Got a night reminder last night.........

[tfdchief]

........to remind everyone to clean your chimney. TFD went to our first chimney fire of the season last night at 1 AM. This one needed a little more than cleaning. It was an old masonry chimney, very tall and in bad shape, no liner.

 

[BrowningBAR]

There are a lot of those folks in the PA area.

 

[firefighterjake]

And here's one in Maine that apparently caught the roof on fire . . . http://bangordailynews.com/2012/11/...ing-the-need-for-regular-chimney-maintenance/

 

[BrotherBart]

Cold and wet last night. First night so far that I heard the fire wagons make three runs.

 

[Sprinter]

'Tis the season. We could count on it every year.

 

[schlot]

Here is a question for firefighters. I would guess chimney fires are the most common reasons house fires start resulting from wood burning, is that what you see? Are there other common reasons, such as stove placed too close to walls, too close other flammables or open doors throwing sparks?

 

[Sprinter]

Here is a question for firefighters. I would guess chimney fires are the most common reasons house fires start resulting from wood burning, is that what you see? Are there other common reasons, such as stove placed too close to walls, too close other flammables or open doors throwing sparks?

Well, my experience is limited to my experience in an all-volunteer, largely rural department, but we didn't see too many extension fires from chimney fires. Probably different departments have different experiences and maybe there are statistics on this (I hope all that paperwork I had to do went for something useful).

It depended a lot on the type of setup (fireplace or stove, new or old, type of chimney, roof, etc). Older stoves or fireplaces and older chimneys were the worst, often because creosote buildup would be worse, and with no cap a chimney fire could extend to the roof easier. I don't recall an extension fire with a newer installation using a class A chimney.

But we had pretty decent response times for a volunteer outfit and I'd like to think that our fire prevention program was successful

In fact, we probably had more problems with other heating systems like baseboard heaters (ugh) or space heaters than wood burning.

<Note that bad, bad fires do result from all kinds of improper use, poor installations, etc>

 

[corey21]

I know a few chimneys around here that are a ticking time bomb.

 

[firefighterjake]

Here is a question for firefighters. I would guess chimney fires are the most common reasons house fires start resulting from wood burning, is that what you see? Are there other common reasons, such as stove placed too close to walls, too close other flammables or open doors throwing sparks?

Well . . . yes and no . . . in terms of sheer numbers of woodstove related fires I would guess that we see quite a few chimney fires . . . but most do not extend beyond the chimney in most cases although as noted from the fire in Bath they can and have spread which is why they are nothing to just disregard or think as normal.

I would guess that in terms of more serious fires (i.e. more property damage) it's a toss up between the improper disposal of the ashes (i.e. putting them in cardboard box and sticking them on the wooden deck) and combustibles too close to the stove.

In terms of serious injuries . . . seems like every year we get a few folks who think starting their woodstoves with gasoline or other flammable liquids in a small, confined space is a good idea.

 

[schlot]

Well . . . yes and no . . . in terms of sheer numbers of woodstove related fires I would guess that we see quite a few chimney fires . . . but most do not extend beyond the chimney in most cases although as noted from the fire in Bath they can and have spread which is why they are nothing to just disregard or think as normal.

I would guess that in terms of more serious fires (i.e. more property damage) it's a toss up between the improper disposal of the ashes (i.e. putting them in cardboard box and sticking them on the wooden deck) and combustibles too close to the stove.

In terms of serious injuries . . . seems like every year we get a few folks who think starting their woodstoves with gasoline or other flammable liquids in a small, confined space is a good idea.

Are you saying it's not????

When you say combustibles, is it usually "Stuff" placed close too the stove or the stove placed too close to the wall?

 

[jeff_t]

In 20ish years with a mostly rural, paid on call department, I recall exactly one serious fire directly related to a wood burning appliance. It was, in fact, an OWB . Embers out of the pipe on a windy night blew up under the eaves and burned off the second floor.

Not many wood burners around here, and the few chimney fires that happen usually don't extend to the structure. I can think of a couple, but the damage was minimal.

 

[firefighterjake]

Are you saying it's not???? Yes . . . assuming you know that this is a bad idea . . . and a very, very bad idea when it comes to gasoline.

When you say combustibles, is it usually "Stuff" placed close too the stove or the stove placed too close to the wall? Usually stuff placed too close to the stove . . . wood, chainsaw, kindling and as we saw recently cardboard . . . occasionally there is the stove placed too close to the wall.

 

[schlot]

Yes I do...funny thing is I was giving some advice to a friend who has a fireplace in his house on how to start a fire. I made sure he knew not to use gas, etc...at first I thought "who would do that inside a house"...but seeing your post, I guess there are people who think it's ok.

 

[tfdchief]

Here is a question for firefighters. I would guess chimney fires are the most common reasons house fires start resulting from wood burning, is that what you see? Are there other common reasons, such as stove placed too close to walls, too close other flammables or open doors throwing sparks?

We seldom see chimney fires extend past the chimney. Most wood burning related fires around here that do extend past the chimney or appliance seem to be from improper installation. Or, old fireplace chimneys being used for an insert and not having proper clearance to combustibles. It worked as an occasional fire place fire, but not as a 24/7 wood burning insert or wood stove. The last one was a 100 year old plus fireplace and chimney with an insert in it. They had lined the chimney (not insulated) but the clearance of the wood framing was not adequate and it finally got the framing charred enough one night to catch.

 

[corey21]

I have a question.

Is it true that takes a heavy amount of creosote to cause a real intense chimney fire?

 

[tfdchief]

I have a question.

Is it true that takes a heavy amount of creosote to cause a real intense chimney fire?

Well, I guess there is no way to know for sure how much creosote there was before the chimney fire, but I can tell you that I have seen some pretty tame ones and some that rivaled a jet engine. So I would say that for sure a heavy amount is going to be much more of a problem. Creosote expands when it burns. Sometimes I have seen it completely close off the chimney.

 

[corey21]

Well, I guess there is no way to know for sure how much creosote there was before the chimney fire, but I can tell you that I have seen some pretty tame ones and some that rivaled a jet engine. So I would say that for sure a heavy amount is going to be much more of a problem. Creosote expands when it burns. Sometimes I have seen it completely close off the chimney.

I am glad i sweep my pipe once a year and try to keep my system up to temps.

I read a study were a guy smoldered a fire for 2 weeks just to study a chimney fire he had a gas temp of 150F to make the soot. Then when it caught fire it hit 2400F

 

[bag of hammers]

We seldom see chimney fires extend past the chimney. Most wood burning related fires around here that do extend past the chimney or appliance seem to be from improper installation. Or, old fireplace chimneys being used for an insert and not having proper clearance to combustibles. It worked as an occasional fire place fire, but not as a 24/7 wood burning insert or wood stove. The last one was a 100 year old plus fireplace and chimney with an insert in it. They had lined the chimney (not insulated) but the clearance of the wood framing was not adequate and it finally got the framing charred enough one night to catch.

Is liner insulation intended to keep the chimney warm (prevent condesation etc) or to protect the surrounding materials in the event of a chimney fire? Or both? Does it add a lot more expense? Sorry I don't know much about liners but curious why they're not required as they seem to make the install so much safer...?

 

[tfdchief]

I am glad i sweep my pipe once a year and try to keep my system up to temps.

There is no question it takes fuel to have a fire. So, if the chimney is clean, there is nothing to burn. Keep the fuel and the fire in the fire box that is designed to have a fire.

 

[James02]

Here is a question for firefighters. I would guess chimney fires are the most common reasons house fires start resulting from wood burning, is that what you see? Are there other common reasons, such as stove placed too close to walls, too close other flammables or open doors throwing sparks?

We had a probie a few years ago (he was a truckie, sorry guys!) use a water can on a stove that took off, cracked the stove...But the wall was fairly warm also....

 

[Ashful]

Is liner insulation intended to keep the chimney warm (prevent condesation etc) or to protect the surrounding materials in the event of a chimney fire? Or both? Does it add a lot more expense? Sorry I don't know much about liners but curious why they're not required as they seem to make the install so much safer...?

Both, and it does not seem to add that much expense. I've insulated half the flues on this old house, using both insulated (wood appliances) and un-insulated (oil appliances), but always being different lengths and conditions (thimbles, etc.), it's hard to compare price directly:

44' un-insulated 6" rigid tube with cap and collar, and thimble to basement oil furnace: $1300 in 2001
22' un-insulated 6" flex with cap and collar, and thimble to basement oil furnace: $1795 in 2011 (actually I paid less than this, that was the higher of the two quotes I received, can't remember the amount I actually paid)
23' insulated 6" smooth-wall flex with block-off plate for wood stove on 50' high, steep, standing-seam metal roof with enormous flag-stone chimney top in the way: $2400 in 2011
13' insulated 6" smooth-wall flex for woodstove, slid into existing 8" round clay tile, reusing existing block-off plate and cap, $1100 in 2011

The smooth-wall flex was a $200 - $250 mark-up above standard flex (installer quoted both ways), but I never asked the price difference to do the wood appliances with un-insulated. I knew I wanted insulation to help with my draft on the 13' flue, and to avoid creosote build-up in the 23' flue.

 

[Ashful]

We had a probie a few years ago (he was a truckie, sorry guys!) use a water can on a stove that took off, cracked the stove...But the wall was fairly warm also....

Can you just shoot a fire extinguisher into a flaming chimney? Seems to me that's the first thing I'd be reaching for, if I had a chimney fire at my house.

 

[firefighterjake]

Can you just shoot a fire extinguisher into a flaming chimney? Seems to me that's the first thing I'd be reaching for, if I had a chimney fire at my house.

Yes . . . one "trick" we have done for years . . . actually two "tricks" (maybe I should call them "techniques") is to drop pre-filled Ziplock baggies full of ABC dry chemical powder down the chimney if it is on fire . . . and since many of the homes that have chimney fires often do not have metal liners and are in masonry chimneys we sometimes can open up the clean out door and then sprinkle some water on to any hot creosote that has fallen down into the clean out area . . . water turns to steam, steam expands and rises on the draft and can put out the fire.

I should perhaps point out the obvious to folks . . . it is far better to not have a chimney fire. Burn well seasoned wood. Burn at the proper temps (not too cool and not too hot). Check and clean your chimney on a regular basis.

 

[brian89gp]

Does insulating a chimney liner that is installed in a masonry chimney help much with the heat transfer to nearby combustables?

I have an inside chimney, insulated flex lined, and have checked the surface temp and it seems to rarely get above 100*

 

[Ashful]

I should perhaps point out the obvious to folks . . . it is far better to not have a chimney fire. Burn well seasoned wood. Burn at the proper temps (not too cool and not too hot). Check and clean your chimney on a regular basis.

Yep... that's the obvious, but it's good to know what to do in the "what-if" scenario. How about opening the bypass damper, opening the front doors of the stove, and shooting an ABC extinguisher right on the fire and then directly up the chimney? Again, I suspect that would be my first inclination, should a chimney fire ever occur. Digging a ladder out of the barn, trucking it down to the house, setting it up and climbing to the top of a flaming chimney might not be my first choice!

Does insulating a chimney liner that is installed in a masonry chimney help much with the heat transfer to nearby combustables?

Yes, and this is why they're required any time you have a zero-clearance issue between the masonry chimney and combustables, such as roof rafters or sheathing touching your masonry stack.