How can you tell which structure fires need roof ventilation and which ones don’t or are too dangerous for it? Jeff Johnson of the Kansas City, MO Fire Department has the answer in his Fire Engineering article.
One thing to look at is the roof, he says. The roof can give you all kinds of information about its safety and the fire underneath it, but only if you know how to read it. We’ve summed up the most important indicators in Johnson’s article in this bullet list.
- Smoke: Smoke rising high into the sky indicates high heat from a more developed fire and greater danger to firefighters and occupants, while smoke hanging around the eaves could indicate less heat or a fire that hasn’t made it to the upper floors.
- Roofing Materials: Asphalt shingles can indicate lightweight truss construction and can hide the signs of impending roof failure. Heavier materials like slate or clay tiles, on the other hand, are probably built on top of more solidly-built roofs and will need more personnel and effort to ventilate. Both can collapse at any time, so don’t take your eyes off the roof for a second, no matter what it’s made of.
- Dormers: A useful roofing feature for firefighters, dormers give you a look into the attic and can be used for ventilation.
- Skylights: Another useful roofing feature, as we’ve noted here before, are skylights. They can tell you if the fire’s worked its way up into the roof and, with a little work, can also be used for ventilation.
- Roof Vents: Both fixed and turbine vents vent heat from attics. Turbine vents are especially useful during a size-up because they spin faster the hotter the attic gets, at least in windless conditions.
- Other Roof Features: Roof features and equipment can warn you of roof collapses if you know how to read them. Keep an eye out for rain guards and flashings raised above the roof line, melting tar, or the chimney and roof pulling away from each other. These are signs for you to get your guys off the roof and maybe out of the structure.
- Fire District: Probably the best way to know how to vent roofs is to know what kinds of roofs are in your district! Visit construction sites, learn about existing buildings, build props and mock-ups of them, and then train, train, train.
Read Johnson’s full article at Fire Engineering.
Fire Engineering, Jeff Johnson, “Size-Up: Reading the Pitched Roof“