Creosote help please

[muchogrande]

Hi, I'm taking care of my father-in-laws house which is heated by a wood burning furnace. One morning I was having trouble getting the furnace started, and added a large chunk of cardboard and lit it on fire. The cardboard burned, and soon after I heard a WHOOSH like a jet engine coming from the chimney. Through a tiny crack where the metal pipe from the furnace attaches to the cinderblock chimney I could see flames inside the cinderblock chimney. My wife raced outside and saw black smoke billowing from the chimney. Thankfully, after closing the damper, the fire went out.

Later, after a couple scotches, I inspected the chimney base. There is a small metal door that I could open and look up the chimney as well as see into the metal pipe that connects to the furnace (on the left). Here is what I saw:


This stuff flakes off easily, but beneath it is a very shiny thin layer of black. I can't reach it tho so don't know if it is sticky or how thick it is.

Went up on the roof and looked down the chimney, this is what I saw:



The black stuff pictured is shiny and sticky to the touch - it has the consistency of tar. It coats the masonry liner as far as I can see down. The coating is about 1-5mm thick thick (where it has not bubbled),

All I know about creosite I have learned researching online after this event. From what I've read I assume this is stage 3. So out of fear of starting another chimney fire we have have stopped using the wood furnace and are heating the house with electricity (it has both).

I'm not sure where to go from here, so I'm looking for opinions. I have found a variety of products that claim to break stage 3 down but I don't know if we're at a point where those would do any good? Do we need a pro? Any help greatly appreciated.

 

[firefighterjake]

My advice . . . get a professional, certified chimney sweep to come in . . . and educate your father in law about burning seasoned wood, burning at the proper temps and doing frequent checks/cleaning.

Normally I would say . . . If money is tight, you may try burning one of those anti-creosote logs which supposedly helps turn the sticky, tarry creosote into something that can be more easily brushed . . . but those are not a substitute for actual sweeping. Now I said NORMALLY . . . in this case however with the amount of cresote I am seeing I would be quite leery of burning anything in that woodstove right now until the chimney gets swept . . . by you or a pro.

 

[Sconnie Burner]

Professional cleaning is definitely recommended at the point its at! No way of dropping anything down in to clean it. He needs to start using WAY dryer wood.
How lond since last sweeping? When was the wood cut and split?

Whether he buys or cuts his own he should be starting to think about at least having a 2 if not 3 year rotation of dry wood and you will never see that again! He can keep using what he has now but should be checking and cleaning the chimney every 2-3 weeks at most.

 

[jetsam]

Holy cow. Call the fire department before you light that thing up again, lotta fuel in that rocket.

In all seriousness, disconnect the flue pipe, grab his brush, and see if you can sweep it out. If he doesn't have a chimney brush, you have located one of the main problems.

 

[BradleyW]

Yikes. That needs some professional attention, and your father-in-law has a lot to learn about using his wood furnace.

 

[Nick Mystic]

This is a good example of why you should never burn cardboard in a woodstove/fireplace, etc. It is an excellent fire starter for chimney fires. As the burning paper releases from the cardboard surface it shoots right up the flue igniting the creosote when it get snagged along the way. It is also a good example of how easy it is for someone trying to operate an unfamiliar stove can get into trouble in a hurry. I'm not trying to unload on the OP, just using his story as a teaching tool for new wood burners.

 

[bholler]

yeah you need a pro for sure. And the cleaning is not going to be cheap. Taking care of that mess is going to take at least 4 hours. compared to a normal 30 min cleaning. And I would bet that after it is cleaned the sweep is going to find some clay tiles that are in pretty bad shape and recommend a liner. And by the way you did nothing wrong the condition of that chimney was the problem not your actions. I can guarantee that was not the first fire in that chimney.

 

[moresnow]

Those pics ought to be pinned as examples.

 

[bholler]

Those pics ought to be pinned as examples.

The sad part is that it is not that uncommon we see a fair number like that every year.

 

[jetsam]

yeah you need a pro for sure. And the cleaning is not going to be cheap. Taking care of that mess is going to take at least 4 hours. compared to a normal 30 min cleaning. And I would bet that after it is cleaned the sweep is going to find some clay tiles that are in pretty bad shape and recommend a liner. And by the way you did nothing wrong the condition of that chimney was the problem not your actions. I can guarantee that was not the first fire in that chimney.

Most of us see one or two chimneys a year; bholler sees a few more, so he generally knows what he's talking about.

 

[muchogrande]

Thanks for all the feedback, much appreciated. My wife said that they did have a chimney fire about 17 years ago which was extinguished by pouring sand down the chimney, but that was the only other time. Otherwise, my father-in-law has been using this furnace steadily to heat the house for the past 40 years without incident. The firewood is seasoned for a year minimum.

To confirm that the creosote wasn't going to come off easy, I went up and swept down the chimney a little with the wire chimney sweeping brush that he uses. I was able to dislodge some of the creosote. The removal of the big grey bubble obstructing the chimney is the most visible difference from the "before" photo at the top of the post. Here is what was left after i swept up and down about 5 times:



It is a little goey to the touch, but very hard. I could barely scrape any off using my finger.

From what you all have said, my inclination is to recommend getting a professional to clean this out. From what I understand, if the liner has been compromised and creosote is leaking through, that can create the opportunity for a chimney fire to spread into the house. So like you say bholler, the liner should be inspected and perhaps a metal liner installed.

That sound right?

 

[edthesweep]

Thanks for all the feedback, much appreciated. My wife said that they did have a chimney fire about 17 years ago which was extinguished by pouring sand down the chimney, but that was the only other time. Otherwise, my father-in-law has been using this furnace steadily to heat the house for the past 40 years without incident. The firewood is seasoned for a year minimum.

To confirm that the creosote wasn't going to come off easy, I went up and swept down the chimney a little with the wire chimney sweeping brush that he uses. I was able to dislodge some of the creosote. The removal of the big grey bubble obstructing the chimney is the most visible difference from the "before" photo at the top of the post. Here is what was left after i swept up and down about 5 times:

View attachment 190706 View attachment 190707

It is a little goey to the touch, but very hard. I could barely scrape any off using my finger.

From what you all have said, my inclination is to recommend getting a professional to clean this out. From what I understand, if the liner has been compromised and creosote is leaking through, that can create the opportunity for a chimney fire to spread into the house. So like you say bholler, the liner should be inspected and perhaps a metal liner installed.

That sound right?

Yep, I have been a sweep my entire life and Id say your best bet is breaking out those tiles and s.s. reline.
Other options are chemical cleaning or mechanical for the third stage creosote but i bet you find damaged tiles and need to reline anyway. was size (diameter) pipe coming off stove? how tall chimney?

 

[edthesweep]

**EDIT:what* size (diameter) is the stove pipe?*

 

[muchogrande]

Diameter of the metal pipe that connects the furnace to the chimney is about 6 inches. Chimney height is approx 26 feet (that is from basement floor through 1 story vaulted ceiling log house to roof). The metal pipe from the stove connects to the cinderblock chimney about 5.5 feet above the basement floor, so from that connection to the top of the chimney would be about 20 feet.

 

[bholler]

My wife said that they did have a chimney fire about 17 years ago which was extinguished by pouring sand down the chimney, but that was the only other time. Otherwise, my father-in-law has been using this furnace steadily to heat the house for the past 40 years without incident. The firewood is seasoned for a year minimum.

I can guarantee they have had allot more chimney fires than that. They may not have known it but there is no way they could possibly burn in a chimney that looks like that and only have 2 fires in 40 years. I agree with ed's statement I would probably not even try cleaning that Just break it all out and reline.

 

[edthesweep]

Diameter of the metal pipe that connects the furnace to the chimney is about 6 inches. Chimney height is approx 26 feet (that is from basement floor through 1 story vaulted ceiling log house to roof). The metal pipe from the stove connects to the cinderblock chimney about 5.5 feet above the basement floor, so from that connection to the top of the chimney would be about 20 feet.

oK. iN that case you wont need to break out the tiles to install a six inch liner(unless you want to insulate it) , I would mechanical or chemically clean it and then install six inch ss liner. the ss liner will also come clean much easier - that third stage creosote doesn't really cling to it the way it bakes into the terracotta tile.

Let me know if you have any questions about how to do it or what it should cost

 

[edthesweep]

oK. iN that case you wont need to break out the tiles to install a six inch liner(unless you want to insulate it) , I would mechanical or chemically clean it and then install six inch ss liner. the ss liner will also come clean much easier - that third stage creosote doesn't really cling to it the way it bakes into the terracotta tile.

Let me know if you have any questions about how to do it or what it should cost

Poultice creosote remover is the chemical cleaner I'd use - they have an awesome video on youtube.and it really works like that!