Do different building types and building materials have a critical impact on fire outcomes?

On July 25, 2019, we had the honor of inviting Professor Len Garis, a Canadian fire protection expert, to share with us some of his research findings on "Fire Control and Safety in Canadian Wood Structures." His discussion on fire outcomes in different building types provided new insights into the fire safety of wood structures.

Professor Len Garis pointed out that the study was based on 11,875 fires that occurred in British Columbia, Canada between 2008 and 2013, which resulted in 107 deaths and 772 injuries.

During the research process, first, the types of building structures that caught fire were divided into the following five categories.

The first category is exposed combustible structure – open wood grilles;

The second category is protected combustible structures – wooden structures protected with drywall;

The third category is exposed combustible structures – heavy timber structures;

The fourth category is exposed non-combustible structures – steel structures;

The fifth category is protected non-combustible structures – protected steel and concrete structures;

Secondly, we analyze the following aspects and draw conclusions.

The number of fires and casualty rates for each of the above structural types;

The fire spread range of each of the above structural types;

The fire frequency of each of the above structural types;

The fire spread range of each of the above structural types and protected structural types;

Fire control methods for each of the above structural types;

Fire mortality rates for each of the above structural types;

Relationship between structure type and mortality rates in the presence of functioning smoke alarms and fire sprinklers.

Research data shows that the fire spread of different building structure types and material combinations is very similar.

Of the 865 fires that were protected by both smoke alarms and sprinkler systems, the injury and fatality rates for protected combustible structures and protected non-combustible structures were very similar. (Over 90% of Canada's low-density and many multi-story buildings are wood-framed, while unprotected heavy wood structures account for only 1.7% of the total, yet the injury and fatality rates for these structures are zero.)

Therefore, it can be concluded that fire safety is not related to the type of building structure material. In terms of the overall situation of fire spread, whether it is a wooden structure or reinforced concrete, most fires can be controlled in the room where the fire started.

The study also showed that smoke detection systems could reduce the death rate by 38%, sprinkler systems by 69%, and a combination of these two methods could reduce the death rate by 77%.

By installing more reliable and safer fire warning and control systems, fire casualties can be significantly reduced. As a supplement to research on building structural materials, we can rely on reliable fire control systems to extinguish fires before they spread to the structure, making building structural materials completely ineffective against fires.

Professor Len Garis has over 30 years of experience in firefighting and has served as fire chief in fire departments in several Canadian cities. He has also participated in academic research at several Canadian universities as a visiting professor and provided relevant technical advice. He has also published many professional papers and books on fire safety and fire control.