Rendering something (structures, materials, etc.) resistant to fire, or incombustible
Spray
gypsum
-based
plaster
fireproofing being installed.
Circuit integrity
fireproofing of
cable trays
, using
calcium silicate
boards.
Damaged spray fireproofing
Fireproofing
is rendering something (
structures
, materials, etc.) resistant to fire, or incombustible; or material for use in making anything fire-proof.
[1]
It is a
passive fire protection
measure. "Fireproof" or "fireproofing" can be used as a noun, verb or adjective; it may be hyphenated ("fire-proof").
Applying a
certification listed
fireproofing system to certain structures allows them to have a
fire-resistance rating
. The term "fireproofing" may be used in conjunction with standards, as reflected in common North American construction specifications. An item classed as fireproof is resistant in specified circumstances, and may burn or be rendered inoperable by fire exceeding the intensity or duration that it is designed to withstand.
Markets
[
edit
]
Applications
[
edit
]
- Structural steel
to keep below critical temperature ca. 540 °C
- Electrical circuits to
keep critical electrical circuits below 140 °C
so they stay operational
- Liquified petroleum gas
containers to prevent a
BLEVE
(boiling liquid expanding vapour explosion)
- Vessel skirts and pipe bridges in an
oil refinery
or
chemical plant
to keep the
structural steel
below critical temperature ca. 540°
- Concrete
linings of traffic tunnels
- Fireblocking: In a wood frame construction, gaps are created by joists or studs in floor or wall partitions. These hollow spaces allow fire to travel easily from one area to another. Fireblocks are installed internally to divide these areas into smaller intervals. Common materials used include solid lumber,
plywood
, OSB,
Particle board
,
gypsum board
, cement fiberboard, or glass fiber insulation batts.
[2]
- Firewall (construction)
is a common method employed to separate a building into small units to restrict or delay the spread of fire from one section to the next. Fire walls usually extend the full length of a building, from foundation to roof.
[3]
- Fire barriers and fire partitions: They are similar to fire walls in operation; however, their height is limited to a single floor, from the slab of one floor to the underside of the next.
[4]
- Coatings
, e.g. to fireproof wood.
[5]
[6]
History
[
edit
]
Asbestos
was one material historically used for fireproofing, either on its own, or together with binders such as
cement
, either in sprayed form or in pressed sheets, or as additives to a variety of materials and products, including
fabrics
for
protective clothing
and building materials. Because the material was later proven to cause cancer, a large removal-and-replacement industry has been established.
Endothermic
materials have also been used to a large extent and are still in use today, such as
gypsum
,
concrete
and other cementitious products. More highly evolved versions of these are used in
aerodynamics
,
intercontinental ballistic missiles
(ICBMs) and re-entry vehicles, such as the
Space Shuttles
.
Fireproofing of structural steel
[
edit
]
In a building fire,
structural steel
loses strength as the temperature increases. In order to maintain the structural integrity of the steel frame, several fireproofing measurements are taken:
- restrictions on the amount of exposed steel set by
building codes
.
[7]
- encasing structural steel in
brick
masonry or
concrete
to delay exposure to high temperatures.
[7]
Historically, these masonry encasement methods use large amounts of heavy materials, thus greatly increasing the load to the steel frame. Newer materials and methods have been developed to resolve this issue. The following lists both older and newer methods of fireproofing steel beams (
i-beams
):
[7]
- complete encasement in concrete square column.
[8]
- wrapping the i-beam in a thin layer of metal lath and then covering it with gypsum plaster. This method is effective because gypsum plaster contains water crystals that are heat resistant.
[8]
- applying multiple layers of
gypsum board
around the i-beam.
[8]
- applying spray-on fireproofing around the i-beam. Also called spray-applied fire-resistive materials (SFRM) using air pressured spray gun, which can be made from gypsum plaster, mineral fibers mixed with inorganic binder or a cementitious formula using magnesium oxychloride cement.
[8]
- enclosing the i-beam in sheet metal and fill with loose insulation.
[8]
- hollow columns filled with liquid water or
antifreeze
. When part of the column is exposed to fire, the heat is dissipated throughout by the convection property of the liquid.
[8]
- encasing the i-beam in rigid concrete slab.
[8]
- a layer of suspended plaster ceiling isolating the i-beam
[8]
Alternative methods
[
edit
]
Intumescent
spray fireproofing product has expanded.
Among the conventional materials, purpose-designed spray fireproofing
plasters
have become abundantly available the world over. The inorganic methods include:
- Gypsum
plasters
- Cementitious plasters
- Fibrous plasters
Gypsum plasters include chemical additives to create bubbles that displace solids, thus reducing the bulk density. Lightweight
polystyrene
beads may be mixed into the plasters at the factory in an effort to reduce the density, which generally results in a more effective insulation at a lower cost. The resulting plaster has qualified to the A2
[
clarification needed
]
combustibility rating as per DIN4102.
[
full citation needed
]
Fibrous plasters, containing either
mineral wool
, or
ceramic
fibres tend to simply entrain more air, thus displacing the heavy fibres.
Proprietary boards and sheets, made of
gypsum
,
calcium silicate
,
vermiculite
,
perlite
, mechanically-bonded composite boards made of punched sheet-metal and cellulose-reinforced concrete have all been used to clad items for increased fire resistance.
An alternative method to keep building steel temperature below the critical strength limit is to use
liquid convection cooling
in hollow structural members.
[9]
This method was patented in the 19th century although the first prominent example was 89 years later.
[10]
Traffic tunnels
[
edit
]
Traffic tunnels may be traversed by vehicles carrying flammable goods, such as petrol,
liquefied petroleum gas
and other
hydrocarbons
, which are known to cause a very rapid temperature rise and high ultimate temperatures in case of a fire (see the hydrocarbon curves in
fire-resistance rating
). Where hydrocarbon transports are permitted in tunnel construction and operations, accidental fires may occur, resulting in the need for fireproofing of traffic tunnels with concrete linings.
Concrete exposed to hydrocarbon fires
[
edit
]
Concrete
cannot, by itself, withstand severe hydrocarbon fires. In the
Channel Tunnel
that connects the
United Kingdom
and
France
, an intense fire broke out and reduced the concrete lining in the undersea tunnel down to about 50 mm.
[
citation needed
]
In ordinary building fires, concrete typically achieves excellent fire-resistance ratings, unless it is too wet, which can cause it to crack and explode. For unprotected concrete, the sudden
endothermic
reaction of the
hydrates
and unbound humidity inside the concrete generates pressure high enough to
spall
off the concrete, which falls in small pieces on the floor of the tunnel. Humidity probes are inserted into all concrete slabs that undergo fire testing to test for this, even for the less severe building elements curve (DIN4102, ASTM E119, BS476, or ULC-S101). The need for fireproofing was demonstrated, among other
fire protection
measures, in the European "Eureka" Fire Tunnel Research Project, which gave rise to building codes for the trade to avoid the effects of such fires upon traffic tunnels. Cementitious spray fireproofing must be certification-listed
and applied in the field as per that listing
, using a hydrocarbon fire test curve such as the one used in UL1709.
[11]
Fireproof vaults
[
edit
]
Fireproof vaults to protect important paper documents are usually built using concrete or masonry blocks as the primary building material.
[
citation needed
]
In the event of a fire, the chemically-bound water within the concrete or masonry blocks is forced into the vault chamber as steam, which soaks the paper documents to keep them from igniting.
[
citation needed
]
This steam also helps keep the temperature inside the vault chamber below the critical 176.7 °C (350 °F) threshold, which is the point at which information on paper documents is destroyed.
[
citation needed
]
The paper can later be remediated with a freeze drying process if the fire is extinguished before internal temperatures exceed 176.7 °C (350 °F).
[
citation needed
]
An alternate less expensive and time-consuming construction method is using dry insulating material.
[
citation needed
]
This vault construction method is sufficient for paper documents, but the steam generated by concrete and masonry structures will destroy contents that are more sensitive to heat and moisture. For example, information on
microfilm
is destroyed at 65.5 °C (149.9 °F) (a.k.a. Class 150)
[
citation needed
]
and magnetic media (such as data tapes) lose data above 51.7 °C (125.1 °F) (a.k.a. Class 125).
[
citation needed
]
Fireproof vaults built to meet the more stringent Class 125 requirement are called data-rated vaults.
[
citation needed
]
All components of fireproof vaults must meet the fire protection rating of the vault itself, including doors, HVAC penetrations and cable penetrations.
[12]
See also
[
edit
]
References
[
edit
]
- ^
Oxford English Dictionary 2nd ed
- ^
Allen 2009, p. 885
- ^
Allen, Edward; Iano, Joseph (2009).
Fundamentals of building construction : materials and methods
. Iano, Joseph. (5th ed.). Hoboken, N.J.: Wiley. p. 884.
ISBN
9780470074688
.
OCLC
209788024
.
- ^
Allen 2009, p. 878
- ^
Paleja, Ameya (22 August 2022).
"A fireproof wood achieves the highest class in burning test thanks to an invisible coating"
.
interestingengineering.com
. Retrieved
18 September
2022
.
- ^
"An invisible coating to make wood 'fireproof'
"
.
Nanyang Technological University
via techxplore.com
. Retrieved
18 September
2022
.
- ^
a
b
c
Allen 2009, p. 459
- ^
a
b
c
d
e
f
g
h
Allen 2009, p. 460 - 463
- ^
Fisher, Arthur (May 1970).
Water-Filled Columns Keep Building Frames Cool in Fires
. Popular Science
. Retrieved
27 Jan
2012
.
- ^
see
U.S. Steel Tower
- ^
"Scope for UL 1709"
.
ulstandardsinfonet.ul.com
. Archived from
the original
on 2001-03-29.
- ^
National Fire Protection Association 232 "Protection of Records"
External links
[
edit
]
|
---|
Fundamental concepts
| | |
---|
Technology
| |
---|
Building design
| |
---|
Fire alarm systems
| |
---|
Professions, trades,
and services
| |
---|
Industry organizations
| |
---|
Standards
| |
---|
Awards
| |
---|
See also
| |
---|
|
|
---|
Fundamental
concepts
| |
---|
Technology
| |
---|
Components
| |
---|
Measurement
and control
| |
---|
Professions,
trades,
and services
| |
---|
Industry
organizations
| |
---|
Health and safety
| |
---|
See also
| |
---|