degrees
• B. 30 degrees
• C. 40 degrees
• D. 45 degrees

Answer: (B)

The maximum angle allowed for risers to be sloped from the vertical under the tread above is indeed 30 degrees. This standard is established to ensure safety and accessibility in stair design. A slope greater than this could potentially create a steep or unstable condition, making it difficult for individuals to navigate the stairs safely.

The 30-degree limit facilitates a more manageable ascent and descent, minimizing the risk of tripping or falling. Additionally, maintaining this angle aligns with the overall building codes that aim to create uniformity and predictability in stair construction, promoting safety for all users.

The other angles presented, such as 25 degrees, 40 degrees, and 45 degrees, would not conform to this safety guideline. Angles steeper than 30 degrees could lead to design issues, including increased risk of accidents, which is why they are not acceptable in stair design according to the North Carolina Building Code.