For exemption, unprotected ceiling pocket depth must not exceed?

For exemption, unprotected ceiling pocket depth must not exceed?

• A. 6 in
• B. 18 in
• C. 24 in
• D. 12 in

Answer: (D)

In NFPA 13R for low-rise residential systems, there is an exemption that allows small unprotected ceiling pockets to be left without sprinklers. The limit for this exemption is 12 inches. That means pockets up to 12 inches deep can be exempt from protection, while pockets deeper than 12 inches must be protected or otherwise addressed by the design. This keeps the system practical in typical ceiling configurations while ensuring larger cavities don’t create excessive fire growth risk before sprinklers respond.

In NFPA 13R for low-rise residential systems, there is an exemption that allows small unprotected ceiling pockets to be left without sprinklers. The limit for this exemption is 12 inches. That means pockets up to 12 inches deep can be exempt from protection, while pockets deeper than 12 inches must be protected or otherwise addressed by the design. This keeps the system practical in typical ceiling configurations while ensuring larger cavities don’t create excessive fire growth risk before sprinklers respond.