Help with a stove pipe repair

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tightxstack

Member
Nov 10, 2016
3
Earth
Last winter a heavy snow slid off the roof of my guest cabin (friends & family only :)) and tore off the stove pipe. After all these years, it got taken out. I patched the roof and am now trying to source replacement stove pipe pieces, and I could use some help with identifying the specific pieces I need. I live >2 hours from any stores that carry this stuff so I would like to shop with advance knowledge of what I need and return home with all the right pieces. I do not want to remove the stack support piece that is in the ceiling. This stove will not ever be used on a regular basis, but I need it to be functional. As you can see from the pics, everything's 'good enough' up to the elbow that enters the chimney support box. I'd like help identifying the pieces I need to run up thru that box and get up to my cap. The damaged piece I removed had a flange at the bottom, which I think attached to the inside of the support box. This ran through the roof and joined another piece of single wall, then the cap. There was also a storm collar, and another piece that had a big flange that slid under the roofing metal. I've seen the storm collars and the roof flashing at the big box stores. What has eluded me is the piece I need to go from that elbow inside my cabin up through the roof. I would love to get this completed before the snow flies (October 31), and I've finally got time to begin my research. And I'm damn sure going to install one of those vee shaped snow guards on my roof. Thanks!

wood stove.jpg wood stove 2.jpg stove detail.jpg roof patch job.jpg
 
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bholler

Chimney sweep
Staff member
Jan 14, 2014
25,020
central pa
Last winter a heavy snow slid off the roof of my guest cabin (friends & family only :)) and tore off the stove pipe. After all these years, it got taken out. I patched the roof and am now trying to source replacement stove pipe pieces, and I could use some help with identifying the specific pieces I need. I live >2 hours from any stores that carry this stuff so I would like to shop with advance knowledge of what I need and return home with all the right pieces. I do not want to remove the stack support piece that is in the ceiling. This stove will not ever be used on a regular basis, but I need it to be functional. As you can see from the pics, everything's 'good enough' up to the elbow that enters the chimney support box. I'd like help identifying the pieces I need to run up thru that box and get up to my cap. The damaged piece I removed had a flange at the bottom, which I think attached to the inside of the support box. This ran through the roof and joined another piece of single wall, then the cap. There was also a storm collar, and another piece that had a big flange that slid under the roofing metal. I've seen the storm collars and the roof flashing at the big box stores. What has eluded me is the piece I need to go from that elbow inside my cabin up through the roof. I would love to get this completed before the snow flies (October 31), and I've finally got time to begin my research. And I'm damn sure going to install one of those vee shaped snow guards on my roof. Thanks!

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It looks to me like you need a whole new chimney quite honestly.
 
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coaly

Fisher Moderator
Staff member
Dec 22, 2007
4,235
NE PA
The parts you need are brand specific to your support box.

Inside the support box is a ring identical to the top of a chimney pipe section. This is called a starter section. Companies change the design at times, so it is possible to have an older support box not compatible with a newer style pipe. As an example, I had a 25 year plus old chimney from Dura-vent that I needed to change chimney pipe sections. They changed the piece in the bottom of the new support box that now has air intakes in the base ring attached to the bottom of the box. I had to get a new support box and screw the new style starter ring to the box to match the new style pipe. Technically to be installed as tested, the entire support box should have been changed.

You can’t mix one brand chimney system with another. They are a tested, “Listed” unit.

There are two types of chimney pipes. Double wall, and triple wall. The double wall, or “pack chimney” has heavy dense insulation between the stainless inner flue and outer pipe wall. This type measures 1 inch thick, so a 6 inch inner flue measures 8 inches outside. They stay hotter inside easier, and are superior to the triple wall type. Double wall is also a bit more expensive.

The 3 wall type chimney pipe has a thin insulation wrap around the inner flue pipe. A center pipe with 1 inch airspace to the outer third wall pipe. This type measures 2 inches thick walls, so the outside dimension of a 6 inch flue will be 10 inch diameter outside.

The pipe from stove to support box is called connector pipe. Yours is single wall. The adapter piece missing is a short single wall part that snaps into the support box. Again, this part is brand specific for the chimney support box.

It is cheaper to buy a Chimney kit for through the roof install and have all the parts needed. If the support box is damaged, you will need to change it. I have cut the bottom out of my own old box without removing from ceiling and screwed the bottom of a new box into the original using the existing box as a mount piece for the new starter section. Since all parts of the system need to be installed as tested to UL testing criteria, you can’t legally modify any parts since it needs to be installed “as tested”.
 

coaly

Fisher Moderator
Staff member
Dec 22, 2007
4,235
NE PA
I guess we answered your question at the same time. The short and long answer, both correct.
 
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Blazzinghot

Member
Dec 5, 2019
130
New Plymouth, Idaho
coaly I am trying to follow what you are saying. My set up is similar to this one in the picture where the connection meets the ceiling support box and the way I solved it was making a two sided crimped pipe. I have the crimping tool as it comes in handy but I don't like the idea of creosote coming down the outside of the pipe. Don't they make an end piece on the double or triple insulated pipe with a crimped end so the single wall pipe inside the home slides over the top like is is supposed to?

I was just doing some checking and this appears to be a helpful answer to my own question.
Am I off base or is this a solution to this person's question?
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
25,020
central pa
coaly I am trying to follow what you are saying. My set up is similar to this one in the picture where the connection meets the ceiling support box and the way I solved it was making a two sided crimped pipe. I have the crimping tool as it comes in handy but I don't like the idea of creosote coming down the outside of the pipe. Don't they make an end piece on the double or triple insulated pipe with a crimped end so the single wall pipe inside the home slides over the top like is is supposed to?

I was just doing some checking and this appears to be a helpful answer to my own question.
Am I off base or is this a solution to this person's question?
Yes there should be an adapter of some sort sticking down that the connector pipe slides over. Different manufacturers do it in different ways but they all supply some sort of stove pipe adapter
 

tightxstack

Member
Nov 10, 2016
3
Earth
Thanks for these replies, this has cleared up some questions and narrowed down what I need to look for. I particularly like the idea of running a new support box up through my existing box if need be.
 

coaly

Fisher Moderator
Staff member
Dec 22, 2007
4,235
NE PA
Thanks for these replies, this has cleared up some questions and narrowed down what I need to look for. I particularly like the idea of running a new support box up through my existing box if need be.
I had to cut the corners of a square box to get the new one inside it about 4 inches. Then screwed into joists through the old box. May have to slice the old round one to get the new one inside it a couple inches. Much easier than removing the support box and opening the roof!
 

coaly

Fisher Moderator
Staff member
Dec 22, 2007
4,235
NE PA
coaly I am trying to follow what you are saying. My set up is similar to this one in the picture where the connection meets the ceiling support box and the way I solved it was making a two sided crimped pipe. I have the crimping tool as it comes in handy but I don't like the idea of creosote coming down the outside of the pipe. Don't they make an end piece on the double or triple insulated pipe with a crimped end so the single wall pipe inside the home slides over the top like is is supposed to?

I was just doing some checking and this appears to be a helpful answer to my own question.
Am I off base or is this a solution to this person's question?
The style I run into has a very thin opening between the outside of inner flue pipe and box for the adapter to fit OVER the flue pipe and tightly fit inside the bottom of box opening. No room for a crimp, it is a tight slot. The adapter usually has little bent tabs that latch onto the box making it extremely difficult to take out. When you snap them into the box they are really in there.