sprinklernotes Floor Control Valve Assemblies “We are finishing up a project that involves a basement and two levels above grade. The basement system has a control valve assembly and first/second floor system has a combined control valve assembly. Have we met the intent of section 8.2.4.1?”
We have reviewed NFPA 13, Standard for the Installation of Sprinkler Systems, 2016 edition as the applicable standard as well as the International Building Code (IBC), 2015 edition. Our informal interpretation is that this application meets the intent of the standard. The base requirement for floor control valve assemblies per section 8.2.4.1 is for multi-story buildings exceeding two stories in height. The annex clarifies it is not the intent of this section to require floor control valve assemblies in all multi-story buildings. Where small buildings such as multi-level condominiums or apartments are under the control of a single owner or management firm, a single control valve should be adequate for isolation, control, and annunciation of water flow. With that said, the intent of this application is concerned with “height” where that is typically viewed as above grade. This application would be considered two stories. The NFPA 13 standard does not address definitions of story or height (except for storage). Where one can turn to is the building code or IBC as a reference. A story is defined as that portion of a building included between the upper surface of a floor and the upper surface of the floor or roof next above (see “Basement,” “Building height,” “Grade plane” and “Mezzanine”). A story is measured as the vertical distance from top to top of two successive tiers of beams or finished floor surfaces and, for the topmost story, from the top of the floor finish to the top of the ceiling joists or, where there is not a ceiling, to the top of the roof rafters. The commentary from the IBC Handbook clarifies that all levels in a building that conform to this description are stories, including basements. As such, the basement in this application would be a story. Height in the IBC is defined (Height, Building) as the vertical distance from grade plane to the average height of the highest roof surface. In that definition, the building would be considered two stories. The code definitions create an ambiguity between stories and height in the application of 8.4.2.1 of NFPA 13. This issue has been flagged for the committee to address for the next cycle of NFPA 13. The AHJ may elect to ignore the height component as part of the criteria and rule that this is a three-story building (basement, first, and second floor) where the floor control valve assemblies would be required for each level. The exceptions are section 8.2.4.2 where the floor control valve, check valve, main drain valve, and flow switch required by section 8.2.4.1 shall not be required where sprinklers on the top level of a multi-story building are supplied by piping on the floor below. As such, you meet this exception by providing floor control valve assemblies in the basement and ground floor, and the ground floor supplies the top level of the building. Next is section 8.2.4.3 where the floor control valve, check valve, main drain valve, and flow switch required by section 8.2.4.1 shall not be required where the total area of all floors combined does not exceed the system protection area limitations of section 8.2.1. The limit for light and ordinary hazard occupancies is 52,000 sq. ft. If the total area of all floors combined does not exceed 52,000 sq. ft., floor control valve assemblies are not required for each story. Your installation not only complies with the primary requirement since it has a height of only two stories, but also meets exceptions to the base requirement. Your application has met the intent of the standard when applying section 8.2.4.
