Kidde Fire Systems DS Series, Application Manual

Page: 22 / 42

K-76-1000 -20- July 2016
Sloping Ceilings with Beams
For sloping ceilings with beams running parallel up the slope:
•
Locate the smoke detectors on the ceiling within the beam pockets.
• The ceiling height is the average height over slope.
• To determine the detector spacing, measure along the horizontal projection of the ceiling.
• Smooth ceiling spacing is permitted within beam pocket(s) parallel to the beams.
• For beam depths less than or equal to 10 percent of the ceiling height (0.1 H), locate the detectors
with smooth ceiling spacing perpendicular to the beams.
• For beam depths greater than 10 percent of the ceiling height (0.1 H) and beam spacing greater than
or equal to 40 percent of the ceiling height (0.4 H), locate the detectors in each beam pocket.
• For beam depths greater than 10 percent of the ceiling height (0.1 H) and beam spacing less than 40
percent of the ceiling height (0.4 H), smoke detectors are not required in every beam pocket but must
be spaced not greater than 50 percent of smooth ceiling spacing.
Sloping Ceilings with Intersecting Beams
For sloped ceilings with beam pockets formed by intersecting beams, position the detectors on the bottom
of perpendicular beams and align them with the center of the pocket. See Figure 12.
Figure 12. Spacing for Sloping Ceilings with Beam Pockets Formed by Intersecting Beams
Smoke detector
D = Beam depth
H = Average ceiling height over slope
1. Upslope
2. Place the detectors with not more than three beams between detectors and not exceeding
the smooth ceiling spacing
3. Place the detectors with not more than two beams between detectors and not exceeding the
50-percent of the smooth ceiling spacing
D/H 0.1 D/H 0.1
1
2 3