Chimney fire while using my Fireview

[CTburning]

I have been burning for five years now and have heard of several chimney fires but never thought I would have one. My setup is a Fireview in the basement of a ranch home. 16 Feet of triple wall chimney (8†inside diameter) along the outside of the house connected to a rise of another 2-3 feet of single wall inside. I burn dry wood, stacked and seasoned for two years and future years will be closer to three. Unfortunately I burn mostly Red Oak, and I’ve had a couple of pieces sizzle. This was my second year burning with the Fireview and I didn’t have much creosote last year. My plan was to inspect and sweep the chimney towards the end of January but because of the snow this year, skipped that ritual.

My three cords only lasted until the beginning of March but my girl hates the cold so under pressure from her I burned some marginal at best Swamp Maple that I was going to use next year. Some of the pieces hissed a bunch and a couple had water sizzle out the ends but the majority of the pieces burned quick but hot.

The last Sunday of March I was cutting up some rounds at the far end of my property and I noticed a big puff of smoke come from the chimney. I thought it was a little odd since the stove was winding down and the stove top shouldn’t have been much over 300 or so. I finished up and a couple of minutes later walked down and went to check out the stove. The moment I walked into the basement room I got a strong leaf burning smell. Stove was 250-300, I don’t recall the specifics but it was definitely cooled down and only had coals left. I went outside and found ashes all around the triple wall and the ground was steaming/smoking. It didn’t take but a half gallon of water to put it out but a rock beneath the surface of the ground was too hot to touch.

I grabbed my welders glove that I use for the stove and removed the ashes and mulch. I found ashes under the bottom of the chimney and to the right hand side of the chimney for a distance of 3 feet or so. The wind blows leaves up against the side of the house and I’m guessing it must have built up under and to the side of the chimney. The pipe was warm to the touch at first but was cold an hour later. The next day when I hopped on the roof and ran the brush down, I had some creosote at the cap but not much down below. I dug out under the pipe and with just my hands was able to take the bottom plug off without any tools. The pipe sits about two inches off the ground and I’m assuming was held in place with the loose rocks/gravel that I removed. The plug was almost filled to the top with creosote that I had brushed, about 2 inches worth.

Since my foundation is concrete, the fire had gone out on its own and was fueled by a pile of leaves but it is scary to think that something I had total confidence in (my outside chimney) failed. I am seriously considering a second stove for the upstairs and will be visiting a local stove shop to discuss an insert for my fireplace and I will show the installer the plug. I felt the bottom of the pipe and can feel a couple of nails sticking through so it will be hard to get the plug back in there securely (which explains the rocks, the previous owners jury rigged everything). I might have to dig a hole underneath to get a better peak. I am assuming that the plug has been out before because as soon as I removed some of the gravel, I was able to wiggle it out of there. I’m assuming that’s not the way its supposed to be. Any one have any experience with these types of chimneys?
I have already come up with a solution, put a 6†liner in. I had considered putting one in already but was holding off because the Fireview cruises easily at 500-550. I can overheat the 425 sq ft finished part of the basement but only keeps the upstairs in the low 60’s. I still want to do a review of the Fireview but that is for another post. Sorry for the long story but I thought I’d share in case anybody else has a similar situation.

 

[pen]

Sorry to hear of your problem but glad to hear the result is your house and family are OK.

How well did that plug seal? I'm wondering if you had an air leak there which would help promote cooling and creosote production for you.

Also, I'd find the manufacturer of that pipe and check the clearances and make sure your install meets them. It's tough to tell from the picture but it doesn't look like there is much clearance from that thimble as it goes through the old window.

pen

 

[jeff_t]

Not sure how you would get a liner in there with the T, but I don't know much about liners. If it was me, I'd start over with a new chimney. Done the right way. It's not something you can jury rig.

 

[begreen]

Thanks for posting CT. I'm glad this didn't turn out to be a more serious event.

There are some good lessons here. The first being the importance of burning dry wood. The second being, that when you inherit a flue system, inspect it very closely or better yet, have a certified sweep inspect it for safety, condition, and integrity. The third being, if the wood is not very dry, clean much more frequently. The fourth being, if you have a ground level flue connection, keep it debris free.

 

[Backwoods Savage]

For sure that is a bad chimney setup. Second problem is burning red oak only 2 years seasoned. We always give it 3 year as that is the slowest drying wood we have. It was probably a combination of the fuel and the way the chimney is that caused the creosote. Also, having the chimney right at ground level is for sure asking for problems. It is great that it worked out okay in the end though.

 

[Slow1]

You sure you had a 'real' chimney fire there? What I mean is are you sure you actually were burning a fire inside the chimney itself that was ignited by your stove? It sounds like there is a good chance you had some burning going on under/around the 'plug' of that clean out. It seems plauseable to me that you could well have simply had enough heat build up around there to ignite the leaves/sticks/whatever was built up around there and that could have been burning away. If not sealed well around the plug perhaps the chimney was involved as well - perhaps even providing a draft to the fuel in the hole (sort of a mini rocket stove effect?).

In any case, whatever happened there, I would make sure that your chimney system is right before burning again. I don't believe that you should have anything flammable pushed up against that chimney at any time and the clean out cap should hold itself in (I believe most twist/screw in) and seal up well. Naturally all clearances should be checked...

 

[CTburning]

You sure you had a 'real' chimney fire there? What I mean is are you sure you actually were burning a fire inside the chimney itself that was ignited by your stove? It sounds like there is a good chance you had some burning going on under/around the 'plug' of that clean out. It seems plauseable to me that you could well have simply had enough heat build up around there to ignite the leaves/sticks/whatever was built up around there and that could have been burning away. If not sealed well around the plug perhaps the chimney was involved as well - perhaps even providing a draft to the fuel in the hole (sort of a mini rocket stove effect?).

In any case, whatever happened there, I would make sure that your chimney system is right before burning again. I don't believe that you should have anything flammable pushed up against that chimney at any time and the clean out cap should hold itself in (I believe most twist/screw in) and seal up well. Naturally all clearances should be checked...

I'm not positive that I had a real chimney fire because of the way the events transpired. The stove was running on fumes at around 300 stove top so I can't imagine a metal outside chimney being too hot on a 50 degree windy day. The reason I assume I had a chimney fire is because the fire started out around the bottom of the outside chimney. I may be wrong in assuming that it would take a small chimney fire on the bottom of the tee to produce enough heat to ignite dry leaves in a windy location. I would think that during reload or shortly thereafter the chimney would get to its hottest temperature and not 5 hours later.

I am not sure how well the plug was fit into the base. It seemed like a paint can type pitting as there are not threads. I'm assuming it was just pushed into place and small rocks/gravel was placed underneath to hold it there. AFter the fire I went on the chimney and ran the brush through it. I looked down and 90% of the creosote was up around the cap. After running the brush through I pulled the plug and it had around 2 inches or so of creosote in it.

My theory was that some of the creosote and fallen down into the tee and ignited which caused the plug to leak enough heat to ignite the leaves surrounding the cleanout. A top down fire if you will. I was burning wet wood in March which I"m sure created extra creosote. I'm thinking about installing a second stove upstairs so I will get an installer or sweep to check out my setups and determine if everything is safe.

 

[Slow1]

My theory was that some of the creosote and fallen down into the tee and ignited which caused the plug to leak enough heat to ignite the leaves surrounding the cleanout. A top down fire if you will. I was burning wet wood in March which I"m sure created extra creosote. I'm thinking about installing a second stove upstairs so I will get an installer or sweep to check out my setups and determine if everything is safe.

There too is part of my confusion - my understanding (based on reading here mostly) is that a chimney fire tends to consume all the creosote rather well. Thus had you actually had it burning in the pipe you would not likely had anything left to find down there in the clean out. I'm far from an expert here.

However, I have also read about long smoldering fires in leaves etc that can go on literally days before "breaking out" and showing enough smoke/flame to be noticed. Thus I do wonder if perhaps over weeks your leaves and sticks slowly warmed up and dried out down there until they finally got dry enough to light off just that little bit (perhaps during that startup/reload) and took 5 hours to finally build up enough to be noticed?

Likely you may never really know... I'd love to hear from those with actual training here (FF Jake where are you?) to perhaps invalidate/confirm the theories I'm tossing around here - I may be onto something or totally off base after all.

 

[CTburning]

There too is part of my confusion - my understanding (based on reading here mostly) is that a chimney fire tends to consume all the creosote rather well. Thus had you actually had it burning in the pipe you would not likely had anything left to find down there in the clean out.

To clarify, I ran the brush down the chimney and then removed the plug in the bottom of the cleanout. I am assuming there was nothing in the cleanout before I cleaned the chimney and any evidence of burnt creosote got mixed in with what was in the chimney when I cleaned it. You could be right on with your theory of the leaves packup up against the chimney slowly getting dried out and eventually reaching ignition. I'm going to run it by the fire marshall when I stop by my local Fire Department to discuss the legalities and safe distance that a firepit should be from the house.

 

[fire_man]

Slow1 beat me to some good comments, so call me Slower1 for now. I agree with Eric, the leaves were probably smoldering for quite some time before finally igniting. And I am also not convinced the fire was internal to the chimney. Flue temps in the fireview are normally pretty low except for the first few minutes of firing things up.

What's your cap look like - is there a screen? Is it possible the fire simply started when you first fired up the stove and newspaper particles ignited the leaves below? What did you use to start the fire , paper or firestarters?

 

[CTburning]

Slow1 beat me to some good comments, so call me Slower1 for now. I agree with Eric, the leaves were probably smoldering for quite some time before finally igniting. And I am also not convinced the fire was internal to the chimney. Flue temps in the fireview are normally pretty low except for the first few minutes of firing things up.

What's your cap look like - is there a screen? Is it possible the fire simply started when you first fired up the stove and newspaper particles ignited the leaves below? What did you use to start the fire , paper or firestarters?

Firemans and Slow1's theory that the fire started from the leaves around the base of the chimney is probably right. It's what I first thought. What baffles me is how cool the chimney was and how late in the burn the fire started. The stove top was barely 300 and just running off the cat on coals. This happened a month ago and I can't remember if I threw in a piece of paper or two to get the first restarted in the late morning. My usual routine is to throw a small piece of swamp maple on the coals and get it burning hot and then load it up and get it to temp/burn off the moisture. I rarely use newspaper but might have on that occasion if there were less coals than usual.

There is a thicker wire metal screen on the cap and it did have creosote on it. I shook it off and brushed the chimney and ended up with a pint of so of creosote in the bottom of the plug. I'm going to have it inspected and lined or whatever other measure that they come up with. I'm also seriously considering ripping out the useless zero clearance fireplace and chimney upstairs and installing another stove (probably a keystone or fireview) so I'll have him check that out as well and tell me what type of pipe I have.

 

[begreen]

If you are going to continue to use this chimney, I would directly address potential future problems now. First, what is the clearance to the first level of siding from the top of thimble going though the basement window? It must be 2" or greater. Second, I would create a removable leaf screen out of 1/4" galvanized or stainless hardware cloth to prevent any leaf build up within say 6" of the pipe.