FM Global Property Loss Prevention Data Sheets: List of Figures
FM Global Property Loss Prevention Data Sheets: List of Figures
FM Global Property Loss Prevention Data Sheets: List of Figures
HIGH-RISE BUILDINGS
Table of Contents
Page
List of Figures
Fig. 1A.
Typical exterior window arrangement ............................................................................................... 3
Fig. 1B.
Window heights ................................................................................................................................ 3
Fig. 2A.
Exterior wall glass in metal frame. Firestopping friction fit in space and supported by clip angle. . 4
Fig. 2B.
Firesafing friction fit into space and held in place by clip angle secured to exterior precast
concrete panel .................................................................................................................................. 4
Fig. 2C. Firesafing support welded in place .................................................................................................. 5
Fig. 2D. Continuous glass exterior ................................................................................................................. 6
Fig. 3. Leaning high-rise buildings ................................................................................................................. 7
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1-3 High-Rise Buildings
Page 2 FM Global Property Loss Prevention Data Sheets
1.0 SCOPE
This data sheet provides recommendations concerning the unique hazards associated with high-rise
buildings.
1.1 Changes
May 2008. A reference to Data Sheet 5-23, Emergency and Standby Power Systems, was added. An editorial
review was completed.
2.1.3 Protect openings between floors found in shafts, chases and stairwells, or openings in partitions
between floor areas, should be protected with FM Approved (see Appendix A for definition) and labeled fire
doors. Ensure these are normally closed or are automatic closing fire doors having a fire rating of at least
1-1⁄2 hours (unless otherwise noted) and installed in accordance with Data Sheet 1-23, Protection of Openings
in Fire Subdivisions.
2.1.4 Have openings in floor slabs used for utilities (poke-throughs) protected with FM Approved floor
penetration fire stops with a 2-hour fire resistance rating.
2.1.5 Ensure panels used for exterior walls are noncombustible. Examples include concrete, masonry, or
glass fiber insulated steel sandwich panels. Ensure the panels and frames are tightly secured at each floor
(to prevent outward buckling under fire exposure), with the space between the panels and the floor slabs
filled with a noncombustible firesafing (fire-stopping) material, such as mineral wool or ceramic fiber, which
has passed a fire-resistance test conducted by a recognized testing lab for a minimum of two hours. Because
floor dimensions are usually limited in a high-rise building, internal expansion joints between floor sections are
rarely provided. If such a situation is encountered, however, provide protection as described above.
Do not use glass fiber as firesafing. Ensure the firesafing is securely held in place. Z clips may be used to
support (or to pierce) the underside of the firesafing and hold it in place. (See Figures 2a to 2c for appropriate
designs.)
Fig. 2A. Exterior wall glass in metal frame. Firestopping friction fit in space and supported by clip angle.
Fig. 2B. Firesafing friction fit into space and held in place by clip angle secured to exterior precast concrete panel
Glass exterior cladding also may be used as long as interior cladding, such as steel panels or gypsum board,
limit the window height to within the range noted in Recommendation No. 2.1.2 above.
When glass exterior cladding is used, spandrel heights must be defined by interior cladding, such as steel
panels or gypsum board.
The location of the horizontal joint between vertical sections of glass panels also is critical. If a vertical section
of glass panel spans from floor to floor with horizontal joint in line with the floor, assume glass will shatter
on the fire floor and the floor above, and analyze exterior fire spread potential the same as for openable
windows (H ≥ 3.8 h).
If the horizontal joint between vertical sections of glass panels occurs at the top of the spandrel immediately
above the assumed fire floor (see Fig. 2d) and the window sill is steel, assume the glass on the fire floor
will shatter, but the next glass panel above will remain intact and seal off the window opening on the floor
above the fire if the window ratio is H ≥ 2.8 h.
Ensure sandwich panel curtain walls using aluminum skins, combustible insulation (such as foam plastic)
or no insulation are completely interrupted at each floor with a barrier of equal fire resistance to that of the
floor.
2.1.6 Separate atriums and other open areas that extend between multiple floors from adjacent occupied
areas with a smoke-tight fire partition having a fire-resistance rating of at least two hours. Protect openings
with FM Approved and labeled fire door (normally closed or automatically operated by smoke detection) with
a minimum 1-1⁄2 hour fire rating. If windows are provided in the fire partition, ensure they have a minimum 1-1⁄2
hour fire rating.
2.1.7 Arrange protection against d earthquake in accordance with Data Sheet 1-2, Earthquakes; Data Sheet
1-28, Wind Design; Data Sheet 1-29, Roof Deck Securement and Above-Deck Roof Components; Data Sheet
1-49, Perimeter Flashing; and the Approval Guide, a publication of FM Approvals.
2.1.8 Guidelines relating to vertical firespread in this data sheet do not apply to leaning high-rise buildings.
(See Fig. 3.)
2.2 Protection
2.2.1 Provide sprinkler protection for all high-rise buildings as follows:
a) Provide automatic sprinkler protection throughout all high-rise buildings.
b) Provide all atriums with sprinkler protection at the roof level as well as at each floor, under corridors
or balconies facing the atrium. If the ceiling or roof is more than 30 ft (9 m) high, keep the combustible
loading at a limited level.
2.2.2 Install sprinklers in accordance with Data Sheet 2-8N, Installation of Sprinkler Systems (NFPA), and
Data Sheet 3-26, Fire Protection Water Demand for Nonstorage Sprinklered Properties.
2.2.3 Provide an adequate water supply for fire protection according to Data Sheet 3-26, Data Sheet
3-7N/13-4N, Centrifugal Fire Pumps (NFPA); and Data Sheet 2-8N, Installation of Sprinkler Systems (NFPA).
Ensure pressure does not exceed 175 psi (1206 kPa) (12.1 bar) on sprinkler piping, sprinklers and backflow
preventers.
2.2.4 Whenever possible, design water supply and fire protection systems to avoid the need for pressure-
regulating valves. When unavoidable, install FM Approved pressure-regulating valves in accordance with
Data Sheet 3-11, Pressure-Reducing Valves for Fire Protection Service.
2.2.5 Provide standpipes for Class III service with both 2-1⁄2 in. (64 mm) and 1-1⁄2 in. (38 mm) hose
connections in accordance with Data Sheet 4-4N, Standpipe and Hose Systems (NFPA). Ensure the water
supply is able to provide a total demand of 500 gal/min (1890 L/min) plus 250 gal/min (945 L/min) for each
additional standpipe at an adequate pressure at the topmost outlet. Contact the fire service to determine
needed water pressure, taking into consideration the operating pressure for the particular nozzles used and
friction loss through the hose. The sprinkler and hose demand outlined in Recommendation No. 2.2.2 need
not be added to these demands, but should be available as recommended.
2.2.6 Install grouped electrical cables according to the National Electrical Code and Data Sheet 5-31/14-5,
Cables and Bus Bars.
2.2.7 Provide a supervised fire alarm system connected to a constantly attended location. Have the alarm
system monitor waterflow alarms for each sprinklered floor, all smoke detectors, and heat detectors in
unsprinklered areas, and provide electrical supervision for fire pumps, tanks and reservoirs in accordance
with Data Sheet 9-1, Supervision of Property, and other applicable data sheets. Due to the large number of
sprinkler valves and the impact of a shut valve, also have valve tamper alarms constantly monitored.
2.2.8 Provide portable fire extinguishers in accordance with Data Sheet 4-5, Portable Extinguishers.
2.2.9 Protect ducts for air conditioning and exhaust systems in accordance with Data Sheet 1-45, Air
Conditioning and Ventilating Systems, and Data Sheet 7-78, Industrial Exhaust Systems.
2.2.10 Arrange smoke control for atriums as follows:
a) Provide an independent, mechanical smoke exhaust system at the top of the atrium for removal of
smoke that rises to this level from the base of the atrium, or from floors opening to it. Design the exhaust
system to provide at least six air changes per hour in the atrium. If the volume exceeds 600,000 ft3 (16,
800 m3), design the exhaust system to provide at least four air changes per hour. Other designs made
according to NFPA 92B may be acceptable.
b) Have the exhaust system activated by smoke detectors installed at the atrium ceiling level, in
accordance with Data Sheet 5-48, Automatic Fire Detectors, and the Approval Guide.
c) Where practical, design the air-handling systems in areas adjacent to the atrium to pressurize these
areas upon smoke detection.
2.2.11 Provide an independent air supply system to pressurize the stairwells as follows:
a) Have the air supplied through a single duct running vertically inside the stairwell.
b) Provide air injection at alternate floors to ensure air movement, and maintain pressurization.
c) Ensure the air-distribution system is continuously self-balancing, eliminating the need for extensive
adjustments following installation.
d) Arrange the stairwell pressurization system in zones comprising a maximum of 14 stories per zone.
Design the system to maintain pressurization with three doors open per zone.
e) Protect fans, power supply, and distribution system by enclosing them in construction of at least 2-hour
fire resistance.
f) If two different zones are located on the same floor, ensure they are separated from each other by
fire walls of equal fire resistance to that of the stairwell enclosure.
2.2.12 Elevator protection depends on the size and type of building. The following recommendations can
be adapted to meet a particular need.
a) Design high-rise buildings so elevator shafts are away from the areas of potential fire danger; i.e.,
on the perimeter or in an isolated core.
b) Configure elevator controls so that activation of a fire alarm in the emergency communication center
will send them directly to the first floor or lobby.
c) Ensure at least two elevators servicing each floor have the ability to be dedicated for firefighters’ use
and to be operated with special keys. Ensure these elevators are in protected shafts that have a 2-hour
fire resistance.
2.2.13 Establish an emergency communication center for the following functions, according to the size of
the building and its fire hazards:
a) The control point for emergency communication
b) The control point for emergency operation of all the building electro-mechanical systems, such as fans,
elevators, smoke control, fire protection, etc.
c) The center for directing firefighting and rescue operations
3.1.1 Fire Spreads Five Stories via Windows and Openings at the Edge of Floors
This facility was a 62-story office tower located in the business district of a large city. The building had
protected steel with floors of concrete over steel form deck. The structural frame was 3-hour fire rated, and
the stairwells, elevator enclosures and floor assemblies were 2-hour fire rated. The exterior walls were glass
curtain walls in an aluminum frame with a 3 in. (76 mm) space between the floor slab and the curtain wall filled
with fiber batt insulation. A sprinkler system was being installed at the time of the fire, but was not in service.
A fire started on the 12th floor, which was occupied by computer work stations in an open floor plan (few
interior partitions). About 1⁄2 hour after the first alarm, witnesses reported that the 12th and 13th floors were
heavily involved in the fire. About one hour into the fire, witnesses noted that the exterior windows on the
13th floor were breaking and flames propagating outside to the 14th floor. Later, the fire department reported
that fire spread to the 16th floor through the space between the floor slab and the glass curtain wall. Control
of the fire took almost four hours and the combined efforts of 64 fire companies, over 380 fire fighters, and
four helicopters.
The 12th, 13th, and 14th floors were gutted by the fire. Contents on the 15th floor were severely damaged.
Contents located at the perimeter of the 16th floor were fire damaged. Fire spread to a small room on the
27th floor via an air handling duct. However, minimal damage occurred. Water damage was reported on all
floors below the fire, and smoke damage was reported as high as the 50th floor. Minor damage was reported
to the protected steel of the structural frame, although it was reported that at least portions of the floor slabs
on the 13th, 14th, 15th, and 16th floors had to be replaced.
4.0 REFERENCES
4.1 FM Global
Data Sheet 1-2, Earthquakes
Data Sheet 1-20, Protection Against Fire Exposure
Data Sheet 1-23, Protection in Openings in Fire Subdivisions
Data Sheet 1-28, Wind Design
Data Sheet 1-29, Roof Deck Securement and Above-Deck Roof Components
Data Sheet 1-45, Air Conditioning and Ventilating Systems
Data Sheet 1-49, Perimeter Flashing
Data Sheet 2-8N, Installation of Sprinkler Systems (NFPA)
Data Sheet 3-7N/13-4N, Centrifugal Fire Pumps (NFPA)
Data Sheet 3-11, Pressure Reducing Valves for Fire Protection Service
Data Sheet 3-26, Fire Protection Water Demand for Nonstorage Sprinklered Properties
Data Sheet 4-4N, Standpipe and Hose Systems (NFPA)
Data Sheet 4-5, Portable Extinguishers
Data Sheet 5-31, Cables and Bus Bars
Data Sheet 5-48, Automatic Fire Detectors
Data Sheet 7-78, Industrial Exhaust Systems
Data Sheet 9-1, Supervision of Property
Data Sheet 5-23, Emergency and Standby Power Systems
Approval Guide, publication of FM Approvals, Building Materials Section
4.2 Other
National Fire Protection Association, NFPA 92B, Smoke Control for Atriums and Large Spaces