By Ted Corporandy

In the MARCH/APRIL 2008 ISSUE of Fire Nuggets, flat-roof ventilation of multiple dwellings was discussed in detail. Because of the number of considerations that must be weighed when confronted with a flat roof the tasks are significantly more than those presented by peaked roofs.

Vertically venting any structure, whether it is a flat roof or a peaked roof, is inherently dangerous due to the fact firefighters are operating above an inferno. With the sloped deck of a peaked roof, negotiating this type of surface compounds the unsafe nature of the operation. For that reason firefighters should be extra mindful of the fact that peaked roofs are generally more dangerous to operate on than flat roofs.

Once the decision is made to open (place a hole in) the roof, firefighters must be steadfast in their mission to provide relief to those below as rapidly and as safely as possible. It is a matter of getting on the roof, opening up, and getting off.

A recent fire in a three story frame, occupied multiple dwelling, provided the perfect example of a “vent happy” truck crew. Upon arrival, firefighters found flames issuing from windows on the second floor. Heavy smoke was also visible extending to the top floor. The entire first-due ladder company went to the roof and commenced cutting a hole giving rise to the following questions:

1. Was it necessary to open the roof?
2. Who was addressing the need to conduct a primary search?
3. Who was addressing the need to provide ladders to upper floors?

The roof is opened (cut) when fire is on the top floor, in the attic space, or in a balloon framed building regardless of fire location due to the high likelihood of fire spread through concealed stud channels to the attic and horizontally through joist spaces. There will be some exceptions. In this case fire was not on the top floor and an immediate search for victims was imperative. In this particular jurisdiction a normal first alarm assignment includes two ladder companies, each with a compliment of four firefighters and one officer. Since the second due ladder had not arrived, a more practical use of personnel would be to split the crew with two firefighters accompanying the engine company and the first line, to search the fire floor while the officer and a firefighter conduct a search of the floor above. Prior to entering, a ground ladder could have been placed to an advantageous position on the fire floor while the apparatus operator could position the aerial to the windows on the top floor. Subsequent laddering, venting, and search requirements could have been handled by the second arriving ladder company.

Another situation which might be categorized as “vent happy” occurred several years ago in a large west coast city. A video clip made the rounds by e-mail and many firefighters have had the opportunity to benefit from watching the mistakes made. The fire was in a two story single family dwelling on the second floor. The second floor appeared to be only about 12 feet by 16 feet and had fire blowing from the large window on the “C” side. Very heavy smoke could be seen from large windows on the “A” and “D” sides and were close to “blowing”. The roof was a typical composition shingle with only about a 3 in 12 pitch or less. Two firefighters, one with a saw the other with a hook, bent on opening the roof, placed their ladder dangerously close to the upper floor window and began their task of furiously opening up. In short order all of the windows blew pushing flames far above the roof line and engulfing the ladder. Finally realizing they were in an untenable position they began their frantic attempt to get off of the roof. It looked pretty grim until firefighters on the ground seeing the drama unfolding, repositioned the ladder and protected the firefighters with hose streams. They barely made it but no doubt suffered some type of burn injuries. There were valuable lessons learned with the following questions addressed:

1. Was it necessary to open the roof?
2. Why was the ladder placed so close to the window?
3. Why wasn’t the firefighter with the hook watching out for a change in conditions?
4. Where was the chief?

The answer to question number one is a resounding NO! You will note that earlier in this piece it was stated: There will be some exceptions. This is a no brainer when you evaluate the risk versus benefit. With a low pitch roof and small area involved a much safer and more efficient action would be to take the large windows on all sides of the upper floor. This could have been accomplished from a safe position on a ladder or long handled hook from the ground. In fact, in most cases of fires involving a single family dwelling where you are confronted with a room and contents and fire has not extended into the attic space, it will not be necessary to open the roof. Simply taking a window while the engine company is making the push will give you the desired results without cutting the roof. More importantly, it frees up the roof firefighters to conduct a primary search. Regarding question number two, when placing ground ladders avoid laddering over or near windows or doors that have a high probability of exposing the ladder to fire, heat and smoke (see Photo 1 below). If left with no other option, then have a charged hoseline at the ready in the event it is needed. Photo 1 also reinforces the safety measure of having at least two ways off of the roof. While not always possible the consequences of not having alternate escape routes is obvious.

Questions three and four above are rhetorical. You know the answer!

When firefighters arrive on scene to a working fire and it is determined that the roof shall be opened, firefighters should remove the appropriate ladders (most likely a 24’ or 35’ extension ladder and a roof ladder if necessary). The roof ladder, saw, and roof hook can all be placed in the bed of the extension ladder and carried to the point where it will be raised. Once the extension ladder is placed at the correct location the saw firefighter will be the first one up the ladder with the saw (with strap) on one shoulder and roof ladder on the other. Once the roof ladder is placed to the ridge, he or she will proceed to the top of the ladder and start the saw[1]. The irons firefighter will be the second one up the ladder and drive the point of the Halligan bar into the roof, with the shaft pointing down slope towards the eaves (see Photo 2).

If the Halligan does not easily penetrate the roof, the flathead axe can be used to drive it into the deck further. In this position, the adze/point end of the Halligan will provide additional stability for the saw firefighter who can place one foot on the ladder and one on the Halligan. It is interesting to note that some firefighters advocate cutting a small hole in which to insert a foot. Remember, you are opening the roof because there is fire beneath it. This is a good way to get burned. If it is heat and smoke free beneath your proposed cut then the obvious question is why are you cutting there? The hook firefighter will be last up the ladder and may or may not access the roof. He or she shall, however, stay in close enough proximity that the hook can be passed up the roof to the saw firefighter. As soon as the roof is opened, firefighters need to pick up and vacate immediately.

When cutting the roof deck with a chain saw[2], insert the blade into the roof deck at least 10 inches and as near vertical as is practical. Cut until you feel a rafter then draw the saw up and over it. By operating with the saw near vertical more surface area of the chain will contact the rafter making it easier to detect and thus preventing you from cutting through it. Resume cutting until you come to the next rafter and repeat the process. This is called rolling the rafter (see diagrams A, B, and C). Some firefighters like to mark the location of the rafter with the saw. It helps to locate subsequent cuts when louvering the segments (see diagram D).

If louvering segments, I prefer to remove them completely, allowing for a totally unobstructed hole. In some instances, however, it may be advantageous to leave the segments, particularly where wind is affecting the vent process. By louvering, as depicted in Diagram D, wind is aiding the vent process whereas if the segments were reversed smoke would be driven back into the building.

Diagram E below illustrates the cut sequence. It is best to operate from the far point of the hole and work back towards the ladder. A mistake often made is to overreach with the saw when making the far cuts. The surface on which you are operating is pitched and dangerous. Trying to do too much is not worth the risk. You are not going to be able to make a large hole. If you are lucky a 3 foot by 3 foot hole will be the norm. The point is to get a hole in the roof as rapidly as possible to get the smoke, heat, and energy up and out. Note that cut 5 will give you a knockout or hole as a purchase point with a hook. If you are segmenting and louvering the pieces, this will not be necessary. There are some firefighters who recommend placing the knockout on the far side of the cut so that the piece can be pulled towards you. It has been my experience that most firefighters have difficulty making this cut and overextend themselves resulting in stumbling or falling. With the knockout on the near side of the hole, the piece can be pulled downward thus avoiding any overreaching.

Conclusion

This represents one of a number of different ways vertically venting a peaked roof can be achieved. It can be altered to better fit your needs or staffing situation. This method assumes a pitched roof greater than 4 in 12 (thus the roof ladder) and is not accessible by aerial ladder or elevated platform (the safest means by which to open a roof). Regardless of your approach to opening a roof, the bottom line is to have a game plan, designated positions, and be proficient at it. Whatever you decide to call each position or how you cut the roof, it is clear that it will take a good degree of coordination and discipline. You do not need a roof on which to practice. It can be acted out on flat ground. No excuses!

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