Fire Safety of Wood Buildings is not on Trial!
By Michael Giroux
President, Canadian Wood Council
VANCOUVER, May 18 /CNW/ - In the last few weeks, including just today in B.C., there have been many outrageous comments published in the media questioning the safety of wood frame buildings in reaction to the recent construction fire at the Richmond Remy jobsite. While we all wait for the results of the official fire investigation, I would like to set the record straight on some key facts about wood construction.
Wood is a safe, durable building material. In Canada, we've been living and working in wood-frame structures, including houses, townhouses and multi-storey apartment buildings, for a long time. According to construction statistics, more than 90 per cent of Canadian homes are built with wood.
Wood mid-rise construction was common in the early 1900s, and some of these buildings in Vancouver are still in use today.
To suggest that the outcome of the May 3rd fire at the Remy project in Richmond would have been the same if the building had been fully completed, is not plausible.
The Remy fire occurred while the building was under construction. This meant that fire safety features such as sprinklers and gypsum board protection, as well as fire doors in firewalls, all required in the completed building had not yet been installed. The firewalls in the Remy project were made of steel and two layers of one-inch-thick gypsum liner panels - with wood-frame walls to protect them from day-to-day wear, as required by the British Columbia Building Code. The use of other types of noncombustible firewalls likely would not have stopped the fire under these same circumstances.
The fire safety of a completed building involves a lot more than its structural composition. The whole system must be taken into consideration, including the building's contents and its use. Research shows that the size and severity of the majority of fires are related to the contents of a building and the living and working habits of its occupants.
Canada's National Building Code and the Provincial and Territorial regulations based upon it require that, regardless of what materials they are made of, buildings be designed to minimize risk of unacceptable loss by including fire protection features to contain a fire, limit its effect on the supporting structure, and control the spread of smoke and gases.
Wood- walls, floors and roofs must be designed to provide fire resistance ratings of up to two hours, a level of fire performance also required for other types of building materials - contributing to the time needed for occupants to escape and emergency responders to perform their duties.
Minimize Risk
For more than 50 years, the Canadian Wood Council has been at the
forefront of wood-related code issues, most notably those related to
fire. Our work has resulted in a better understanding of wood's
capabilities and its place in the Code. The Canadian Wood Council was
one of several stakeholders consulted by the provincial government
before it approved revision of the B.C. Building Code to permit
six-storey wood frame construction.
No structure can ever be completely fireproof, and all construction materials can be affected by fire as we've seen in images from the recent devastating fires in Slave Lake, Alberta. Some building materials may not burn, but they can degrade and fail when exposed to a typical building fire, which could lead to a complete structural failure.
Wood construction is an excellent choice for any residential, commercial, industrial or public building - it has a low environmental impact, is safe, durable and aesthetically appealing. Wood-frame structures are flexible and perform as well as or better than other major building materials under extreme conditions such as earthquakes. Canadian wood-frame construction technology is being adopted in both emerging and developed economies throughout the world that want the same level of comfort and safety we have enjoyed for decades.
At the Canadian Wood Council, our experts continually work with engineering professionals, fire services, local government, builders and designers to identify appropriate solutions using wood construction. You will find more information on our website www.cwc.ca.
Building and design professionals, elected local government representatives and a fire chief speak out about the Remy construction fire
"I remain committed to rebuilding our six-storey wood frame building
(Remy). Ours is not the only building to have suffered this kind of
calamity, however, the list is very small relative to the amount of
wood frame construction undertaken every year. The fact it is a
six-storey project was not a factor in the fire. I am confident in our
project and equally confident in wood as a construction material. My
company has built hundreds of units in wood without incident. Our
strong reputation for quality homes attests to the durability and value
of what we build."
-Dana Westermark, Oris Consulting (developers for Remy in Richmond)
"Wood has become an increasingly important part of our practice. It is
the only structural building material made by the sun, benefitting
nature throughout its life. We can extend those benefits by using wood
(2/3 carbon by weight) as an enduring carbon sink. Design
professionals, policy makers, contractors, developers and policy makers
need to work to ensure wood's viability in all building types and sizes
in the future."
-Peter Busby C.M., AIA, FRAIC, MAIBC, MAAA, MOAA, BCID, LEED AP, DSc
(Hon.) Managing Director, Perkins+Will Architects
"There is always a time during construction when a building is more
vulnerable to fire - this is before the fire protection measures
specified by the building code are in place and before the building is
occupied. The Remy fire wouldn't have happened if the building was
complete, as it would have been sprinklered, equipped with a fire alarm
and fire compartments and so on. As a result of this fire, additional
measures will likely be developed and enforced on construction sites to
help mitigate the risk of fire on buildings during construction. CFT
Engineering as well as the rest of the industry is presently looking
into codes, standards and construction practices used on-site so that
we can develop those measures further for buildings under
construction."
-Brad Walton, A.Sc.T.
Principal, CFT Engineering, Vancouver (fire and building code
specialists)
"Most of the concerns people have about the fire safety of taller wood
buildings come from a lack of information about how fires behave and
about how buildings are constructed to protect people and limit the
spread of fires. There's more fire protection in a mid-rise wood frame
building than in most buildings already in the community. The Remy fire
should not become a six-storey fire issue -- Remy was a construction
fire. In response, I have asked my staff to review our requirements for
fire safety plans on construction sites, which is a time of
vulnerability for buildings, to ensure all responsible precautions are
taken to prevent fires."
-Len Garis, Fire Chief, City of Surrey and Adjunct Professor in the School
of Criminology and Criminal Justice, University of the Fraser Valley
"When a wood building project is completed with all fire protection
measures in place, the building should perform as well as any building
constructed with other materials during a fire. A wood building with
fire-rated gypsum wall board and fire suppression system installed is
as safe as any building constructed with other materials - whether it's
a two-storey, four-storey or six-storey building. Also, wood frame
buildings, being much lighter than other material-type buildings, have
superior performance in an earthquake." Wood fibre is produced by
nature and has the least carbon footprint amongst all building
material. It is the only building material that one can touch and feel
its charm and warmth. I have no concern in continuing to specify wood
in future projects."
-Thomas Leung, P.Eng., Struct.Eng., MIStructE - Thomas Leung Structural
Engineering Inc., Vancouver, BC
"Although the construction fire was unfortunate the building was
unoccupied. It is important to note that none of the three redundant
fire safety features were installed - fire sprinklers, fire separations
or firewalls. Had any one of these been complete the extent of the
fire would have been significantly less."
-Andrew Harmsworth, M.Eng, P.Eng, CP, GHL Consultants Ltd., Vancouver, BC
(building code consultants and fire protection engineers)
"There is no problem with six-storey wood construction - the challenge
is fire protection of wood buildings during the construction phase when
they are vulnerable to fire. We can look at getting sprinklers in as
floors, fire walls and doors are completed at an earlier stage and
ensure there's a high level of security to protect framed buildings
from the threat of arson, which is the most common cause of fire during
construction and before occupancy."
-Casey VanDongen, President - Tri City Contracting (BC) Ltd., Kamloops,
BC (developer of the six-storey Library Square project in Kamloops, BC)
"The Remy fire was discussed by some politicians at the recent Southern
Interior Local Government Association. Wood frame construction is very
valued in our communities and I understand that it is very possible to
have added protection to wood buildings during the construction phase
which is the vulnerable stage."
-Sharon Shepherd, Mayor, City of Kelowna
"The City of Surrey will continue to promote the use of wood in our
communities - we have absolutely no concerns with wood or six-storey
wood construction. I have worked in the construction trades myself, and
I understand that these construction fires can and do happen before the
sprinklers and firewalls are in place to stop a fire. The Remy fire is
not a six-storey issue - this is an issue about preventing a fire
during the vulnerable construction phase of any construction project."
-Marvin Hunt, Councillor, City of Surrey
Wood Points
Wood Construction and Fire Safety
The Canadian Wood Council (www.cwc.ca) has assembled these key facts in response to questions about six-storey residential wood buildings permitted under the British Columbia Building Code.
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Fire is a threat to all buildings. Canada's National Building Code and
the Provincial and Territorial regulations based upon it require that,
regardless of what materials they are made of, buildings be designed to
minimize the risk of unacceptable loss by including fire protection
features to contain a fire, limit its effect on the supporting
structure, and control the spread of smoke and gases.
-
Wood walls, floors and roofs must be designed to provide fire resistance
ratings of up to two hours, a level of fire performance also required
for non-combustible building materials - contributing to the time
needed for occupants to escape and emergency responders to perform
their duties.
-
In all construction types for six-storey mid-rise buildings, openings
and doorways must be designed to provide up to 1.5 hours of fire
protection and limit the spread of fire and smoke into exit stairways.
-
In all construction types for six-storey mid-rise residential buildings,
automatic fire sprinkler systems must be installed throughout the
building to limit fire growth and the spread of fire and smoke.
-
The fire resistance of wood-frame walls or floors depends primarily on
the gypsum board used to shield the structural wood members from the
effects of heat. Gypsum board has a non-combustible core and, when
exposed to fire, it absorbs large amounts of heat as its water content
is released.
-
Steel is a noncombustible material but can quickly lose its strength
when exposed to the high temperatures of a fire. Similar to wood-frame
assemblies, light-frame steel assemblies must also be protected from
direct exposure to fire, usually by gypsum board, to prolong the time
before collapse occurs in a fire.
-
Newer insulated concrete form (ICF) systems use combustible foam. These
concrete form systems also need gypsum board or some other form of fire
protection to limit involvement of the foam in a fire and to retard the
spread of fire when such walls are used in multi-family residential
buildings.
-
The fire safety of a completed building must consider the whole system,
including the building contents and its use. For completed buildings,
research shows that the size and severity of the majority of fires are
related to the contents of a building and the living and working habits
of its occupants.
-
In multi-family residential buildings, close to 80 per cent of fires are
contained to the compartment of fire origin, regardless of construction
type. In the few cases when fire does spread to the entire structure,
such spread usually occurs at a time after the occupants have left the
building.
-
No structure can ever be completely fireproof, and all construction
materials can be affected by fire. Concrete and steel may not burn, but
they can degrade and fail when exposed to a typical building fire,
which could lead to a complete structural failure.
- Heavy timber resists fire very well - when heavy timber burns, a layer of char is created, which helps to maintain the strength and structural integrity of the wood inside, reducing the potential for complete collapse.
Remy Project Fire in Richmond
- The May 3, 2011, Remy fire in Richmond occurred during construction of a six-storey wood-frame building - before fire safety features such as sprinklers, gypsum board protection and fire doors were required to be in place. The firewalls in the structure were made of steel framing and two layers of one-inch-thick gypsum liner panels. Even firewalls built with concrete or concrete block likely would not have stopped the fire under these circumstances.
Earthquake Safety
-
Fire is a major hazard and risk to buildings and infrastructures after
major earthquakes. Concrete and masonry buildings historically have not
performed as well as wood buildings in earthquakes, and thus are likely
to be more prone to the loss of both active and passive fire protection
systems, such as sprinklers.
-
A 2010 study by the National Research Council noted that structure
deformation from an earthquake could damage a building's fire
protection systems, possibly resulting in a full fire load and failure
of the structure in a post-earthquake fire. In reinforced concrete and
masonry structures, cracking and spalling of the concrete cover used to
protect reinforcing steel could result in penetration of the flame and
rapid elevation of the steel temperatures.1
-
Research into recent earthquakes around the world shows that modern wood
structures are better able to resist seismic forces than other building
materials. Wood's flexibility, its high strength-to-weight ratio and
its high energy-absorption capacity and ductile behaviour make it a
safe choice.
- A unique earthquake simulation confirmed taller wood-frame buildings can be designed to perform safely in a major earthquake. Earthquake engineering researchers tested the seismic performance of a full-size, six-storey wood building on the world's largest shake table at a facility in Miki City, Japan.2
More information about wood performance and fire safety is available from the Canadian Wood Council at www.cwc.ca/DesignWithWood/FireSafety/?Language=EN.
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1 Performance of a six-story reinforced concrete structure in post-earthquake fire July 2010 NRCC-52689 http://www.nrc-cnrc.gc.ca/obj/irc/doc/pubs/nrcc52689.pdf
2 British Columbia government 6 Storey Wood Shake Test July 2009 www.hsd.gov.bc.ca/video/wood_shake.html
/NOTE TO PHOTO EDITORS: A photo accompanying this release is available at http://photos.newswire.ca. Images are free to accredited members of the media/
For further information:
Natalie Tarini
Communication Manager
Canadian Wood Council
ntarini@cwc.ca
613.747.5544 ext. 225