Ken Bailey: Diagnosing Roofs

By Ken Bailey

The recent Underwriters Laboratories (UL) study on vertical ventilation has certainly sparked some debate about the use and effectiveness of vertical ventilation.  As with any good argument, it is doubtful that we will resolve the issue any time soon.  Across the country, many fire departments have found value in the use of vertical ventilation, while others have either shied away from it or are now reevaluating their concepts and considering moving towards other options. At the very least, the UL study has given us more to discuss around the kitchen table.

For the folks who support vertical ventilation, I propose the following question: What thought process has been put into how we operate on the roof to provide for a safe, predictable, and effective roof operation? For those who have moved away from vertical ventilation I ask the question in reverse, If you could provide for a safe, predictable, and effective roof operation, would you reconsider putting this tool back in your tool box?

What You Don’t Know That You Don’t Know

The natural instinct for many of us is to believe that our mentors and instructors throughout our career were the “best of the best” and provided us with the “best” methods and techniques for doing our job. If there were a better way of getting things done, they would have shared that with us.  Further, we all seem to work for the “best” fire department in the world; and if the “best” fire department in the world does things a certain way, then that is the best way to do things. Thus the cycle perpetuates itself into tradition or maybe more aptly dogma. 

For me the story is much the same until I started to realize that there are many paths up the mountain and perhaps–just maybe–there are others out there who have a better way of doing the same job. With this in mind, our department ventured out to learn from some of the busiest fire departments in the country in hopes that we could create some best practices that fit our needs.  After numerous visits and training sessions with firefighters from Los Angeles, New York City, and Dallas, among others, we have developed some best practices that work well for us and perhaps can add value to others as well.

Roof Diagnostics

When I was taught roof operations initially, the concept was very simple: Someone would tell me to put a hole in the roof, and I would set a ladder, climb up on the roof, run over to where I was going to operate, and then proceed with cutting the hole as close to the fire as possible. There was little to no thought about how I would travel across the roof; and, honestly, many times it was done with a blind hope that I would get there and back safely.

During our journey of trying to develop some best practices, we started to learn about the concept of roof diagnostics, a technique routinely used by some of the busiest truck companies in the City of Los Angeles (special thanks to the bubbas from Task Force 33).

The biggest take-away from this effort was that more thought was put into getting to the hole than the actual cutting of the roof.  This effort is designed to make roof operations three things safe, predictable, and effective.

Ladder Placement

This article addresses only residential work, which is approximately 80 percent of our fires. Prior to getting on the roof, we need to have a consistent and thoughtful placement of our ground ladders. For us, that came to mean that we place our ladders away from the fire and preferably close to a corner. Placing the ladder on a corner accomplishes two basic things: first, it puts the ladders out of the way of operating crews and, second, it provides for a place to get on “good” roof.

Two important parts of this effort are to get the proper climbing angle and extension from our ladder. For us, this is not a 70-degree angle but rather an angle that ensures that one rung meets the edge of the roof. This small detail allows for easy transitions from the roof back on to the ladder and avoids the precarious hunting for a rung. Further, we want the ladder to extend a safe distance above the roofline, which ideally is more than three to five rungs.  We prefer at over five rungs for a couple of simple reasons.  The act of bending over to grab on to a ladder places a firefighter in the position of easily losing his balance, especially if carrying a saw or tool.  It’s a much safer feeling to climb down the ladder from a standing position. Plus, when visibility is bad because of smoke or darkness, we have found that a ladder that is fully extended above the roofline is much easier to see and to get to, especially if you’re in a hurry.

Crew Orientation

We believe that the officer should be the first one on the roof and should be carrying the sounding tool and that the firefighter will be the next member up and be responsible for carrying the saw. This order does not need to be etched in stone; however, in any case, the person with the most experience should be the sounding member and the firefighter or less-experienced member should be on the saw.

The expectation is that the officer is looking at the roof conditions and evaluating findings in the context of the fire conditions present prior to getting on the roof, allowing for fact-based decisions.

Making It to the Hole

The firefighter’s immediate action on making the roof is to step to the opposite side of the ladder from the direction of travel and place an inspection cut. This inspection cut is a diagonal cut made with the saw until coming in contact with a roof structural member (rafter). On making contact with the structural member, the cut is extended about four to six inches beyond the structural member and the saw is removed. An “L” shape cut is then placed around the structural member to create a small triangle, which, in the end, permits a view of the rafter, roof decking, and roofing material. This simple 15-second act provides a lot of information for the roof team and eliminates much of the guess work. For example, what kind of structural members are you dealing with (lightweight truss or dimensional lumber)? Is there a rain roof? What are the thickness and condition of the decking, and how many layers of roofing material are there? Based on these facts, will this take longer than you were estimating; do you have enough people and the right equipment to complete the job?

Now armed with a little more information, you can start to make some decisions based on known building construction variables.  Can you cut the hole over the fire, or do you need to give up space for time—that is, if the hole will take more time to cut than conditions over fire will allow, do you cut the hole farther away from the fire? Can you tell from the inspection cut if you have extension into the attic space?  

Once these factors are assessed and a decision on where to cut is made, the officer heads towards the area of operation while aggressively sounding the roof the entire way and traveling along the load-bearing walls as much as possible. We are completely against traveling “cross country” towards the location where the hole is.

Finishing the Process

Having completed the inspection hole, the firefighter follows the officer’s steps along the load-bearing wall and begins making the cut where indicated.

Prior to leaving the load-bearing wall, if there is some concern about the conditions underneath the decking, there is nothing wrong with making a small triangle in the decking. This is to check whether the decking you are about to walk on is being affected by fire.  If you have heavy smoke or fire pushing through this hole, it’s time to reevaluate the plan, using what you know from your inspection cut.  This really should be the call of the firefighter with the saw and based on the conditions presented on laddering the roof. If it is known to be a simple room-and-contents fire, perhaps this step is not needed; although if significant extension into the attic is suspected and you are dealing with oriented strand board decking or poorly cared for roof decking, I certainly would like to know if I was over fire.


The method and manner in which you decide to cut the hole was not the point of this article, though my travels have opened my eyes to many options that seem to work well for the fire departments using them.  My point is to show the utility and even necessity of exploring and determining what you are dealing with when getting up on the roof.  Using roof diagnostics to remove some of the guessing will allow you to more safely, predictably, and effectively open the roof to support the crews below.

I for one am a big believer in the benefits of vertical ventilation, although I also realize that it is a tool to be used at the right time and the right place. I do not believe that vertical ventilation is an offensive or a defensive tactic, nor do I believe it is anymore dangerous than other fireground tactics. However, I do believe that we as an industry must be thoughtful about our actions and respect the benefits of an in-depth knowledge of building construction for our truck crews.

The inspection cut performed by the firefighter as soon as he got on the roof. As you can see, he located the structural members, determined that there is only one layer of shingles and they are dealing with 5/8-inch plywood, which appears to be in good shape. There is no smoke or charring, and it appears that the fire has not yet extended into the attic. (Photos by author.)

Crews made a smoke indicator hole, which is a small triangle, to see what the conditions were underneath them. In this case, they have some charring but no smoke. This smoke indicator hole was made about half way between the ladder and the area they were going to be operating in. This quick indicator hole can be useful when there is some doubt about what is going on under the roof decking and you are about to move away from the load-bearing walls.

With the ladder positioned to ensure that the lip of the roof and rung meet, the firefighters’ transition back onto the ladder while carrying tools is simplified.


KEN BAILEY, a 19-plus-year veteran of the fire service, is the chief of Travis County (TX) Fire Rescue. He is an associate instructor with the PL Vulcan group, a guest instructor at the Texas A&M Fire School, and a regular guest instructor at several rookie schools. He presents course work for large and small fire departments. He is active in the USAR community and serves as a task force leader for TX-TF2.

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