sprinklernotes
Area Limitations for Standpipe Systems You have asked the following question: “The state fire marshal is asking us to add an additional system riser in the fire pump room due to the first floor being 54,000 sq. ft. Our current arrangement consists of one 6 in. feed main coming out of the pump room and feeding four vertical standpipes in the stairwells with two zone control assemblies feeding approximately half of the building each. We are identifying the zone assemblies as our system risers, not the feed main coming from the pump room. Would we need to split the standpipe system into areas less than 52,000 sq. ft. by splitting up the standpipe feed main into two separate mains in the pump room?” In response to your question, we have reviewed NFPA 14, 2016 edition as the applicable standard. Our informal interpretation is the single feed main is an acceptable arrangement.
Typically, the system size for standpipes is only limited by the building’s footprint. NFPA 14 places no limits to a supply pipe supplying standpipe system unless the standpipe systems is dry automatic or semi-automatic where the volume controlled by one dry pipe valve cannot exceed 750 gallons per Section 5.2.1.2.1. Now, Sections 7.10.1.1.3 and 7.10.1.1.3.1 will require adding demand per each standpipe to the calculations depending on whether the floor area of the building does or does not exceed 80,000 sq. ft. With that being said, nowhere does it require additional supply or feed mains for the standpipe system to be broken into areas smaller than 52,000 sq. ft. The area limitation of 52,000 sq. ft. comes is from NFPA 13 and is a requirement for sprinkler systems only.
