Venting into masonry chimney

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

StihlKicking

Feeling the Heat
Jan 12, 2016
488
Hatchie Bottom, MS
I have a solid masonry interior fireplace in my living room. It’s 35ft tall with a 12x12” teracota liner. It’s 5 years old and has had less than 6 fires a year built in it. I was thinking of putting a small wood stove in the fireplace something along the lines of a 2b or a 602. This stove would be used less than 6 times a year for ambiance only. The problem with the open fireplace is the hurricane force draft it creates in the whole house when lit.

I was thinking of putting 10 ft of 4x8 rectangle flex pipe through the damper and into the liner with a lower block off plate and adapter for 6” stove pipe.

My question is will this setup have enough draft to prevent smoke spillage or back puffing? Also I don’t won’t to be unsafe but assuming this would produce sufficient draft would creosote be a problem with burns this limited and thorough cleanings?

I understand that a full liner from top to bottom is the best but I’m not prepared to do that at this time considering the limited use of this fireplace.

Bottom line is will it produce enough draft?

Thanks in advance for your opinions and advice.
 
NO,that will not provide you the "Draft" you are looking for.
You really need to run the Chimney Liner the full length of the chimney - 35 ft
For that kind of distance a 6" Round will be easier to install, and would be less expensive, if your stove has a 6" outlet.
Probably to meet code and for better performance the liner should be insulated.
If you only went with a partial liner it would very difficult to clean both the stainless liner and the clay flue tiles.
 
  • Like
Reactions: Woody Stover
I have both a 3 cu ft wood stove and a 2 Cu ft wood stove both vented into that exact same size flue on 2 different floors. A 12x12 terra cotta lined masonry chimney. Surprisingly Both stoves work very well with it. Either when used individually or both at once. Cant say for sure if that applies in all cases.
 
I have both a 3 cu ft wood stove and a 2 Cu ft wood stove both vented into that exact same size flue on 2 different floors. A 12x12 terra cotta lined masonry chimney. Surprisingly Both stoves work very well with it. Either when used individually or both at once. Cant say for sure if that applies in all cases.
But this will be stubbed up through a fireplace. No one here can say how it will draft, it likely won’t do well I’ll bet.

This type of installation is impossible to clean without a total tear down including removing the block off plate. It’s not safe, or acceptable. Just wait till you can install the stove properly and safely.
 
Are you burning with the damper wide open? I think the extra hassle of cleaning the partial liner and flue vs just the clay tiles would mean I would be less likely to go that route.

Do you have fireplace doors? Mine had controllable vents at the bottom. That could be another option. I waited 9 years to put a stove in. Burned wood in the fireplace only 3 times the first year. After I paid 500$ to have it cleaned and to be told it needed substantial work. That was enough for level 2 creosote, another 200$ cleaning. I went to ethanol burners for 5 years. Burned with damper closed. Worked well and was cheap enough. Three 5k btu burners. 300$ for burners and 65$ a year for fuel. They weren’t the greatest abidance but fit my budget at the time. I could just barely smell them burning if I came in from outside with the damper closed. I’m glad to have my stove now.

My thoughts are to do right the first time. Insulated liner and an up to code install. 35’ is a lot of cold clay that will the the creosote will condense on and run down past the partial liner where it will never get hot enough to burn off until maybe one day it does. I won’t buy another home without a chimney inspection after what I found in my current house and seeing some picture here on the forum. I hope my thoughts are helpful.

Evan.
 
I have both a 3 cu ft wood stove and a 2 Cu ft wood stove both vented into that exact same size flue on 2 different floors. A 12x12 terra cotta lined masonry chimney. Surprisingly Both stoves work very well with it. Either when used individually or both at once. Cant say for sure if that applies in all cases.

What brand of stoves are you using? And how do you deal with cleaning? Complete tear down of the chimney system?
 
What brand of stoves are you using? And how do you deal with cleaning? Complete tear down of the chimney system?
I think he has a traditional masonry flue, not a fireplace like you.
 
What brand of stoves are you using? And how do you deal with cleaning? Complete tear down of the chimney system?
If i had problems i wouldnt be using it. One Country Hearth 2000 and One Englander 30-NC.It is not a fireplace. Regular (very large)Flue lined Masonry Chimney. No draft issues.
 
  • Like
Reactions: StihlKicking
Thanks for the reply’s. I may just hold off since it’s not imperative to have a stove for primary heat. Not to ask ignorant questions, I just don’t have a good knowledge base of modern stoves and exactly how they operate. My knowledge only extends to old school stoves we had when I was a kid.
 
Any opinions on ovalizing a round liner just to get trough the flue if I went with a top down liner?
 
Why do you need to ovalized? A 6 inch liner even insulated should fit. If its just tight at the damper area just cut the damper out.
 
The problem with the open fireplace is the hurricane force draft it creates in the whole house when lit.


Unfortunately, you have discovered a major reason why conventional fireplaces have been rendered obsolete for all but the most determined fireplace users.

I will throw out the possibility that you might find a direct vent gas stove insert satisfactory for your fireplace.

For one thing, you are very likely going to use it far more often, and gas fireplace inserts can have flames that are quite attractive these days.And they burn gas pretty efficiently and provide radiant heating much like a fireplace, but far simpler to use these days. I was looking over one fireplace that has a remote control that turns on the fireplace to maintain room temperature with a remote thermostat, and raises and lowers the flame height to help maintain the temperature, rather than just turning the fireplace on and off.

A direct vent insert could be vented out the back of your existing fireplace with a fitting on the exterior of the house behind the fireplace that captures fresh air from outdoors to burn the gas, and then vets the combustion gasses outdoors through the same fitting.

This would also eliminate drafts up the chimney altogether.

Those on this board tend to dote on burning wood, but far more people are choosing gas fireplaces than wood fireplaces or stoves these days.
 
I have both a 3 cu ft wood stove and a 2 Cu ft wood stove both vented into that exact same size flue on 2 different floors. A 12x12 terra cotta lined masonry chimney. Surprisingly Both stoves work very well with it. Either when used individually or both at once. Cant say for sure if that applies in all cases.
It doesn't apply in most cases. And I would bet you would be amazed with the difference if they were hooked up correctly
 
I have a solid masonry interior fireplace in my living room. It’s 35ft tall with a 12x12” teracota liner. It’s 5 years old and has had less than 6 fires a year built in it. I was thinking of putting a small wood stove in the fireplace something along the lines of a 2b or a 602. This stove would be used less than 6 times a year for ambiance only. The problem with the open fireplace is the hurricane force draft it creates in the whole house when lit.

I was thinking of putting 10 ft of 4x8 rectangle flex pipe through the damper and into the liner with a lower block off plate and adapter for 6” stove pipe.

My question is will this setup have enough draft to prevent smoke spillage or back puffing? Also I don’t won’t to be unsafe but assuming this would produce sufficient draft would creosote be a problem with burns this limited and thorough cleanings?

I understand that a full liner from top to bottom is the best but I’m not prepared to do that at this time considering the limited use of this fireplace.

Bottom line is will it produce enough draft?

Thanks in advance for your opinions and advice.
Don't do it. Even if it works ok which is unlikely it will be a real pita to service
 
I know many here will predict gloom and doom with the chimney you have. If it was me, I'd try it and see. A friend had a new stove and masonry outside chimney. I don't know who's idea the chimney was. But I did work well. The many times I was there the draft looked to good. It looked like it was sucking down wood.
 
  • Like
Reactions: StihlKicking
I know many here will predict gloom and doom with the chimney you have. If it was me, I'd try it and see. A friend had a new stove and masonry outside chimney. I don't know who's idea the chimney was. But I did work well. The many times I was there the draft looked to good. It looked like it was sucking down wood.
Masonry chimneys are just fine if done right. Venting through a fireplace into a drastically oversized clay liner with no real connection to the clay is not ok. I see setups like this all the time and very few of them work in a way I think is useable.
 
  • Like
Reactions: webby3650
Masonry chimneys are just fine if done right. Venting through a fireplace into a drastically oversized clay liner with no real connection to the clay is not ok. I see setups like this all the time and very few of them work in a way I think is useable.
I agree. There’s no way we’d clean a setup like that. It would be an estimate to correct the problem instead.
 
I agree. There’s no way we’d clean a setup like that. It would be an estimate to correct the problem instead.
Same here. We do clean a few direct connects but they were done by a guy who actually mortars the stainless into the clay. I don't know how he does it and he won't tell anyone.
 
Lots of room in a 12 x 12 liner to drop in a double walled stainless 6" flue system.
 
  • Like
Reactions: 2fireplacesinSC
I have a solid masonry interior fireplace in my living room. It’s 35ft tall with a 12x12” teracota liner. It’s 5 years old and has had less than 6 fires a year built in it. I was thinking of putting a small wood stove in the fireplace something along the lines of a 2b or a 602. This stove would be used less than 6 times a year for ambiance only. The problem with the open fireplace is the hurricane force draft it creates in the whole house when lit.

I was thinking of putting 10 ft of 4x8 rectangle flex pipe through the damper and into the liner with a lower block off plate and adapter for 6” stove pipe.

My question is will this setup have enough draft to prevent smoke spillage or back puffing? Also I don’t won’t to be unsafe but assuming this would produce sufficient draft would creosote be a problem with burns this limited and thorough cleanings?

I understand that a full liner from top to bottom is the best but I’m not prepared to do that at this time considering the limited use of this fireplace.

Bottom line is will it produce enough draft?

Thanks in advance for your opinions and advice.
Don't waffle and don't half-ass it. Just do it right, then use it more often so that you can justify it to yourself. And it'll be great.

You don't seem like the kind of guy who would consider what you are considering.
 
  • Like
Reactions: bholler
Don't waffle and don't half-ass it. Just do it right, then use it more often so that you can justify it to yourself. And it'll be great.

You don't seem like the kind of guy who would consider what you are considering.

I definitely don’t plan on half-assing anything! After reading the many responses from the experts here I will either be relining the chimney or just leaving it an open fireplace that rarely gets used. The jury is still out on that.
 
I definitely don’t plan on half-assing anything! After reading the many responses from the experts here I will either be relining the chimney or just leaving it an open fireplace that rarely gets used. The jury is still out on that.
Great.

I am curious why you only use it occasionally, and if it becomes an effective heater, why you wouldn't it be used more frequently?

This was the liner kit I used. Thin wall, but decent. If you decided to insulate, add another $250.
https://myfireplaceproducts.com/us_...nless-flex-liner-kit-for-wood-stove-volka-635
 
Great.

I am curious why you only use it occasionally, and if it becomes an effective heater, why you wouldn't it be used more frequently?

This was the liner kit I used. Thin wall, but decent. If you decided to insulate, add another $250.
https://myfireplaceproducts.com/us_...nless-flex-liner-kit-for-wood-stove-volka-635

Thanks ED that is a good price for a 35’ liner. I am spoiled to my OWB that heats through my central system. That’s the main reason I don’t plan on running a stove very often.
 
Thanks ED that is a good price for a 35’ liner. I am spoiled to my OWB that heats through my central system. That’s the main reason I don’t plan on running a stove very often.
Oh, I either forget you were heating with a boiler, or never knew. Now it all makes sense!

I bet you'd really enjoy having the stove inside, not just for that extra shot of radiant stove heat, but it's just wonderful having the fire inside. And I bet you'd use it a bunch, once you had it working. But, with a boiler, it's totally a luxury, rather than a necessity. And a significant cost.

I think you deserve that luxury, but obviously it's your call.
 
  • Like
Reactions: StihlKicking