Using natural openings for vertical ventilation should always be considered prior to cutting a ventilation hole. Many times skylights are quicker to open and in a perfect location. Skylights are generally located over hallways or stairwells in multiple dwellings. Ventilating the hallways and stairwells has several benefits.
Venting the hallway and stairs is beneficial to everyone in the fire building, firefighters and civilians alike. Allowing the smoke to lift in the hallway and stairs will assist civilians with evacuation and firefighters make their way in. This will allow the forcible entry team to more easily locate and force the door to the fire area. Relieving the hallway and stairs of smoke will also make it easier for the engine company to stretch and flake out their line; we all know the benefits of getting the first line into operation quickly.
After opening the skylight by either breaking the glass or hinging the entire assembly open your work is not complete. The vertical walls that run from the skylight to the ceiling are known as “returns”. The returns must be opened up with a hook to check for fire extension into the cockloft. This is critical information not only for the members operating on the roof but the incident commander and interior companies as well.
Opening the returns also gives you a chance to see how the roof is constructed. As you can see in this picture the roof is parallel chord wood trusses. That information combined with fire conditions in the cockloft can have a direct impact on the amount of time members spend in the building or on the roof.
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