Backdraft or Collapse?

[x129K 1,393]

Impressive regardless.......

http://www.youtube.com/watch?v=aTQWNCeCBvQ

[abaduck 123]

Definitely a backdraft by my reading; watch the smoke coming from the attic vent immediately above the door. There's a strong puff of smoke immediately prior to the collapse - and from all round the eaves too. I read that as overpressure in the attic; perhaps someone pulled a ceiling or opened a trapdoor on a charged attic and it blew. Balloon frame construction too, from the way the wall went down as a single panel? Perhaps someone with more experience can check my thinking!

[x129K 1,393]

Definitely a backdraft by my reading; watch the smoke coming from the attic vent immediately above the door. There's a strong puff of smoke immediately prior to the collapse - and from all round the eaves too. I read that as overpressure in the attic; perhaps someone pulled a ceiling or opened a trapdoor on a charged attic and it blew. Balloon frame construction too, from the way the wall went down as a single panel? Perhaps someone with more experience can check my thinking!

From what I read about it - you are dead nuts on

[TAPSJ 30]

I would say collapse. My question is for the Chief in the white hat (At The End) are the sunglasses NFPA regulated??? LOLOLOL

Thomas

[x129K 1,393]

I would say collapse. My question is for the Chief in the white hat (At The End) are the sunglasses NFPA regulated??? LOLOLOL

Thomas

That was also mentioned...short staffing and the LCC had to assist in throwing a ground ladder apparently..not ideal, but real world when you talk anout 2 man truck "companies"...

[abaduck 123]

I would say collapse. My question is for the Chief in the white hat (At The End) are the sunglasses NFPA regulated??? LOLOLOL

Maybe we're both a bit right bro. If you look at the video frame by frame, about 4 seconds in you can see a major smoke 'event' from the attic - at which point the D side wall hasn't moved. THEN the wall collapses. After the collapse you can see the D side is involved in fire from the basement to the ridgepole - balloon frame as I said. So we have an attic charged with very hot smoke and low O2, fire running up inside the D side wall - providing an ignition source and weakening it - pull a ceiling or open a trapdoor introducing fresh air and BANG: a backdraft, an overpressure in a confined space, and the weakest point - the fire-weakened D side wall - collapses.

That's my theory anyway. Maybe it would have collapsed anyway, but it sure looks like a backdraft giving it a shove!

[Tanker 10eng 140]

wait wait, did the wall collapse ?? or did the Backdraft in the attic blow out the brick chimney ???? from what I saw it looks as if the chimney was blown out and down... masonry chimneys are supposed to be free standing structures, and being on the outside of the structure, it would explain why it fell down.... plus if the footer for the chimney settled outward over the years, leaning just a bit, it would not take much force to get it moving... it would also explain why the flames are seen going up and down the interior of the chimney ??

my thoughts...

[Tanker 10eng 140]

plus look at the outer chimney vertical line and the house front corner vertical line, it appears the distance from these 2 points, from the bottom then again looking at the top, is showing tyhe chimney is leaning out ward..... maybe its the camera angle, but thats what I see...

[abaduck 123]

You're dead right tanker - I didn't look close enough. When you look closely it's the chimney that went, not the whole D side. You can still see the ladder standing if you look close enough. My point about the attic backdraft stands tho!

[Tanker 10eng 140]

yes Sir !!!

[IzzyEng4 427]

I've seen this video before. An outside chimney is 90% of the time a non supported construction with houses like this. Even with modern construction today some of these are just ornaments to hide the chimney piping for a furnace. Despite if it flashed or a backdraft occurred, the pressure exerted from its shear force against the wall of the house cause d the collapse of that part of the "independent structure".

You always have to look / take a glimpse at a chimney at any residential structure fire to see if its damaged or not. Its something that is often overlooked.

[post4031 16]

I agree, backdraft caused the collapse...

[nwpfd390 2]

thats why they have collapse zones

[lad12derff 283]

Ity appears as though they are using positive pressure to vent this structure. Look at the fan at the bottom of the stairs to the front door. It seems a little far away but it also may be a big a$$ fan. I'll stick with good old fashion venting because of crap like this.

[FFPCogs 863]

I would say a backdraft.

From my perspective it is a fire in the wall space around the chimney possibly caused by the extension of fire from flue or firebox, although I really can't tell if the chimney is involved. The heat and smoke follow the natural path upwards with most of the heat remaining confined within the wall space behind the chimney. I would bet the wall was opened to look for extension in that void space and they found some. The pressure built up from the confined fire coupled with the abundance of air circulating because of the PPV caused a backdraft in the wall when it was opened and resulting collapse of the chimney only.

Ity appears as though they are using positive pressure to vent this structure. Look at the fan at the bottom of the stairs to the front door. It seems a little far away but it also may be a big a$$ fan. I'll stick with good old fashion venting because of crap like this.

I agree 100%. Fire science 101 heat rises and fire seeks out oxygen. Release the heated gases and smoke from the highest point before introducing more oxygen. Better to pull it where you want than push it God knows where.

Cogs

[x129K 1,393]

SOOOO many utilize PPV as an alternative to traditional, more effective, and "safer" ventilation....it is sad..I cringe when I hear "get the fan!" early in a fire...

[FF31-126 3]

I wouldn't engage that fan into the attack without knowing where it is venting, otherwise...

[Guest alsfirefighter]

I would say that the resulting collapse of the chimney came from what appears to be a backdraft because of the acute overpressurization of the attic space.

Whether or not PPV contributed to this would be a good debate depending on what part of the country you are from. Air is air and you would have had to build up a fair amount of air pressure within the entire open parts of the structure before it would have any effect on that attic space. Not to mention that there are a large amount of departments whom utilize PPV during fire attack with great success and there doesn't seem to be people there bailing out of buildings all over the place. What I have come to find (and I have come from a department down south where PPV was prevalent and I still discuss its benefits and efficiencies) is that PPV still has many myths and opinions which are not entirely true which causes some to think that it is unsafe...much like nomex hoods were treated in the mid to late 80's in the northeast and sadly in many cases well into the 90's in some areas here in Westchester. Studies have shown that PPV does not...does not...contribute to fire growth...you are still pushing atmospheric air at the same percentage as the fire is burning...if not used properly it can contribute to fire spread as you are now causing a air current the closest you come to the fan. Growth and spread are 2 different things. There are also studies and I have seen this first hand myself that utilizing PPV during overhaul will not cause a rapid flare up of hot spots...it will cause an ember to smolder a bit more and if close to the fan where the velocity of the air current is highest may cause a small rekindle but not some wacky, crazy fire phenomenon. PPV is safe..but as with anything you need to know how to use it...you could quite easily have the similar event occur by simply taking the window..of overhauling...2 firefighters were lost in Ohio in this manner in the basement of a ranch a few years ago when overhauling after what was reported to be a small electrical fire with a light fixture.

Stay frosty....