Stove in attic - vent with 90 into brick chimney, OR use Class A pipe straight through metal roof?

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New Member
Jan 10, 2022
94
Northeastern Vermont
I have a big antique cast iron wood stove in my attic (which is my sot of men's club with my drums, etc.). It is a completely unheated room. It gets only occasional use and I want to be able to fire up the stove just for times when hanging out there.

The stove is up against a masonry chimney and has stovepipe that goes up, and through a 90 degree elbow into the chimney (typical). The chimney is completely unlined old brick. The obvious answer is a stainless steel liner.

However, is it any better or any worse to just go from the stove straight up through the ceiling (just a few feet above the stove) into some tripe wall insulated class A chimney pipe?

I don't think the difference in material costs is going to be significant. I like the idea of going straight out (especially on a short chimney). The only thing worrying me is cutting through an old metal roof, as people around town (who like to talk but know nothing) say that cutting a hole is nothing but problems and it will always leak. I did a ton of work in the Yukon for many years, and nearly everybody had such triple wall chimney pipe and they worked well and I never heard of leaking being prevalent.

The advantage of using the masonry chimney is mostly cosmetic (both inside and outside). It is also very easy and I can have the thing connected right away, rather than waiting until summer to play around cutting holes. I do need to use the chimney for other things one existing liner and probably need to add a second, but it is so huge that I may be able to fit this third liner in there.

IMG_0178.JPG
 

rijim

Feeling the Heat
Jan 19, 2009
262
RI
Is it working well as is? If you plan on upgrading to a newer, secondary burn or CAT stove you will likely need a 16’ or greater chimney height above the fire box. You may want to consider that before making any changes.
 

kennyp2339

Minister of Fire
Feb 16, 2014
6,604
07462
If adding individual liners then its fine to use the chimney, since its acting as a chase, big no no if you running multiple appliances into one large hole though, also remember draft is the engine that runs the stove, so having a short run will affect stove function
 
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stoveliker

Minister of Fire
Nov 17, 2019
5,242
Long Island NY
straight up (minimizing elbows and horizontal sections) always drafts better. And given that you are likely having a short flue, i'd go straight up - if aesthetics allow that in this old home.
 

N.E.K. - D.D.S.

New Member
Jan 10, 2022
94
Northeastern Vermont
Is it working well as is? If you plan on upgrading to a newer, secondary burn or CAT stove you will likely need a 16’ or greater chimney height above the fire box. You may want to consider that before making any changes.
To be honest, I have not tried it. There is no steel liner and the chimney is completely unlined old masonry. It would be interesting to try a small supervised fire. It is -15 F (-27 C) here now. Maybe I will try it in the next days. I would like to seal up the pipe with refractory cement (the pipe is just sort of sitting in there at the moment)... but of course I am considering a steel liner so have not sealed it.

I will not be putting a modern stove in this area. The newer (approx 1850-1855) part of the house is made of brick. On that side I have a small Jotul 3TDIC-2 and am also installing a Woodstock Fireview (shown on previous post trying to decide on insulated rigid liner), both of which have catalysts.

The older part of the house (early 1800's?) is made of wood. It contains just the kitchen, dining room, and attic/men's club (which you see in the photo). I have 3 old unsealed antique wood stoves on this side (one in each room), and they are actually quite good because they will only be used as needed and provide rapid comfortable heat. The rooms can cool down the rest of the time. The kitchen has a small "morning stove" for example, which heats the area in moments when I wake up, make coffee, etc. It is so perfect for its application that I would not change it for the world.

The one in the attic is a bit special because it was made very locally in the town just 3 miles away, and I never knew stoves were made there. Most of the time it just sits there, and the room is unheated, but I want to use it when playing drums, or darts, or hanging out in that room.
If adding individual liners then its fine to use the chimney, since its acting as a chase, big no no if you running multiple appliances into one large hole though, also remember draft is the engine that runs the stove, so having a short run will affect stove function
This old house of course had all sorts of things just dumping into the large masonry chimney. This stove goes into the completely unlined brick chimney and I therefore have not used it. Am I correct to assume that it will draft better on a 6" liner?

The thing I am trying to decide is a flex liner in the chimney or go straight up through the roof and into class A pipe... probably triple wall due to cold winters here and short run. Deprnding on stove position, I have 5 or 5.5 feet from the top of stove to the ceiling and roof. The masonry chimney is what? 5 and half more feet? A class A chimney would probably be similar. So it may just be 11 foot long chimney. Although this old stove will probably be quite forgiving and work fine with that. Remember, I will be making some hot clean fires, heating up that large heavy iron stove, and letting it burn out. I won't be doing any slow overnight burns or anything.
straight up (minimizing elbows and horizontal sections) always drafts better. And given that you are likely having a short flue, i'd go straight up - if aesthetics allow that in this old home.
I do agree that straight is going to be the absolute best performance, and it allows me to do a really well insulated chimney pipe. Doing black stove pipe up to the ceiling is not too much difference from having the elbow into the chimney. It is a bit weird to have a stainless steel chimney on the roof right next to the brick chimney. But it may be fine. I would do it if it really will improve performance.... I am just wondering about cutting the hole in the metal roof and then getting it to not leak (it is old standing seam roof).

People say to change the roof, but that is crazy. I LOVE this roof. It is ugly rusted at the moment, but it is just surface rust. It only needs a bit of brushing and painting. The new metal roof on the newer brick section of the house leaks (done by previous owners). This OLD roof does not leak.

The guys in the USA that like to install flex liner will probably say that is the way to go. The guys in the Yukon would say I am an idiot to do anything other than triple wall class A pipe. Hmmm.
 

N.E.K. - D.D.S.

New Member
Jan 10, 2022
94
Northeastern Vermont
To be honest, I have not tried it. There is no steel liner and the chimney is completely unlined old masonry. It would be interesting to try a small supervised fire. It is -15 F (-27 C) here now. Maybe I will try it in the next days. I would like to seal up the pipe with refractory cement (the pipe is just sort of sitting in there at the moment)... but of course I am considering a steel liner so have not sealed it.

I will not be putting a modern stove in this area. The newer (approx 1850-1855) part of the house is made of brick. On that side I have a small Jotul 3TDIC-2 and am also installing a Woodstock Fireview (shown on previous post trying to decide on insulated rigid liner), both of which have catalysts.

The older part of the house (early 1800's?) is made of wood. It contains just the kitchen, dining room, and attic/men's club (which you see in the photo). I have 3 old unsealed antique wood stoves on this side (one in each room), and they are actually quite good because they will only be used as needed and provide rapid comfortable heat. The rooms can cool down the rest of the time. The kitchen has a small "morning stove" for example, which heats the area in moments when I wake up, make coffee, etc. It is so perfect for its application that I would not change it for the world.

The one in the attic is a bit special because it was made very locally in the town just 3 miles away, and I never knew stoves were made there. Most of the time it just sits there, and the room is unheated, but I want to use it when playing drums, or darts, or hanging out in that room.

This old house of course had all sorts of things just dumping into the large masonry chimney. This stove goes into the completely unlined brick chimney and I therefore have not used it. Am I correct to assume that it will draft better on a 6" liner?

The thing I am trying to decide is a flex liner in the chimney or go straight up through the roof and into class A pipe... probably triple wall due to cold winters here and short run. Deprnding on stove position, I have 5 or 5.5 feet from the top of stove to the ceiling and roof. The masonry chimney is what? 5 and half more feet? A class A chimney would probably be similar. So it may just be 11 foot long chimney. Although this old stove will probably be quite forgiving and work fine with that. Remember, I will be making some hot clean fires, heating up that large heavy iron stove, and letting it burn out. I won't be doing any slow overnight burns or anything.

I do agree that straight is going to be the absolute best performance, and it allows me to do a really well insulated chimney pipe. Doing black stove pipe up to the ceiling is not too much difference from having the elbow into the chimney. It is a bit weird to have a stainless steel chimney on the roof right next to the brick chimney. But it may be fine. I would do it if it really will improve performance.... I am just wondering about cutting the hole in the metal roof and then getting it to not leak (it is old standing seam roof).

People say to change the roof, but that is crazy. I LOVE this roof. It is ugly rusted at the moment, but it is just surface rust. It only needs a bit of brushing and painting. The new metal roof on the newer brick section of the house leaks (done by previous owners). This OLD roof does not leak.

The guys in the USA that like to install flex liner will probably say that is the way to go. The guys in the Yukon would say I am an idiot to do anything other than triple wall class A pipe. Hmmm.
Oops, I meant heavily insulated Class A chimney pipe. It seems I was a bit confused on double vs triple wall (this forum says double is better). I thought I remembered pipe with two layers of insulation that we used in the arctic. But I could be mistaken.
 

stoveliker

Minister of Fire
Nov 17, 2019
5,242
Long Island NY
With the right parts is should be possible to go thru the roof without leaks. Remember there are many pipes going thru roofs all over the place and only a small fraction leaks - probably due to installation errors.