Figures 2, 3, 4 & 5 are reprinted with permission from NFPA 72, National Fire Alarm Code®,
Copyright ©2010, National Fire Protection Association, Quincy, MA 02169. This reprinted
material is not the complete and official position of the National Fire Protection Association on the
referenced subject which is represented only by the standard in its entirety.
National Fire Alarm Code® and NFPA 72® are registered trademarks of the
National Fire Protection Association, Inc., Quincy, MA 02169.
550-0158
Pg. HD-3
FIGURE 4: IN DWELLING UNITS WITH MORE THAN ONE SLEEPING
AREA, A SMOKE ALARM MUST BE PROVIDED TO PROTECT EACH
SLEEPING AREA IN ADDITION TO SMOKE ALARMS REQUIRED IN
BEDROOMS.
In addition to smoke alarms outside of the sleeping areas and in each
bedroom, NFPA 72 requires the installation of a smoke alarm on each
additional level of the dwelling unit, including the basement. These
installations are shown in FIGURE 5. The living area smoke alarm should be
installed in the living room or near the stairway to the upper lever, or in both
locations. The basement smoke alarm should be installed in close proximity to
the stairway leading to the floor above. Where installed on an open-joisted
ceiling, the smoke alarm should be placed on the bottom of the joists. The
smoke alarm should be positioned relative to the stairway so as to intercept
smoke coming from a fire in the basement before the smoke enters the
stairway.
Figure 3
Figure 3: A SMOKE ALARM MUST BE LOCATED BETWEEN THE
SLEEPING AREA AND THE REST OF THE DWELLING UNIT AS WELL AS IN
EACH BEDROOM.
In dwelling units with more than one bedroom area or with bedrooms on
more than one floor, more than one smoke alarm is required, as shown in
FIGURE 4.
FIGURE 2: A SMOKE ALARM MUST BE LOCATED ON EVERY LEVEL OF
DWELLING UNIT, INCLUDING BASEMENT, WITHIN EACH SLEEPING
ROOM AND OUTSIDE SLEEPING AREAS.
Where to Locate the Required Smoke Alarms
. The major threat from fire in
a dwelling unit occurs at night when everyone is asleep. Persons in sleeping
areas can be threatened by fires in the remainder of the unit; therefore, smoke
alarms are best located in each bedroom and between the bedroom areas and
the rest of the unit as shown in FIGURE 3.
FIGURE 2
FIGURE 3
FIGURE 4
heat alarms, as shown in FIGURE 1, and the distance to the wall is reduced to
12 ½ ft. (3.8 m). Since ½ x 50 ft. (15 m) is 25 ft. (7.6 m), the distance between
alarms across open wood joists should not exceed 25 ft. (7.6 m), as shown in
FIGURE 1, and the distance to the wall is reduced [ ½ x 25 ft. (7.6 m)] to 12.5
ft. (3.8 m). The alarms are required to be mounted on the bottom of the joists
and not up in joist channels.
Walls, partitions, doorways, ceiling beams and open joists interrupt the
normal flow of heat, thus creating new areas to be protected.
FIGURE 1
PLACEMENT OF HEAT ALARMS
THIS EQUIPMENT SHOULD BE INSTALLED IN ACCORDANCE WITH
THE NATIONAL FIRE PROTECTION ASSOCIATION'S STANDARD 72
(National Fire Protection Association, Batterymarch Park, Quincy, MA 02269).
For your information, the National Fire Protection Association's Standard
72, reads as follows:
NFPA 72, 2010 Edition, Chapter 29, Section 29.5.1.1 Where required by
applicable laws, codes or standards for a specific type of occupancy, approved
single and multiple-station smoke alarms shall be installed as follows:
29.5.1.1
Where required by applicable laws, codes or standards for a specific
type of occupancy, approved single and multiple-station smoke alarms shall be
installed as follows:
1) In all sleeping rooms and guest rooms
2) Outside of each separate dwelling unit sleeping area, within 6.4m (21ft) of
any door to a sleeping room, the distance measured along a path of travel
3) On every level of a dwelling unit, including basements
4) On every level of a residential board and care occupancy (small
facility),including basements and excluding crawl spaces and unfinished
attics
5) In the living area(s) of a guest suite
6) In the living area(s) of a residential board and care occupancy (small facility)
29.5.1.2
Where the area addressed in 29.5.1.1(2) is separated from the
adjacent living areas by a door, a smoke alarm shall be installed in the area
between the door and the sleeping room, and additional alarms shall be
installed on the living area side of the door as specified by 29.5.1.1 and
29.5.1.3.
29.5.1.3
In addition to the requirements of 29.5.1.1(1) through 29.5.1.1(3),
where the interior floor area for a given level of a dwelling unit, excluding
garage areas, is greater than 93m
2
(1000ft
2
), smoke alarms shall be installed
per 29.5.1.3.1 and 29.5.1.3.2.
29.5.1.3.1
All points on the ceiling shall have a smoke alarm within a distance
of 9.1m (30ft) travel distance or shall have an equivalent of one smoke alarm
per 46.5m
2
(500ft
2
) is evaluated by dividing the total interior square footage of
floor area per level by 46.5m
2
(500ft
2
).
29.5.1.3.2
Where dwelling units include great rooms or vaulted/cathedral ceil-
ings extending over multiple floors, smoke alarms located on the upper floor
that are intended to protect the aforementioned area shall be permitted to be
considered as part of the lower floor(s) protection scheme used to meet the
requirements of 29.5.1.3.1.
The installation of additional alarms of either the smoke, heat or CO type
should result in a higher degree of protection. Adding alarms to rooms that are
normally closed off from the required alarms increases the escape time
because the fire does not need to build to the higher level necessary to force
smoke out of the closed room to the required alarms. As a consequence, it is
recommended that the householder consider the installation of additional fire
protection devices.
However, it should be understood that NFPA 72 does not require additional
smoke alarms over and above those called for in FIGURES 2, 3, 4 and 5
where required smoke alarms are shown.
