Guards at the open sides of stairways must not allow passage at a sphere of what diameter?

For guards at the open sides of stairways, the requirement that they must not allow passage of a sphere with a diameter of 4 inches is based on safety regulations aimed at preventing small children or objects from falling through gaps. The 4-inch diameter is significant because it reflects a commonly accepted safety standard in building codes to ensure that individuals, especially children, cannot slip through the openings.

This specification aligns with maintaining a secure environment where guard rails effectively prevent accidents. A sphere larger than 4 inches is less likely to fall through, ensuring guards provide sufficient protection. The choice of 4 inches is based on a balance of aesthetics and functionality, focusing on the safety of users in both residential and commercial stairway design.

Understanding this standard is critical for inspectors when assessing the safety features of stairways during evaluations or construction projects, ensuring compliance with building codes and enhancing overall safety.