To a firefighter, building construction is the analysis of how structures are built, what they’re built of, and the effects of fire on those materials and the connective structures used to build them. Notably, it takes into account:
- The likelihood of building failure,
- What could fail,
- The causes of failure, and
- The consequences of failure.
So, what's the point of learning about building construction related to the fire service?
Building Technologies And Their Effect On Structural Fire Dynamics
New building technologies are on the rise. Builders are always looking for new and improved ways to build ever more cost-effective structures while still ensuring that they can carry the same or more weight. In many cases, this ends up reducing the physical mass of building structures because the materials used to build them are newer, stronger, lighter, and less bulky than in the past. In some cases, it’s even possible to remove certain building materials altogether because their function in the structure has been replaced by other multi-purpose components.
However, although less building materials equals less cost, the danger from a fire fighting perspective is that the resulting reduced building mass may adversely impact the building’s structural integrity when faced with a fire situation. In other words, there is now a very real danger that these buildings will collapse a lot faster once a fire takes hold.
As a case in point – traditional wooden framed buildings can take up to 20 minutes to collapse after a fire gets going. If you think that’s pretty fast then consider that a modern, lightweight timber building may take less than 8 minutes to reach that same point of collapse. That’s 12 minutes less time available to get trapped occupants out.
Architects and engineers are also constantly pushing the structural limits of available building materials, often to the detriment of structural integrity from a fire dynamics perspective.
The Use Of New Building Products Impacts Fire Dynamics
New building components, including greener, lighter, and synthetic products, and modern designs that are intended to improve the efficiency of buildings, can have the reverse impact in the event of a fire. Glues and other chemicals in some of the newer construction materials for example alter burn patterns and can give off dangerous gases. Larger empty spaces change the way fires expand. And so on.
Combine these things with reduced structural bulk, as well as the corresponding risk of faster structural failure, and you begin to appreciate the difficulties faced by fire fighting crews. Today more than ever fire fighting is about getting enough of the wet stuff on the primary areas of hot stuff as fast as possible in order to save as many lives as possible. There simply isn’t time to do much more than that.
All Buildings Will Burn, But Some May Burn Far Less Than Others
It’s an accepted fact that a building’s contents will cause it to burn to some degree because many of those contents are flammable. There’s also no doubt that modern building trends like the desirability of greener structural systems and building practices, and the increasing use of synthetic, composite, and engineered materials, are literally changing the fire dynamics of buildings. This latter issue dictates the extent of fire damage that will happen to the actual structure of the building.
For this reason, firefighters need to be well versed and well trained in the various types of construction, as well as the materials and connections that go into each one. They should also know how fire affects these elements, as well as the potential for failures and the consequences of those failures. Lives in fact depend upon it!