Thread: Do you open the roof?
05-19-2001, 06:49 AM #1Plug-UglyFirehouse.com Guest
Do you open the roof?
More food for thought:
2 story wood frame with heavy smoke at the eaves and attic vents. No visible fire.
Open the roof? If so, where?
Break out windows? Which floor?
Open the front door and a rear window and set up PPV?
Take out a first floor window and set up a negative pressure smoke ejector?
Drop ladders through second floor windows?
Bring in a hoseline hoping to perform hydraulic power venting once you find the fire?
Don't worry about ventilation, just get in and find the fire?
05-19-2001, 01:48 PM #251Truck_KFirehouse.com Guest
Well I would have to see more, like an actual picture..BUT, you can Guaran-DAMN-tee that I would have guys with saws on the roof! And guys with hose in the doors, and ladders thrown, and a good "camera man" looking for the red devil.....Sounds like fun!
05-19-2001, 02:53 PM #3BFD847Firehouse.com Guest
I am thinking that positive pressure ventilation and staying clear of roof tops may be very regional. A lot of this is probably due to local building style. I notice a lot of people posting from back east are mor driven to get to the roof. I live in an area of sub-urban/rural. We still have many older balloon style construction but it is declining quickly. I think these style are prime for true verticle ventilation. Most structure fire response that we have are 1 or two story with a large number of split level homes. Very many of these built in the last 10-15 years have trussed roofs. Even if ventilation is performed in the proper manner using roof ladders. If there is significant fire load in the attick. There will not be just a failure here or there. If there is failure in the integrity of the roof it will all go. Meaning your roof ladder don't mean squat. Positive pressure seems very well suited for many types of fire,if done correctly. I am sure I have stirred a few things up but I would like to here other opinions. Mybe positive pressure is also a selection due to man power and equip shortages ie ladder trucks. Most small depts. around us also use positive pressure
Of course just my opinion and .02 cents worth. Looking forward to see other views.
05-19-2001, 05:27 PM #4FREDFirehouse.com Guest
After conducting a size up of all floors (focusing on the top floor and basement). I would most likely open the roof caps and vert. vents then proceed to cut a hole at the highest point over fire for the following reasons.
-Vertical venting will assist in confining the fire by allowing the products of combustion to rise up and not out, thus limiting horizontal extension. This makes operations much safer in that there is less roof area that is impinged with fire.
-It will allow a direct vertical exit for the products of combustion and thus enable the Engine Co to enter safely from below. Reduces chance of flashover.
-It only takes two men to vent the roof vs. PPV which would take at least 4. 1-to set up the fan, 1-ensuring the correct doors and windows are open or closed on the inside, atleast 2 men opening the louver vents (if equipped).
-Safer than PPV, to use PPV one needs an clear path for exhaust, the louver vents provide a inadequate opening. Opening of these vents on either end would be the equivalent of a poorly placed vertical vent hole...it would cause the fire to extend to previously uninvolved areas. If one doesn't have these vents or leaves them in place just opening top floor windows will do nothing for the smoke and heat condition in the attic.
As for breaking out windows...if the smoke and heat condition dictates I would take out a windows on the leeward and windward sides if possible for the most effective horizontal venting.
BFD847 As for truss construction...We have some trusses too. However might I recommend you look at using your Ladder Company's aerial to provide a working base so the men are independent of the roof's support system. But that might not work if you don't send one...I don't know if you do?
Two cents from a fireman.
05-19-2001, 08:16 PM #5FireLt1951Firehouse.com Guest
First off I would want to vent with a window first with a charged line near the door. No visible fire would indicate the possibility of a backdraft situation. I want to know where the fire is located before I would open the roof up. Finding the location of the fire is the primary objective before deciding where and how to vent. You vent in the wrong place or at the wrong time and the fire may very well chase your as@ right back out the door. I'm not there to see the actual situation, size up would dictate when, where and how I would choose those ventilation procedures.
[This message has been edited by FireLt1951 (edited 05-19-2001).]
05-20-2001, 01:36 AM #6ChiefkeoFirehouse.com Guest
Fred, take note that BFD847 mentions not having access to an areial truck. Many smaller departments prefer PPV because of the fact that they can't maintain an independant support system. PPV is SOP for our department. It doesn't require an extra man checking doors your interior crew can handle that as you progress. Also keep in mind that roof ventilation holds a bit of the same problem, if your hole is not lacted properly the heat and gases may not vent effectively because of lowered ceiling, closed doors and other restrictions. One man should be able to open your exit using a window or doorway. So you still are only using the 2 men you would use on the roof only they are in a much safer position. We didn't believe PPV would work that great either until we conducted some training fires making attacks with and without it. We became believers quickly. Maybe its the differnce in construction but the louvers would not be my choice for an exit opening as was stated they are too small and time consuming. Without knowing the smoke level showing other than at the eaves and vents I hesitate to state which floor to make my opening on. But I will say the higher the better. As for taking out a window near the door, everything I've been taught about reducing backdraft potential tells me to vent as high as possible again. If I see signs of backdraft potential it would be time for me to put that roof crew up and open that hole. Plug says there are no flames visible in both PPV and roof venting you must first determine where the seat of the fire is. Smoke levels, coloring and travel may help in the absence of visible flames. As for forgetting ventilation...NEVER! Keokuk paid the ulimate price in a valant rescue attempt when ventilaton may have made a big diference. I wouldn't hit the ladders on the second floor because I may find the fire below me weakening my floor and eliminating my second escape route. I agree with 51_Truck in throwing ladders put only to use as escape routes if the interior team makes the second floor. Depending on the conditions many of the ideas offered may work or may not. Signs of heat level, smoke color, glass condition, any puffing of smoke, smoke locations, wind conditions and all the other details you gather during your sizeup will determine which you use. Keeping both methods up to par and in your arsenal will let you use what is best for each incident.
I shall fear no evil, for I am a Firefighter
[This message has been edited by Chiefkeo (edited 05-20-2001).]
05-20-2001, 09:21 AM #7Dalmatian90Firehouse.com Guest
Well, our 1st in Engine-Tank is usually a couple minutes ahead of the ladder so we have a few minutes to decide.
Let's open the door and get a hose crew to see what conditions are like. If we can get a good idea where the fire is, that might make the difference.
For instance, if it ends up being a room & contents area on the 1st floor, or even 2nd floor, we'd probably setup PPV and horizontal vent first. Even with vertical vent we use PPV 'long as it's not a balloon frame.
If it's a balloon frame and we find fire in the basement or attic, get her open.
05-21-2001, 09:36 AM #8e53NSBFirehouse.com Guest
We first have to LOCATE the fire, we've been using PPV since 1990 and it works great, but in this situation I'll probably be leaving it on the bus. It sounds like in this scenario we have a working fire on the 2nd floor, or worse, the attic, but its still unknown where, possibly in a concealed space (attic). Lets vent the upper windows, pull some ceilings, put the truck in the air with some saws, lets find out what we have and where...Remember: Locate-Confine -extinguish. Keep your ongoing size-up going. The one major contraindication for PPV is fire in concealed spaces.
05-21-2001, 10:58 AM #986RescuetechFirehouse.com Guest
You said wood frame construction. what type of roof. Most of the homes we have have fireman killers in them. We do not have a ladder truck as of now, but would throw necessary ground ladders. Putting crews on the roof might be a bad idea. Heavy smoke from both eaves and attic vents could be problems. Newer homes are more airtight and could conceal alot more fire. Backdraft is definately a possibility. I would pull the vents off and see what happens, have a crew in with a "charged" hoseline and a TIC. Without anymore info, it is tough to have anymore directives. If a backdraft isn't present inside, I would have the crew proceed to the attic area and extinguish the fire. A crew on a ladder outside could make the attic vent hole bigger and go back to old school horizontal ventilation with a fan hung from a ladder on the opposite side. This might confine it to the attic area. Truss roofs scare me and hopefully everyone else here. Without a ladder truck. i would not put a crew on the roof with a fire of this type. Be safe.
05-21-2001, 01:27 PM #10Dalmatian90Firehouse.com Guest
86, this isn't to pick on you, but I've heard similiar things in the past:
Without a ladder truck. i would not put a crew on the roof with a fire of this type
So, would you put a crew with a hoseline UNDER it?
05-21-2001, 02:00 PM #11e53NSBFirehouse.com Guest
Remember the old saying "if it ain't safe to be on it, it ain't safe to be under it"
05-21-2001, 05:23 PM #12LadderCo13Firehouse.com Guest
With out question open the roof. You don't need an aerial ladder for this. A 28ft ground ladder and a 16ft to 20ft hook ladder on the roof is more than enough. The roof men cut the hole, get off the roof, and go to work.
05-21-2001, 05:48 PM #13FireLt1951Firehouse.com Guest
This scenerio leaves some unanswered questions, but I would definitely consider backdraft potential and I would not open the roof immediately. This is why.
Back when I was a young firefighter in 1979, we had a similar situation as discribed by Plug. We were sent to the roof to ventilate (highest point). Well what happened next was something that has stayed with me since that day.
As we began putting the hole in the roof, there was a sucking sound that I will never forget. At that point all the windows in the dwelling were blown out. Needless to say, I have never left a roof faster in my career.
The I.C. at that time had ordered a line stretched and charged to wait about 20-30 feet from the front door, while waiting for ventilation before opening that door and entering. After this fire, when conditions such as this warrant, we decided to vent a window at a high level away from our entry point. If there is an explosion it will still take out a lot of windows, but we aren't caught on the roof at that time.
The fire turned out to be on the first floor. Needless to say after we vented the roof the whole first floor was engulfed. We new where the fire was then.
05-22-2001, 03:03 PM #14INDY FIREFirehouse.com Guest
There are alot of things to consider in this situation. But more times than not, I would open up the roof. I agree with LadderCo13.
05-23-2001, 09:30 PM #15PBF8TFirehouse.com Guest
The key factors from your question that ring a bell in my head on a size up of this are, Heavy smoke from eaves and attic vents, and no visible fire.
First, no visible fire with heavy smoke means the fire is either in the basement or your dealing with a smoldering fire.
Lets get back to the basics, Convection, when people say "heavy smoke" normally that means the smoke is pushing or moving. This means the smoke is part of superheated air currents. These currents will rise until they meet resistance, ie. the roof. Once these fire gases heat to their ignition temperature, your will have a good fire in the attic. Also Conduction, balloon frame typically has vent pipes running the walls through the building and out the roof. A basement fire can easily start a fire in the attic, along with convected air currents through wall members.
Now, ventilation should be done using natural ventilation to your advantage. Any time you are going to vent the roof you should try to do so first. Allowing the heated air to work by mother nature and out the vent hole.
So Vent the roof, vent high, vent over the fire if possible, cut a big hole, take out the ceiling, get off the roof.
Work with the engine guys, get the roof open while they are sizing up and stretching the line to the interior exposure, the stairs.
If you are limited on manpower, and have possible entrapement. Then stretch the line, use the ground ladders to take out the windows, vent enter and search.
As for Hydraulic Ventilation, this is a secondary method, for the hose guys to vent a small area for better visibility or cooler conditions, this should not take the place of proper vertical ventilation. Dont make excuses for lack of manpower. Small companies need to depend on Mutual Aid. Get the people there.
Now Positive Pressure Ventilation, a tricky tool, you better have alot of experience, and you better know where the fire is located to use positive pressure ventilation. Also the key to PPV is controlling the air flow, without knowing where the fire is and not going inside to set the air flow path, might get yourself in the jackpot. However, once again, if you have experience in it, you might just be able to pull it off.
Only my 2 cents also. Stay Safe, and Be careful.
[This message has been edited by PBF8T (edited 05-23-2001).]
06-06-2001, 07:13 PM #16ryanlori128Firehouse.com Guest
Why not just poke small holes in the ceiling and steam it out?
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