• When mounting an alarm on the ceiling, locate it at a minimum
of 4” (10cm) 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” (10cm) and a
maximum of 12” (30.5cm) 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 ft (9.1 m) long.
• Install Smoke Alarms on sloped, peaked or cathedral ceilings at
or within 3ft (0.9m) of the highest point (measured horizontally).
NFPA 72 states: “Smoke alarms in rooms with ceiling slopes
greater than 1 ft in 8 ft (.3m in 2.4m) horizontally shall be locat-
ed on the high side of the room.” NFPA 72 states: “A row of
alarms shall be spaced and located within 3 ft (0.9m) of the
peak of the ceiling measured horizontally” (see figure 3).
2. LOCATIONS TO AVOID
In general alarms should not be located:
• In the garage. Products of combustion are present when you
start your automobile.
• Less than 4” (10cm) from the peak of an “A” frame type ceiling.
• In an area where the temperature may fall below 40ºF or rise
above 100ºF, such as garages and unfinished attics.
• In dusty areas. Dust particles may cause nuisance alarm or fail-
ure to alarm.
FIGURE 1
FIGURE 2
FIGURE 3