sprinklernotes
Residential Sidewalls and Soffits
You asked the following questions: “Section 8.7.4.1.3.3 of NFPA 13, 2016 edition allows standard sidewall sprinklers to be installed under a soffit when both the minimum distance from the sprinkler deflector to the bottom of the soffit and maximum distance from the sprinkler deflector to the high ceiling is maintained. There is no applicable section or provision in NFPA 13, 2016 edition for residential sidewall sprinklers. Are residential sidewall sprinklers permitted to be installed under a soffit if both the minimum distance from the sprinkler deflector to the bottom of the soffit and maximum distance from the sprinkler deflector to the high ceiling is maintained?” We have reviewed NFPA 13, 2016 edition that you indicated as the applicable standard. Our informal interpretation is that the soffit requirement for sidewall spray sprinklers should also apply to residential sprinklers. Although the allowance for a sidewall sprinkler to be installed beneath a soffit is identified only in section 8.7, this does not mean that the underlying reasons for its allowance applies only to spray sprinklers. This just means that the public input was submitted on section 8.7 and the committee did not consider its broader application. This is a common consequence of having to process such a large number of public inputs. The basic evaluation for this issue as identified in section 8.1.1(3) is whether there is satisfactory performance with respect to activation time and distribution. Considering that the thermal link is the same for both sprinklers, the activation will effectively be the same. The committee obviously considered the impact on activation time to be negligible. Considering that the soffit is not in the path of the water discharge, the performance regarding discharge is unaffected. As such, there is no logical reason not to extend the same criteria to residential sidewall sprinklers. Since this is not explicitly identified in NFPA 13, concurrence by the AHJ is required.
