• The closed door may prevent an alarm not located in that room
from waking the sleeper.
• Smoke, heat, and combustion products rise to the ceiling and
spread horizontally. Mounting the smoke alarm on the ceiling in
the center of the room places it closest to all points in the room.
Ceiling mounting is preferred in ordinary residential
construction.
• For mobile home installation, select locations carefully to avoid
thermal barriers that may form at the ceiling. For more details, see
MOBILE HOME INSTALLATION below.
• When mounting an alarm on the ceiling, locate it at a minimum of
4” (10 cm) from the side wall (see figure 1).
• When mounting the alarm on the wall, use an inside wall with
the top edge of the alarm at a minimum of 4” (10 cm) and a
maximum of 12” (30.5 cm) below the ceiling (see figure 1).
• Put smoke alarms at both ends of a bedroom hallway or large
room if the hallway or room is more than 30 feet (9.1 m) long.
NOT
IN THIS
AREA
(10 cm)
4"
MINIMUM
(10 cm)
4"
CEILING
DEAD AIR
SPACE
SIDE
WALL
MINIMUM
(30.5 cm)
12"
MAXIMUM
BEST
HERE
NEVER
HERE
ACCEPTABLE
HERE
FIGURE 2
FIGURE 3
FIGURE 1
(0.9 m)
3'
(102 mm)
4"
NOT
IN THIS
AREA
ANYWHERE
IN THIS AREA
(0.9 m)
3'
(0.9 m)
3'
(102 mm)
4"
NOT
IN THIS
AREA
ANYWHERE
IN THIS
AREA
ANYWHERE ALONG
THIS BOLD SURFACE
30.5 cm
Locations permitted for smoke
alarms and smoke detectors
on tray-shaped ceilings.
0920-7201-00_EN_V10.qxd:_ 2017.4.27 10:02 AM Page 3
