Vertical ventilation: Proposing a new way to cut a big hole
This simple method for a quick cut on a pitched roof allows for fewer cuts and safer operations
I frequently see video footage of fire scenes, and many times, truck crews with permanently assigned officers going to the roof without any observable plan for performing vertical ventilation. It is obvious in their actions – and even more obvious in their inactions. They fail to lead while on the roof, and they simply point to a general location and garble some orders to their firefighters. More often than not, this leads to poor performance, too small of a vent hole, or abandoning the operation entirely. They find themselves in this position because they fail to train regularly, and they fail to train their firefighters to complete understanding of the assigned task.
Also, if you pay any attention to social media, you will see 100 different ways to perform vertical ventilation. In one video, a firefighter appears to be trying out for a position as a Ginsu chef, essentially flinging the saw around and marking all the rafters with quick bumps of the saw and then cutting and lifting the saw out multiple times in an effort to avoid cutting the rafters.
Here’s a fact: If your saw is not on or in the decking, you are not cutting. If you are not cutting, you are not making progress. If you are not making progress, you are not improving the interior conditions. If you are not improving the interior conditions, you are not helping the victim or the attack crew. And if you are not helping the victim or the attack crew, then what are you doing?
Let’s face it, we need a no-nonsense method of cutting a hole – bigger, faster and safer – when operating on pitched roofs.
A proven method
Here’s one proven method that meets those needs for a pitched roof:
- Step 1: After deciding the location to cut, place the saw blade on top of the ridge. We are not trying to cut through the ridge board, only the decking. Once the saw blade sinks into the decking, pull the saw blade straight down for 6 feet.
- Step 2: Move over 12 inches and put the saw blade on the ridge board again and pull straight down for 6 feet.
Repeat this motion for a total of six vertical cuts from the ridge board 6 feet straight down. In doing so, you end up with a 36-square-foot hole vs. the standard 4x4 hole that only yields a 16-square-foot hole.
There won’t be any top or bottom cuts. How can this be?
Let’s consider the construction methods and materials in pitched roofs. The standard decking on your typical residential pitched roof is only 7/16 of an inch thick. When built with plywood/OSB decking, the top piece of decking is typically cut-to-fit. So, if you cut the total 6-foot vertical cut from the ridge, you will not only cut entirely through the top piece of decking, you will have cut very near through the next row of decking as well, making the piece you just cut so weak that it is easily broken and pulled back onto the roof or pushed in.
These six vertical cuts must be kept to 12 inches. This will ensure that we avoid any possibility that we end up with any decking attached to two separate rafters, requiring the clean-out person to put in additional effort in removing any decking that doesn’t fall in.
This method also works very well with tongue-and-groove decking.
Before you hate on this method, try it. You will see for yourself that it is not only faster, but it is also safer, especially if you are dealing with poor visibility or a sketchy roof.
In using this method, you are not walking around your cuts. You are constantly walking away from your cuts, away from the fire, away from the weakest part of the roof and back toward your ladder.
Why it works
Here are some additional details of why this method works:
Rafters: In using this method and not cutting the top or bottom cuts, as long as you keep your cuts straight, you essentially remove rafters from the equation.
Ridge vents: When I see videos of vertical ventilation being performed on a pitched roof with a ridge vent and visible smoke is pumping out of said ridge vent under pressure, I always laugh a little to myself. It’s not really funny, but over and over, it shows that firefighters do not take the time to truly size-up the roof before making that initial cut and simply start cutting because that is what they were taught to do. If they understood the significance of a ridge vent, they would know that the top cut is entirely unnecessary, as it is not even attached to the ridge board.
When a ridge vent is put on a pitched roof, the decking is cut away 1 inch on both sides of the ridge board. That means the decking is not even attached to the ridge board. Why take the extra time and effort to make the top cut at all?
Heavy smoke: This method is especially safe and effective when humidity is high and winds are low. Oftentimes, when we get on a roof, it is almost like we are inside the structure, as the smoke banks down and reduces our visibility. In using this method, again, you remove the concerns of cutting across the rafters and walking around your cuts. This method also removes the need to cross any cuts when you cannot see the decking at all.
Sketchy roofs: I am not one to advocate for dangerous operations. However, if you intend to place a crew under a roof so they can operate under backdraft-type conditions, then vertical ventilation is called for. If the roof seems sketchy, perhaps weakness caused by age or rot, use a roof ladder. For that matter, use two.
In using two roof ladders, you provide for a much larger and stable work area for the firefighter cutting the hole. When the cuts get closer to the ladder, simply move the ladder closest to the cuts out of the way and continue to cut until the six vertical cuts are made.
Before anyone blows a gasket, remember that there is not a single documented case of a firefighter working from a roof ladder and falling through the roof due to roof failure.
Also remember, we use the roof ladder for two reasons – to work on steeply pitched roofs and to spread the load. Spreading the load applies to sketchy roofs, too – the same sketchy roof you are putting attack crews under. Think about that for a minute. Read it again.
Give it a try
In closing, I want to remind you of the reasons to use or at least try this method:
- It is the same number of cuts as a traditional hole.
- It is faster.
- It is safer.
- It is a bigger ventilation hole.
- It removes the concerns of the rafters being cut.
- It is easier on the clean-out man.
- It is also easier to train your crew to use this method versus all the other methods currently in use around the country today.
Find a roof and try it! Get out and train – and be safe!