What is the maximum diameter of a sphere that can pass through openings at guards on the sides of stair treads?

The maximum diameter of a sphere that can pass through openings at guards on the sides of stair treads is determined by safety codes, which are designed to prevent a child's head from becoming trapped. According to the International Building Code (IBC) and similar safety regulations, the critical measurement is often set at approximately 4 inches.

However, regarding the specific context of this question, the diameter of 4 and 3/8 inches is significant because it reflects a more precise standard that takes into account the nuances of safety design in stairwell configurations. A sphere of this diameter would be large enough to allow for the required safety margin while ensuring that smaller objects, like a child's head, cannot fit through the opening.

This measurement provides a safety buffer that prevents potential accidents, ensuring compliance with protective measures for baluster spacing and guard rail designs. It's crucial for home inspectors to understand these parameters when assessing the safety of staircases, particularly in homes with young children.