Article and photos by Brett Snow
Whether it is your first day or 20th year in the fire service, there are situations and events that you have yet to encounter. Even the most experienced firefighter reaches a point in his career when he feels he has met all of the challenges his town or district has to offer, such as opening roofs and doors and stretching lines into the type of structures that are most commonly found. Let me remind you: A firefighter never reaches that stage where he knows all there is to know.and cannot learn anything new.
I had one of my many “learning” experiences while I was ventilating a church roof. I do not consider myself an experienced roof-man, so there are many things I have yet to learn. This particular incident involved cutting a flat roof constructed of 4 × 4 tongue-and-groove decking.
The first-arriving companies reported the fire to be in the basement of what appeared to be a two-story church. Heavy smoke was pushing up the front glass-enclosed staircase; no flame was visible. The structure over the fire was two stories and had a flat roof. Because of the fire’s location, we placed our initial ventilation hole over the staircase and then extended it to the pipe chase area.
During the operation, I found that the chain saw was struggling to cut a distance of 10 inches. Although this is not the saw we typically take to a flat roof, it is a roof saw, and I wanted to test its performance. One chain saw, three roof saws, and two wood blades later, the initial hole was completed. What we did not know was that the decking was not the common 1 × 4 board. After we attempted to pull up the boards, we discovered the 4 ×4 tongue and groove.
Because of the construction of this style of decking, it is quite difficult, if not impossible, to pull up the boards, forcing the ventilation crew to have to push the material down into the structure. Thus, the size and weight of the section being pushed in can fall on the companies operating inside. The section that was pushed into the stairway was about a four-foot-square chunk; it fell approximately 15 feet to the lower landing. We were lucky that no companies were in that location at the time.
(1) Preplanning will help you determine if a particular structure has tongue-and-groove decking. Assume it is present until proven otherwise, especially in older warehouses and churches.Click to enlarge
(2) The previous two photos are from a building that had 3 x 6 tongue-and-groove decking. A firefighter fell through the roof of this structure, falling more than 54 feet.Click to enlarge
(3) A close-up view of the decking. Click to enlarge
(4) Another close-up view. Click to enlarge
Also, with this size of decking, it is a sure bet there will be a wide span of rafters or support beams that will most likely be eight feet or more. Being unaware of the span between supports can create a cantilever effect and cause firefighters to fall into the hole. Again, luck was on our side. The span of the supports over the stairway were more than eight feet apart–the thick rubber roofing material was the only thing that kept anyone from falling in.
Combatting The Dangers Of This Style Roof
To prepare against the hazards of this type of roof, first, remove the roof material and expose the decking. Remember that there is a variety of dimensions of tongue-and-groove decking: 4 × 4, 3 × 6, et cetera. If it is a 4 × 4 tongue-and-groove roof, cut small two-foot sections out at a time and extend the hole while standing on uncut ends. This will reduce the size and weight of the material being pushed in and minimize the chances of firefighters falling into the hole.
This method is was derived from in-house discussion with experienced coworkers. There may be other ways to successfully open this style of roof. If you have a 4 ×4 roof decking in your district, it may be to your advantage to discuss it with your department and formulate a coordinated plan for vertical ventilation.
Brett Snow has been a member of the fire service for 21 years. He has been with the Chicago (IL) Fire Department since 2000; he is assigned to Squad 2. Previously, he served on an engine company. His career also includes having been a member of a volunteer department in a small farm town, serving as a paramedic, and also serving as a member of a fire protection district in a Chicago suburb.
Subjects: Building construction, vertical ventilation, roof work, truck company operations, tongue and groove roof decking.
