You don't engage the chain break when still in the cut. Full RPM's until out of the cut and then let the RPM's go down then engage chain break. You can make the chain jump off the bar if you engage the chain break when running full RPM's. In my opinion if you have to reset your footing then you engage the chain break other than that you don't have to engage the chain break every time. Just slows the operation down. Also as shown in cut one you never take your hands off the saw. You run full RPM's until out of cut bring RPM's down then roll your wrist downward to push on the chain break. Especially running high RPM's and you take a hand off the saw things can end badly especially if its a carbide big tooth k-12 with the feet. Very Dangerous. Train Like You Fight!
Good video. I was a former volunteer firefighter and I was a certified firefighter 2 and we did those types of training. We done three realistic vertical ventilations during a real fire during my 5 years of service with my Dept. It sure is important to do vertical ventilation it works. It should only be done with safety in mind. It looks easy but wearing all that gear makes it hard so practice while wearing the SCBA is important. All firefighters need to be aware of the the two firefighters on top of roof. I took a college course and became certified before I was able to do interior firefighting. So training videos are important. We had weekly training. Knowledge of firefighting techniques are essential in structural firefighting. Also you have to wear SCBA while doing the ventilation. Department store roofs are dangerous they cave in quickly. So don't risk going on top of a building like Walmart.
We teach that that your #1 and #3 cuts are reversed for us. We scribe across the roof to find the rafters on our 1st cut so when you roll the decking you roll a full span section. We also plunge the saw straight down until we hit a rafter, that was more of the chain hits the face of the beam and you can feel the rafter. When the saw is at a shallow angle its more likely you will cut through a good portion of the rafter and not feel it as its a lesser exposure to the chain.
We just performed this drill. Cutting above the fire is ideal, otherwise the fire will "chase the opening" meaning you may have additional fire spread due to the vent hole. Also, make sure cuts and ladder are on the windward side close to the peak to take advantage of drafting.
How do you get the ladder up too the roof top? Like, put another ladder on the side of the house, climb it, then have someone else hand the hook ladder up too you? And whats the point of cut #2?
