chimney fire

[trouba]

I definitely would not burn until I had a professional inspection. Though you say the fire was outside the liner, I find it interesting that you had a quart of black, crispy creosote fall into the stove, thus suggesting it had to come from INSIDE the liner. Is it possible that the fire actually began in the liner and got the liner so hot that the exterior of the liner caught up what was left in the masonry flue?

I agree

Is there no top block off plate? I would think if there was a fire in the original chimney the smoke and fire would have no escape ( if you had a plate and you should ) and you would have more than some smoke in your house in fact you might not have a house. When I had my insert put in I had a sweep come in and clean the old clay chimney with one of those big cable whip cleaners. When he was done he said it was normal for a little creosote to fall down around the stove as the small amount that was left dried out and I should check and clean around my stove periodically. After 2 years nothing although the first year there was some. I think your fire was in your liner, and on a side note you can easily build up enough creosote for a big chimney fire in a month or 2 not fully seasoned wood and closed damper for long burns = creosote.

 

[gspro]

Well, if anyone knows any chimney guys around Western NY, let me know (35 miles south of Buffalo). I can't get anyone to come out (I shouldn't generalize, I only called 3 places). Not even getting return calls. I guess the masonry business is booming around here. Or, no one wants to deal with chimney fires.

 

[gspro]

Just a follow up. Had someone come out, seemed think that the creosote in the mortar joints and behind the flues ignited due to heat from the liner. Mandated that I double wrap the liner with wool insulation before he would consider it safe.
Rather than pull the liner double insulate it, and try to get it back down, what is the product that I can use to just dump down between the liner and the flue?

 

[mellow]

Vermiculite

HOW MUCH MIX DO I NEED ?

1) Multiply the inside dimensions of the chimney (in inches)
2) Subtract the area of the liner
3) Multiply this number by the chimney height (in feet)
4) Divide this number by 461, the answer is the number of bags you will need

One bag weighs 45 lbs and covers 2.5 cubic feet. Complete installation instructions.

 

[madrone]

I'd be concerned about any wooden structure next to the chimney. Any charring can significantly reduce the ignition point of the wood, from what I understand. Question for a pro.

 

[LeonMSPT]

Repeated sub ignition heating can reduce the ignition temperature of any combustible. Had a structure fire start under the fireplace in an old farmhouse one night... nearly destroyed the entire house. This "original" fireplace was there for as long as 100 years, as the tax documents and deed say "Age: 100+ years". They burned a fire in it one night, went to bed, it was burned down to coals. Woke up to smoke detectors going off and evacuated, called F.D. from next door. Good thing too, as the entire living room and kitchen were involved when we initiated the attack.

Investigation pointed to the flooring under the fireplace... (the bottom of the fireplace was mostly on the basement floor... little to no fire damage and no ignition source in the basement) with a SINGLE LAYER of brick between the fire and the oak flooring. (duh).

Putting a zero clearance liner in to replace the existing one would be smart. Not sure about the vermiculite, as there is no way to insure an equal distance between the liner and the wall of the existing flu. Have had a couple installers look at the floor and shake their heads about it... they've had to go back and remove it, and replace it, on a couple occasions. One guy nearly lost his house because there was a place where the liner had shifted over and was pushed against the side of the old flu. If you carefully placed and situated a rigid liner in the straight section of the flu, vermiculite would likely be okay, through the straight section of the flu.

A replacement zero clearance, insulated liner, installed carefully so as to not tear the insulation from the liner, is likely the safest practical way to do that job the safest. Just my opinion, based on what I've been able to learn over the last five or so years of being involved in the relining stuff on an "amateur" basis. In addition to what I've been able to glean after being involved in the fire service since 1984.

I'd be concerned about any wooden structure next to the chimney. Any charring can significantly reduce the ignition point of the wood, from what I understand. Question for a pro.

 

[LeonMSPT]

Description of the situation in the original post indicates a fire between the liner and the flu... definitely. Maybe a fire inside the SS liner as well. Maybe one started and ignited the other... might have been nearly simultaneous. An uninsulated flex liner can contact the flu at any or multiple points in the flu on the way to the top. With the blockoff plate at the top of the chimney, air travel is severely restricted, as it must draw from around it, through the masonry if it can, and from below... exhausts the same way. Had there been decent air travel between the SS liner and the flu, we'd be talking about a house fire... well after the fact probably unless the homeowner could borrow a computer and felt like he wanted to discuss it. Likely not for awhile afterward...

It's one reason why quite a few installers insist on insulted, zero clearance, installs.

I have a section of chimney connector pipe with "Elmer's Blanket" on it. Only 16 inches between it and a wood beam. I can put my hand on the insulation anywhere when it is up on high fire with a stack temperature of 425 degrees... just warm. Going to put a layer of it on the beam too, then hang a sheet steel heat shield from the stringers beside the beam in case something "really bad" happens...

When it comes to fire... "Always plan for something "really bad" to happen..." If you don't, it probably will. If you do, it will all be for nothing, but peace of mind is worth the time and a few bucks.

 

[gspro]

It's one reason why quite a few installers insist on insulted, zero clearance, installs.

what is a zero clearance install?

I've seen plenty of recommendations for the insulated liner, but none have recommended a double layer, unless that is implied?

 

[LeonMSPT]

Putting a liner in an older chimney flu that may not be the best in the first place. I'd put a zero clearance system in. The last one I did was rigid through the straight flu, and flex through the offset. When I set it up, my cousin, who provided the materials, sold me:

Twelve feet of 8 inch SS pipe, twelve feet of insulated "snap tight" SS overlay, a box of "Elmer's Blanket", stainless netting to protect and retain the soft blanket, and ten feet of flex pipe...

Laid it all out on the ground, fit it, and riveted it. Put snap tight insulation on. Sprayed with adhesive, and wrapped with blanket. Fitted stainless net, and pulled it tight. Took it up on the roof and stuck it down the chimney. Promptly got the flex jammed in the offset, and ruined it... tore it to hell trying to get it unstuck. Bought ten feet of flex from "Elmer" in Auburn, Maine. Rugged stuff...! Won't break that putting it in.

It's what the "pro" said to put, so it's what I put.

When I asked him about it, he said,

"Might have cleaned the chimney really good... but there is no knowing whether or not there is creosote someplace in a seam or glaze along the edge of the flu, corners... blah blah... liners commonly reach 1000 degrees during normal operation. If you just stick a liner in, or even a liner with a single layer of insulation on it. How do you KNOW it won't ignite creosote left in there? If I put a zero clearance system in, I KNOW there isn't going to be a fire between the liner and the chimney flu."

Over the years, they've had clients lose houses and have major damage done from this stuff. They don't take chances with it. If you can't afford to do it right, they won't do it. Happy to sell you what you want to do it, advice is free. But if he's doing the work, you're never going to be standing outside with red lights flashing in your face, cursing him.

The last one... new house, nearly a million dollars. Hundreds of thousands of dollars worth of damage... Cause? Insulation blown into the attic space, contacting the chimney full circumference. Insulation clearance spacer was installed, and blown full of insulation by the contractor who did the insulation.

Whose fault is that?

Send them to school, they eat the books.

It's one reason why quite a few installers insist on insulted, zero clearance, installs.

what is a zero clearance install?

I've seen plenty of recommendations for the insulated liner, but none have recommended a double layer, unless that is implied?

 

[gpcollen1]

It's one reason why quite a few installers insist on insulted, zero clearance, installs.

what is a zero clearance install?

I've seen plenty of recommendations for the insulated liner, but none have recommended a double layer, unless that is implied?

Duraliner is rigid double wall with insulation in between. I just installed 10 feet or so of that with the heavy duty flex through my damper to a tee to the back of my F400. I am sleeping good with that install except for I am going to put a screw or two through the brace and into the pipe on top of the chimney.