Final answer:
Horizontal guards at raised floor areas must prevent the passage of a 4-inch diameter sphere to comply with safety regulations, preventing potential falls or injuries.
Step-by-step explanation:
The question pertains to the building codes and safety regulations concerning railings at raised floor areas, balconies, and porches. Horizontal guards for these areas must include intermediate rails or ornamental closures that prevent the passage of a specified size object to ensure safety.
In building safety terms, this specification is important to prevent accidents, such as falls or objects being dropped from heights that could endanger people or property below.
Typically, building codes require that the guards do not allow the passage of a 4-inch diameter sphere, which equates to the size of a small object that a child's head could not pass through, therefore minimizing the risk of accidental falls.
Horizontal guards at raised floor areas, balconies, and porches should have intermediate rails or ornamental enclosures that do not allow the passage of a {2.3125-inch} diameter sphere.