Truss Roofs: Do You Know Where the Firefighter Killer Hides?

Lack of recognition of key aspects related to building construction is one of the top five common threads when analyzing firefighter fatality case studies. A good number of times, this lack of recognition can be attributed to a hidden danger that is not...


The best remedy however is to know the buildings within your response district. As previously stated in some of the prior articles in this series; company inspections or preplanning offer great opportunities for us in this regard but are not necessary to accomplish this goal. Taking a few moments to look at things after a false alarm activation or medical run prove to be invaluable at 3 a.m. when smoked is banked down to the floor level in that same building.

Knowledge of construction features as well as what "secrets" are contained within the buildings in our response areas remains paramount for us to have the ability to take the proper actions on the fireground. Many times, renovations take place without proper permits or inspections and can prove fatal even when carried out to the standards set forth in building codes.

An important point to remember is that any type of alteration to a truss system will more than likely present additional danger when placed under fire conditions. The fire mentioned in New York had office spaces located between the trusses, it is in this area the fire supposedly originated. The truss space in the Hackensack, NJ, fire was covered by heavy lathe and plaster and was used for additional storage. The incident that took place in Chicago had unprotected polystyrene insulation glued to the bottom chord of the trusses which contributed to rapid fire spread. All of these listed were alterations to a system that is already a hazard to our profession.

The void space created by a bowstring truss can allow heat, smoke and fire conditions to go undetected causing a false sense of security for firefighters operating beneath it. Because more surface area is exposed to flames than with standard construction, collapse can take place in a much shorter time frame. At many incidents involving trusses, crews inside the building reported that they have little or no signs of smoke when heavy smoke may be visible from the roof on the exterior. Communications and updates between interior and exterior personnel must be continual when dealing with any type of truss construction.

Any building on fire that is suspected to be truss construction must have ceilings opened quickly to expose the truss area for inspection. If trusses are exposed to fire on inspection, it is highly recommended that crews be withdrawn and defensive measures be utilized. There is no way of knowing exactly how long the fire in the truss space may have been burning and what damage may already be done. It is important to note however, that firefighters must exercise caution when opening up ceilings in truss construction to eliminate backdraft or flashover potential once air is fed into the void space.

It is imperative that we take the steps necessary to change our tactics and the way that we act on the fireground, especially when it comes to risk versus benefit analysis. Take the time needed to "read the structure" and get your crew out to look at buildings inside your first due area. Our job will always contain danger no matter how hard we try to control it but why should we continue to ignore the factors that we can control and not learn from our own mistakes?

Are you prepared to meet the challenge if it comes during your shift?


Jeffrey Pindelski is a 16 year plus student of the fire service and currently a battalion chief with the Downers Grove Fire Department in Illinois. He previously served for 12 years as a firefighter and lieutenant on the truck and heavy rescue companies. Jeff is a staff instructor at the College of Du Page and also instructs courses at the Downers Grove Fire Academy. He has been involved with the design of several training programs dedicated to firefighter safety and survival and is the coauthor of the text R.I.C.O., Rapid Intervention Company Operations.