Chimney replacement options

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spirilis

Minister of Fire
Sep 8, 2009
940
Baltimore, MD
I want to weigh my options for replacing my current chimney so I'd like to gather some ideas from you guys. Here's my current layout:

19ft tall outside masonry chimney with terra cotta clay tile, 12x12 (actual ID is 10.785x11.385 or so at the top tile, but close enough) goes from the basement to the roof. Unfortunately, the builders put two woodstoves into this big flue, violating modern code for sure (dunno if that was code back in 1981 when the house was built?). Upstairs has a 8" thimble going into the flue and the downstairs has a 6" thimble going into the flue. The upstairs stove's thimble-to-exit height is around 9ft, and the downstairs is around 15ft or so (probably 19ft effective flue height if you count the stove & pipe, as the firebox bottom is about level with the cleanout). As far as I could see while lowering a lamp down the chimney and peeking at it, it's a straight shot all the way to the bottom, no bends.
BTW, the house itself is around 1600sqft total including the basement level. I don't care too much about heating the basement though. Current setup includes a 1980 VC Defiant (II) upstairs (8" flue) and a 1984 Jotul 8 (first generation, no cat, has a rotary air control dial at the bottom of the door) downstairs (6" flue).

I'd love to keep both hearths functional, for future resale value (although the downstairs one could be ripped out if need be, I guess). What options might I have?

I noticed the upstairs stove heats the livable space much better, but the previous owners claimed the downstairs stove "can heat the whole house!" ... can't say I've seen evidence of that as a nice hot fire in that Jotul hardly heats the upstairs more than 1 degree at the thermostat with the basement door open. The VC Defiant upstairs, otoh, will roast the house, and even warm the basement a bit with the HVAC fan running (return duct is in the hallway near the thermostat, on a wall up near the ceiling, so a well placed box fan moves the heat over there quite well).

Anyway the point of this thread is to inquire about chimney options--

Option 1: 8" liner to the top thimble, nothing else, axe the basement hearth and close it off.
Pros: Should improve draft for the Defiant. (The Defiant does have some draft problems, not outright backpuffing but I often have to stoke the fire with the side door open to stop it from smoldering)
Cons: Doesn't solve the flue height problem (still a 9ft high flue, or 10ft I guess when counting the firebox), also axes the basement hearth. Guess I could have the brick removed and carpeted over though. The exterior-side wall down there is a huge solid slab of plaster, I think, no brick going up the wall just brick on the floor. The basement is finished, with some wood panel walls all around and a small garage.

Option 2: 6" liner to the bottom thimble, nothing else, axe the upstairs hearth and close it off
Pros: Will provide excellent draft with a 19ft tall flue, and I can replace that Jotul with any EPA stove right away if I wanted.
Cons: Far as I can tell a downstairs stove doesn't heat the house very well, as there are no nearby HVAC return vents and the air doesn't go upstairs much (if anything, it pools at the top of the basement stairwell and goes into the attic). Also deactivates the upstairs hearth, which is a bigger deal (brick on the floor and up the wall, hardwood flooring original from 1981 up there, it'd just be ugly not having a stove there...)

Option 3: 6" liner to the top thimble, nothing else, axe the Defiant and put the Jotul or an EPA stove up there, close off the downstairs thimble.
Pros: Makes the upstairs thimble ideal for most modern EPA stoves with 6" pipes
Cons: Doesn't solve the flue height problem (still a 9ft flue), and deactivates the basement hearth.

Is it possible to install a liner, then extend it further up using triple-wall pipe? That'd remove one of the cons from options #1 and #3. Only concern I may have is I'd probably have to get a permit from my HOA as it changes the look of the house a bit (a huge pipe coming out of a masonry chimney, just looks funny), but I doubt that'll be much of an issue.

Any liners I put in I'd like to be insulated, as it's still an external masonry structure.

What are some other options? I think the chimney sweep folks I talked to back in Sept. said it may be possible to put two ovalized 6" liners in there if they smashed out all the terra cotta, but said that's a pain and required breaking through some of the wall(?) not sure if that's what he said but he made it sound like a pain.
What about a 6" liner to the upstairs thimble and something like a 3-4" liner downstairs, where I (or a future owner) could put in a pellet stove? That'd regain use of both hearths, allow one to heat the whole house very well from upstairs and provide some nice heat downstairs if need be.

Anyway all your suggestions are appreciated, and I thank you all for making this site very informative!
 
I realize you've asked a bunch of questions, & I'll let other chime in for them...

<>Is it possible to install a liner, then extend it further up using triple-wall pipe? That’d remove one of the cons from options #1 and #3. Only concern I may have is I’d probably have to get a permit from my HOA as it changes the look of the house a bit (a huge pipe coming out of a masonry chimney, just looks funny), but I doubt that’ll be much of an issue.<>

Yes you can do this. There is an anchor plate available from MOST (if not all) Class A chimney manufacturers...
Just make sure you buy your Class A from one of them.
Yes it may look funny.
You will hafta add a roof brace kit for additional strength/security...
HTH
 
DAKSY said:
I realize you've asked a bunch of questions, & I'll let other chime in for them...

<>Is it possible to install a liner, then extend it further up using triple-wall pipe? That’d remove one of the cons from options #1 and #3. Only concern I may have is I’d probably have to get a permit from my HOA as it changes the look of the house a bit (a huge pipe coming out of a masonry chimney, just looks funny), but I doubt that’ll be much of an issue.<>

Yes you can do this. There is an anchor plate available from MOST (if not all) Class A chimney manufacturers...
Just make sure you buy your Class A from one of them.
Yes it may look funny.
You will hafta add a roof brace kit for additional strength/security...
HTH
That does help. Thanks!
 
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