sprinklernotes
Light Fixtures and Residential Sprinklers
You have asked the following question: “I have light hazard occupancy
(residential unit) being protected with residential sprinklers. There is a
light fixture located approximately 2 ft from a sprinkler. Would the sprinkler
need to be relocated to be at least 36 in. away from the center of the light
NFPA 13, 2010 edition Section 8.10.6.2.1.3 or do we only consider structural
members per Section 8.6.5.2.1.4?” In response to your question, we have
reviewed NFPA 13, 2010 edition as the applicable standard. Our informal
interpretation is the sprinkler has to be positioned a minimum distance of four
times the maximum dimension of the light fixture away from the fixture.
In light and ordinary hazard occupancies, Section 8.6.5.2.1.4 requires
sprinklers to be positioned away from structural members by a minimum distance
of three times the maximum dimension of the structural member when using
standard spray sprinklers. However, this is a residential project utilizing
residential sprinklers, thus the “three times rule” of Section 8.6.5.2.1.3 is
not applicable. Similar to the “three times rule” for standard spray sprinklers
there is the “four times rule” of Section 8.10.6.2.1.3 for residential
sprinklers. Section 8.10.6.2.1.3 states:
Unless the requirements of 8.10.6.2.1.4 through 8.10.6.2.1.8 are met,
sprinklers shall be positioned away from obstructions a minimum distance of
four times the maximum dimension of the obstruction (e.g., truss webs and
chords, pipe, columns, and fixtures). The maximum clear distance required shall
be 36 in. (914 mm) in accordance with Figure 8.10.6.2.1.3.
However, there is not a similar allowance to ignore all obstructions except for
structural members for residential sprinklers. With this being the case, the
sprinkler has to be positioned a minimum distance of four times the maximum
dimension of the light fixture away from the light fixture up to a maximum of
36 in.
