For peaked roofs, detectors must be spaced within how many feet horizontally of the peak?

• A. 1
• B. 3
• C. 5
• D. 7

Answer: (B)

Smoke tends to rise and collect near the apex of a peaked ceiling, so detectors must be placed close to that highest point to catch smoke early. The best spacing is within 3 feet horizontally of the peak, ensuring the detector senses smoke before it travels down the slope. If you go farther from the peak, smoke can accumulate at the apex and delay detection, increasing the risk of a slower alert. A distance like 1 foot is overly tight and may be impractical or trigger nuisance alarms, while 5 or 7 feet creates a detection gap near the apex. So, placing detectors within 3 feet of the peak provides the most reliable early warning.