When performing vertical ventilation on a pitched roof, there will be times when a well-trained Saw operator will outpace the Hook firefighter as more openings are made. We base the need for expansion off of the conditions exhausting from our holes and radio communication with the Engine Company. In todays over stuffed domiciles consisting of inexpensive, highly synthetic furnishings, immediate expansion of the initial opening has become automatic, at least for us.
After expanding the initial ventilation hole, the Saw firefighter may need to put in double duty and pull their own work. In this instance, setting a running saw down onto a pitched roof could result in the saw sliding off the roof. What to do?
You have several options. You can set it down onto the roof up against a vent pipe and hope that it doesn’t slide off. You can clip it or insert the blade through the rungs of a roof ladder if you have one topside. Or, simply run the saw at full RPM, make a kerf cut, set the brake, and insert the bar of the saw into this kerf. This eliminates any risk of the saw falling off the roof and is much faster than anchoring it to a roof ladder. Some may be wondering what a kerf cut is? A kerf is a single cut made into the roof decking that is the thickness of the blade. Once the kerf is made, apply the brake and lower the saw into this cut. This will keep the saw in one place so that you still have it at your disposal and will prevent it from falling and injuring a firefighter on the ground. This works equally well on a steep pitch roof. Generally a rise beginning around 6 or 7:12, depending on the covering and region of the country.
Instead of passing the saw down the ladder to the back-up or hook firefighter, just bury it into the roof on the other side of the ladder. It is important, however, to perform this technique correctly. Please remember that we do not cut with tip of the bar. Furthermore, chainsaws are designed to be used right-handed. Thus the bulk of the motor protrudes and follows the left-hand grip bar. In the picture below you will see that the saw was inserted with the motor facing down the pitch or rise of the roof. This is the correct way to perform this maneuver. In this position the motor prevents the saw from backing out of the roof decking. If the saw is inserted into the roof in a different position, and the brake wasn’t applied prior to insertion, the chance does exist for the saw’s blade to come into contact with a roof member, ducting, or utility pipe, thus backing itself out of the roof. This technique is by no means cutting edge. Just a real world tip that we don’t see utilized very often and therefore thought that we’d share it. Anytime we are on a pitched roof and we need to set the chainsaw down, consider utilizing this technique for an all-around safer and smarter operation.
Figure 1: Notice the saw is positioned so that the motor is on the down-slope side of the roof.
Steep pitch saw stowing in the above video...
Side note: A chainsaw with a depth gauge or chain guard will not allow the operator of the saw to perform this technique due to the depth gauge being wider than the bar. It is in the opinion of the author that the use of depth gauges can make the ventilation operation very precarious and somewhat operationally ineffective. When the adjustable section of the depth gauge vibrates lose and slides forward it now has the opportunity to come into contact with a hot, sagging blade. An extremely hazardous scenario presents itself in where a very hot chain fails and launches into the air or pieces of the metal depth gauge do the same. Furthermore, by no means should firefighters ever allow the use of a depth gauge to replace the Saw operator’s ability to “feel” and “roll” the rafters or trusses of a roof system with the blade of the chain saw.
Figure 2 Above: Keep in mind the length of the saws bar (20 inch) versus the rise of the roof. If working low on the pitch and you insert the saw into the roof, the saw could come into contact with ductwork, Romex wiring, or utility pipes thus taking the saw out of service.
This is why it is critical to APPLY THE BRAKE prior to inserting the saw into the roof !!!