Fire Flow Calc in NFPA 1 versus NFPA 1142

[CivilizedPE]

I'm working on project in a rural area of NY that has a municipal water supply. I need to determine the needed fire flow to the site and think I can use NPFA 1 to do this. Some suggested using NFPA 1142, but that is for rural or suburban areas where an adequate water supply doesn't exist. Since we are connecting to a municipal system that happens to have an elevated tank, I didn't think it applied. However, we have calculations based on both codes and are comparing the two. Our AHJ simply says to meet NFPA, but doesn't specify a section. FYI, our buildings are sprinklered so we are applying the 75% credit allowed by NFPA 1, Chapter 18. Even with the 75% credit the fire flow is greater than the sprinkler demands, so that governs the supply volume.

Does anyone know why NFPA 1 Table 18.4.5.1.2 omits occupancy and only considers construction type, while the minimum water supply calculation in NFPA 1142 4.3.1 uses both occupancy and construction type? Any suggestions for minimizing the required volume of storage? We are already accounting for fire separations in the buildings and counting them as separate buildings. Thanks for the input.

 

[stookeyfpe]

NY state adopts the ICC International Fire Code Appendix B, which takes precedence because it has the force of law.

 

[CivilizedPE]

Thanks stookeyfpe. Could you point me to a code or law that states that NY state has adopted Appendix B of the IFC. FYI, the table in App B of the IFC is essentially the same as NFPA 1, but the commentary in IFC was very interesting.

 

[cdafd]

Not sure if it is adopted

http://publicecodes.cyberregs.com/st/ny/st/b300v10/index.htm

 

[CivilizedPE]

Thanks cdafd. I dug a little more into the link you sent for the NYS Fire Code and found the following in Chapter 1, Section 102 Applicability .

102.6 Appendices. The following appendices have been adopted and are made part of this code:
Appendix D-Fire Apparatus Access Roads

It does not mention Appendix B - Fire-flow Requirements for Buildings

The NYS Fire Code states:
§F508.3 Fire flow. Fire flow requirements for buildings or portions of buildings and facilities shall be determined by an approved method.

What is this "approved menthod"? NFPA 1? IFC Appendix B? ISO?

This question regarding the "approved method" is what led us to examine both NFPA 1 and NFPA 1142 in the first place.

This is really good dialogue, so I invite others to comment especially if they have worked on fire flow in NYS.

Thanks!

 

[stookeyfpe]

The approvied method is whatever they dictate by policy. I know that's not the answer you're looking for but its up to the jurisdiction. Dan Nichols, P.E., is their fire protection engineer. I would try a phone call to the Office of Fire Prevention and Control and see if you can contact him.