A row of detectors is required within how many inches of a ceiling peak?

A row of detectors is required within how many inches of a ceiling peak?

• A. 24 in.
• B. 12 in.
• C. 36 in.
• D. 48 in.

Answer: (C)

On vaulted or peaked ceilings, detectors need to be placed so they are within 36 inches of the highest point. This placement takes advantage of the way smoke and heat rise and collect at the ceiling apex, so a detector near the peak will notice smoke sooner than one farther away. The required maximum distance is 36 inches, which is why this option is the best answer. Distances like 48 inches would exceed the limit and could delay detection, while smaller distances (12 or 24 inches) meet the requirement but are not the maximum distance specified.

On vaulted or peaked ceilings, detectors need to be placed so they are within 36 inches of the highest point. This placement takes advantage of the way smoke and heat rise and collect at the ceiling apex, so a detector near the peak will notice smoke sooner than one farther away. The required maximum distance is 36 inches, which is why this option is the best answer. Distances like 48 inches would exceed the limit and could delay detection, while smaller distances (12 or 24 inches) meet the requirement but are not the maximum distance specified.