For a corridor 18 ft wide, what is the maximum spacing between visible notification appliances?

• A. 100 ft
• B. 50 ft
• C. 200 ft
• D. 150 ft

Answer: (A)

In corridors, the goal is to ensure every point along the path is within a practical distance of a visible alert, so people can see a strobe promptly as they move. The standard maximum spacing for visible notification appliances in corridors is 100 feet. An 18-foot-wide corridor fits within the typical range where this 100-foot spacing applies, because the coverage is driven by ensuring visibility across the width and along the length, not by the width alone beyond a certain point. Spacing devices farther apart (like 150 or 200 feet) could create blind spots where the notification isn’t immediately visible, while spacing them much closer (like 50 feet) would be unnecessary and raise costs. Therefore, the maximum practical spacing is 100 feet.