Partitions which do not extend to the ceiling and are within less than 18 inches from the ceiling are not considered to affect smoke travel and therefore do not warrant a reduction of smoke detection spacing.

Partitions which do not extend to the ceiling and are within less than 18 inches from the ceiling are not considered to affect smoke travel and therefore do not warrant a reduction of smoke detection spacing.

• A. True
• B. Not specified
• C. Only in some buildings
• D. False

Answer: (D)

Smoke movement near the ceiling changes when there are obstructions close to that height. If a partition doesn’t reach the ceiling but sits within about 18 inches of it, it can create a ceiling-channel that alters how smoke spreads and reaches detectors. Because detectors are designed assuming more open, unobstructed paths, these near-ceiling partitions can divert or slow smoke flow, meaning the original detector spacing could miss early smoke and delay detection. Therefore, saying there’s no effect on smoke travel and no need to reduce spacing isn’t correct. In spaces with such partitions, detector spacing typically needs to be adjusted to maintain effective early warning in accordance with the applicable fire alarm standards.

Smoke movement near the ceiling changes when there are obstructions close to that height. If a partition doesn’t reach the ceiling but sits within about 18 inches of it, it can create a ceiling-channel that alters how smoke spreads and reaches detectors. Because detectors are designed assuming more open, unobstructed paths, these near-ceiling partitions can divert or slow smoke flow, meaning the original detector spacing could miss early smoke and delay detection. Therefore, saying there’s no effect on smoke travel and no need to reduce spacing isn’t correct. In spaces with such partitions, detector spacing typically needs to be adjusted to maintain effective early warning in accordance with the applicable fire alarm standards.