Speaking of chimney fires…

[Mr. Kelly]

There was a house in an adjacent neighborhood that burned nearly to the ground awhile back. Report in the newspaper said that the fire started with a woodstove. According to the report, embers from the fire "caused nearby wood beams to ignite."

How would this happen? We have triple wall steel pipe in our house. Is it a matter of a pipe getting too hot? Or, maybe this was an actual brick chimney with masonry gaps?

Not really sure if a triple wall pipe would be capable of this kind of result?

Makes me a little nervous, given that I leave a fire going every time I walk upstairs to go to sleep!

Any thoughts or comments would be appreciated!

 

[begreen]

Hard to say with such a minimal description. It would just be speculation. Were they running the stove with the door open?

 

[Mr. Kelly]

Sorry…! I forgot a pertinent detail...

The article said that the embers were in the chimney.

I know this is not much to go on, but still interested in how chimney fires can cause housefires.

 

[bholler]

Could have been lack of proper clearance or any number of things

Not really sure if a triple wall pipe would be capable of this kind of result?

If it is in good repair and all clearances are honored then the chances of it happening are very slim

 

[Jo191145]

First you need to take any newspaper article with a grain of salt. Sure a woodstove was involved but getting to the exact cause from an inspector that may not know then written by a reporter that knows even less is not reliable.

In my expierience most masonry chimney fires resulting in house fires begin with wet wood. Creosote in the chimney can be built up through improper use and ignite. We all know that here. Nine times out of ten that's not enough to burn the house down. Severely wet wood leaves all that moisture inside a chimney mixing with creosote creating a black water that runs down the flue looking for cracks that normally wouldn't be all that dangerous. The black water mixture collects over time and can even make it's way to the interior framing, pooling, drying and hardening. Now when the day comes the owner gets a chimney fire there's all these pockets of congealed napalm just waiting for enough heat to set them all off. That's how you burn down a house with a chimney fire IMO.

 

[Chuck the Canuck]

maybe some embers from the chimney fire ignited the roof?

 

[Jo191145]

maybe some embers from the chimney fire ignited the roof?

Always possible, especially if your roof looks like this.
https://www.hearth.com/talk/threads/my-neighbors-photo-of-chimney.139501/

 

[kennyp2339]

In a masonry flu the high heat from the chimney fire cracks the flu tiles, the mortar joints crack on the outside of the chimney making a small gap which flames go through and ignite any exposed wood in the house. I have been to many chimney fires and usually the first fire is no big deal, its when the homeowner does not get the chimney inspected / cleaned and does not change burning practices that the second fire is "the big one" because the cracks already formed from the first fire. Also when I arrive at a chimney fire the first thing I look at is the attic area, that usually is the area to catch fire first, that's the area were most creosote tends to collect, the upper portions of the chimney.

 

[Warm_in_NH]

Being skeptical of everything in this house. We decided to rip out the hearth and chimney that my wife had been burning with for 5 years.
Photos are elsewhere on here, but long and short of it, there was a clear crack in the thimble that led directly to dry hay and leaves packed directly against it by squirrels prior to her moving in. There was actually evidence of scorched hay against the thimble in the wall.
How it didn't burn the house down is beyond me. Very thankful we re did it this year and now know it is all good.

 

[Jo191145]

Being skeptical of everything in this house. We decided to rip out the hearth and chimney that my wife had been burning with for 5 years.
Photos are elsewhere on here, but long and short of it, there was a clear crack in the thimble that led directly to dry hay and leaves packed directly against it by squirrels prior to her moving in. There was actually evidence of scorched hay against the thimble in the wall.
How it didn't burn the house down is beyond me. Very thankful we re did it this year and now know it is all good.

There's supposed to be masonry surrounding that thimble and your stove pipe should always project inside to the flue so the thimble is subjected to heat but not actual fire.

 

[begreen]

Yes, there needs to be 12" of masonry to the nearest combustible including the wood framing. However, the flue pipe should not project into the chimney. It should be flush with the inside liner.

https://www.hearth.com/econtent/index.php/articles/passing_a_chimney

 

[NinjaTech]

As far s the original posters concern, if the wood stove was the cause of the fire it was probably due to either an improper installation that was against code, lack of proper maintenance, or operator error. As long as your equipment is setup properly and to code, and you maintain and run it safely you shouldn't have to worry. If you do have any concerns about your setup, have it inspected by a reputable certified sweep.

 

[Warm_in_NH]

There's supposed to be masonry surrounding that thimble and your stove pipe should always project inside to the flue so the thimble is subjected to heat but not actual fire.

Yep. It's the wife's house. She had a stove going here before we got together. Got me to buy a stove and install it in my house in NH after seeing how nice the heat from it was. During my install, I found Hearth.com and learned a TON of info, and continue to learn.
As time went on and I started doing projects on the circa 1850 house, as a contractor, I started to see how many corners were cut by previous owners. Bad electrical, bad plumbing, bad carpentry, you name it, they found a way to do it wrong. That, combined with my new found knowledge on here over the past couple years, and her dislike for the brick hearth, is what prompted me to dig into things and take a look around.
It was sleeved with stove pipe on the inside, but hadn't always been, the mortar was gone around most of it, the debris by the crack was charred, but appeared to have snuffed itself out due to a lack of oxygen, maybe from due to the fiberglass insulation that was also stuffed in where the mortar was missing.

She always swept the flue herself so a pro never laid eyes on it, scary.

Long and short, this is what I think of when people say they don't understand how a stove can burn a house down.

 

[begreen]

There are often all sorts of short cuts and nightmares buried behind walls. The more remodels the more likely this it to be true.

 

[bholler]

There's supposed to be masonry surrounding that thimble and your stove pipe should always project inside to the flue so the thimble is subjected to heat but not actual fire.

Yes there should be but I rarely see it done correctly From what i have seen chimney fires that start house fires usually either start at the wall pass thru or just from heat transfer to wood that has gone through pyrolysis for many years and with this fire it got hot enough to ignite. That is why i always stress the importance of insulation.