Be wary of anyone that tries to tell you how to put out your next fire.
When America Burning was published in 1973, one of the primary conclusions the report reached was that residential fires were at the root of the American fire problem, resulting in the most civilian and firefighter injuries and fatalities and property loss than any other category of fire. Fast forward to the 21st century, and it is difficult, if not impossible to argue against the fact that the residential fire problem remains our most serious fire threat.
A telling recommendation included in the report was that “the fire service needs better training and education”. It’s pretty clear that between 1973 and present day, there have been vast improvements in this category. There will never be perfection in our abilities to execute our duties; however, striving for perfection must still be part of our culture.
Since 1973, along with improvements in our training and education have come significant changes in the environment in which we operate – this is the 21st century firefighter’s “office”. These changes compel us to not only train for our new environment, they also require us to apply the knowledge to the fire ground accordingly.
The 3 Cs: Construction, Contents, and Conditions
Let’s take a look at three very important aspects of the residential fire ground and examine how they can and should impact our strategy and tactics:
First and foremost, we must be familiar with how our “office” is constructed. Why? Because as firefighters, it is critical that we are able to recognize the actual threats posed by these construction features.
The two most common residential construction types are Type III (Ordinary), sometimes referred to as “brick construction”, and Type V (Wood Frame). Within these categories there are additional building features that we, as thinking firefighters, must know and understand.
Typical Type III Construction
Type III features include brick or masonry exterior walls and interior partitions of lathe and plaster. Numerous concealed void spaces usually exist, and inherent fire-stopping between floors may not be present. Knowing these features helps us to understand that a fire in a type III dwelling can travel extensively in the concealed spaces, both vertically and horizontally. Although these dwellings are typically “well-built”, interior renovations and older features such as fire-cut joists (slanted cuts in floor joists that cause the floor to fall down rather than push out when weakened by fire) increase the hazards faced by firefighters.
Fire Cut Joist
Type V features include walls, floors, and, roof structures constructed primarily of wood. Modern construction relies heavily on the use of “lightweight” wood frame members, in other words, trusses that are inherently strong when intact, but fail quickly as compared to legacy construction that uses 2X10s, 2X8s, 2X6s, 2X4s, etc., under fire conditions. Fires in lightweight wood-constructed dwellings can result in collapse much faster than in legacy built type V dwellings, creating a serious threat to firefighters operating inside and around these structures. Balloon frame construction further increases our risks because there is no inherent fire-stopping between floors to limit vertical fire spread.
Understanding the construction characteristics of our “office” is the first step to being successful and safe as we carry out our assigned tasks.
Typical Type V Construction
It’s this simple: The contents typically found in our “office” burn faster than ever before due to higher heat release rates (HRR). We are now surrounded by items we could essentially classify as solidified gasoline. For comparison purposes, a small trash can fire can produce 30 kilowatts of energy (heat). An overstuffed chair might produce 2 megawatts of energy. A burning overstuffed chair alone can produce enough heat to cause a flashover in a compartment (room) in short order.
Courtesy: PA State Fire Academy
When combined with the features of modern type V construction (lightweight wood frame members and large open spaces), the result is usually faster fire propagation (spread), rapid changes in fire dynamics, shorter time to flashover, reduced escape time, and reduced time to collapse.
Another unfortunate reality that is increasingly found in every residential environment is “heavy content” conditions. The presence of what some refer to as hoarding conditions poses numerous additional concerns to us as firefighters, especially when conducting an interior attack.
Courtesy: Ryan Pennington
Conditions dictate strategy and tactics, not the other way around. Our approach to how we extinguish our next fire must result from a thorough examination of the conditions we are facing and an understanding of how these conditions are impacting our “office” and anyone inside the structure.
Key indicators often include: Identification of flow paths, color, volume, density, and velocity of the smoke, neutral plane height, percentage of fire involvement on arrival, how long it will take before water is applied, and where the fire is going (it will move from hot to cold; high pressure to low pressure).
The most critical aspect of establishing our strategy is a proper size-up. Our size-up starts with realistic assessment of factors such life hazards, response time, available manpower and presence or absence of a water supply. From there, we can engage in a 360 degree “tactical” size-up. The tactical size-up must take into consideration the 3 Cs and apply them properly to the tactics you choose. The only way to do this is to physically walk around the structure – you can’t conduct a proper size-up from the front seat of the apparatus or chief’s buggy (although extremely large structures may warrant a motorized 360).
- What is the construction type?
- What is the size of the structure and how many stories is it?
- What can you identify or assume about the contents of the structure based on your knowledge, training, and observations?
- Where is the fire, and where is it going? Do you use a thermal imaging camera (TIC) to assist you in determining fire travel and possible victim locations (Tactical 360)?
- Can you identify the flow path(s)?
- Are there indicators of heavy content?
- Are there access problems?
Courtesy: William Dill
Just as it was in 1973, America’s biggest fire problem is still the residential setting. The difference is, our “office” environment has changed drastically in the last few decades. Properly applying what is learned and practiced in the training environment is critical to a firefighter’s success, safety, and survival. Knowing, understanding, and applying the 3 Cs will go a long way toward increasing our chances of fire ground success.
Chief Dan Kerrigan
Sr. Staff Correspondent