For Group I-3, F, H, or S occupancies, guards must not allow the passage of a sphere greater than what diameter in non-public areas?

In Group I-3, F, H, or S occupancies, building codes stipulate that guards (railings, barriers, or other structures) should be designed to prevent a sphere greater than 21 inches in diameter from passing through in non-public areas. This requirement is specifically set to ensure safety and to mitigate risks associated with larger openings that could allow people or objects to fall or be drawn through the guard.

The reason for this particular measurement is that a diameter of 21 inches represents a size that can reasonably encompass large objects or even the torso of a child, which is a common consideration in safety codes to protect vulnerable populations. This standard helps ensure that occupants are adequately protected from potential hazards in these specific occupancy types, where the nature of activities and the occupants may be at higher risks.

In contrast, the other specified diameters do not align with the established safety guidelines for these occupancy types. Hence, understanding the rationale behind the 21-inch measurement is crucial for recognizing its application in practical scenarios involving building safety and compliance.