Plumbing free standing wood stove into a 6”x8” clay chimney flue

[cmyers]

Hello all.

I recently acquired a Drolet Columbia II 1800sqft stove. I was told I should have an insulated liner to operate the stove. However, I don’t have enough clearance to install a 6” liner with insulation. The clay flue measures exactly 6”x8”x20’. Would I be alright just by plumbing the stove into the existing flue? The flue is in excellent condition besides a couple frayed edges up top.

 

[begreen]

It depends on the chimney clearance from combustibles. To use without insulation the chimney needs 1" clearance if exterior and 2" if interior. This is for the entire length.

 

[bholler]

Hello all.

I recently acquired a Drolet Columbia II 1800sqft stove. I was told I should have an insulated liner to operate the stove. However, I don’t have enough clearance to install a 6” liner with insulation. The clay flue measures exactly 6”x8”x20’. Would I be alright just by plumbing the stove into the existing flue? The flue is in excellent condition besides a couple frayed edges up top.

You definitely want a properly sized liner and it probably needs to be insulated to meet code requirements. Your options are an oval liner or remove the clay liners

 

[cmyers]

Thank you, guys. I had a local chimney sweep find me a liner that will fit my chimney and allow 1/4" of insulation to be wrapped around the liner. I realize it should be 1/2". For now, it's the best I can do to get my stove going for the winter.

 

[bholler]

Thank you, guys. I had a local chimney sweep find me a liner that will fit my chimney and allow 1/4" of insulation to be wrapped around the liner. I realize it should be 1/2". For now, it's the best I can do to get my stove going for the winter.

No you can get an oval liner and 1/2" will fit or remove the clay and 1/2" will fit

 

[cmyers]

No you can get an oval liner and 1/2" will fit or remove the clay and 1/2" will fit

The only oval liner I could find that would fit would be 4"x8" and allow for proper draft. That still leaves me in a pickle on the insulation fitting part as the clay liner is 6"x8". At the moment I'm not prepared to do a clay removal due to time constraints with other projects for clients. However, next spring I'd be very willing to remove the clay.

 

[cmyers]

No you can get an oval liner and 1/2" will fit or remove the clay and 1/2" will fit

Do you condone squishing a liner a little bit to fit insulation? My apologies for my ignorance. I'm a builder by trade. I know code for most other things, but chimneys are not my thing.

 

[bholler]

The only oval liner I could find that would fit would be 4"x8" and allow for proper draft. That still leaves me in a pickle on the insulation fitting part as the clay liner is 6"x8". At the moment I'm not prepared to do a clay removal due to time constraints with other projects for clients. However, next spring I'd be very willing to remove the clay.

6x8? That's an odd one. Yeah that would be hard to get anything in.

 

[cmyers]

6x8? That's an odd one. Yeah that would be hard to get anything in.

It depends on the chimney clearance from combustibles. To use without insulation the chimney needs 1" clearance if exterior and 2" if interior. This is for the entire length.

Update on my situation. My chimney has 3 sections in it. One for my boiler, one for fireplace, and one for a wood stove in the basement. I’m going to set aside some time in the next couple weeks to remove the clay flue for the basement wood stove section. Plan to put a stove in the basement rather than the fireplace.

Do you think I’ll have a draft issue? The length of the chimney would be around 27’ from top to thimble in the basement.

 

[stoveliker]

Does it have a horizontal section before entering the flue?
If so how many feet?

Basements can have negative pressures relative to the rest of the house. But a 27' flue could work. That's what I have.
But my basement in particular is not very tightly air sealed.

 

[cmyers]

Does it have a horizontal section before entering the flue?
If so how many feet?

Basements can have negative pressures relative to the rest of the house. But a 27' flue could work. That's what I have.
But my basement in particular is not very tightly air sealed.

Yes. The horizontal section is roughly 10” long before it enters the flue. My basement has a leaky bulkhead door and then a barn door that is also leaky as you go down the steps from the bulkhead. Not too bad, but you notice it on a windy day.

 

[stoveliker]

10" is very short (does the stove have a rear exit?)

It would work best if your upper floors are properly air sealed to avoid a competing chimney effect in the home.

 

[cmyers]

10" is very short (does the stove have a rear exit?)

It would work best if your upper floors are properly air sealed to avoid a competing chimney effect in the home.

Just measured the horizontal section. It is 12” exactly. Stove has a top exit. Thimble is roughly 7 feet up from the basement floor. Floors are 3/4 CDX for subfloor and hardwood shiplap for finished floor. It is sealed quiet well.

 

[stoveliker]

Okay. What I meant is if the windows upstairs and the attic etc. are air sealed well.

Would you be able to post a pic that includes the horizontal section?
I don't understand how it can be that short. (Tho I don't think it matters as 27 ft will likely be enough anyway.)

Begreen may be a bit more hesitant but I'd say to go ahead.

 

[cmyers]

Okay. What I meant is if the windows upstairs and the attic etc. are air sealed well.

Would you be able to post a pic that includes the horizontal section?
I don't understand how it can be that short. (Tho I don't think it matters as 27 ft will likely be enough anyway.)

Begreen may be a bit more hesitant but I'd say to go ahead.

Oh I see what you mean. That went right over my head. Main floor has a couple leaky older windows, but mostly airtight. I have a cathedral ceiling with half a loft. It is a log cabin. Here’s a photo of the horizontal into the flue.

 

[stoveliker]

Okay.
Drafty windows suck.
Also.was the basement insulated? If not you will loose a lot (1/3) of the heat already there.

That may be 12" but your stove won't be against the wall, and the 90 deg inside and outside will add space too. That'll easily be 2.5 ft.in total.

I wonder now because of the leakage upstairs...

I'll let others give their opinion.

 

[cmyers]

Okay.
Drafty windows suck.
Also.was the basement insulated? If not you will loose a lot (1/3) of the heat already there.

That may be 12" but your stove won't be against the wall, and the 90 deg inside and outside will add space too. That'll easily be 2.5 ft.in total.

I wonder now because of the leakage upstairs...

I'll let others give their opinion.

The basement is insulated besides the bulkhead door which I plan to insulate before winter hits. Basement walls have 2” blue board foam glued to them.

I see what you mean now by horizontal length. I’m a bit ignorant in this department, but capable lol.

The leakage isn’t too bad, but enough to feel a small draft on the really windy days. Thank you for your time.

 

[Todd]

If the clay liner is in excellent shape why not try it that way first? Was it inspected and up to code? It won’t draft as well as an insulated liner but it may be good enough til you have time to upgrade.

 

[stoveliker]

Because safety and code?
At the very least that should be checked.

 

[Todd]

That’s why I asked if it was up to code.

 

[stoveliker]

My bad, missed that.

 

[cmyers]

If the clay liner is in excellent shape why not try it that way first? Was it inspected and up to code? It won’t draft as well as an insulated liner but it may be good enough til you have time to upgrade.

It’s not up to code. Chimney was relined with the current flue in the 70s. I put a scope down and found multiple cracks and separations of flue seams. Also doesn’t meet UL-1777 standard.

 

[cmyers]

I put an order in for a tile breaker through Rockford Chimney this morning. Should be here sometime next week. Will put out an update with pictures when it’s all done. Thank you all for the valuable information.

 

[stoveliker]

Congrats on doing it right (and sleeping better with a better-performing set up).

 

[cmyers]

If the clay liner is in excellent shape why not try it that way first? Was it inspected and up to code? It won’t draft as well as an insulated liner but it may be good enough til you have time to upgrade.

The fireplace flue is in excellent shape. My original plan was to put a free standing stove in front of the fireplace. I’m switching directions and putting a stove in the basement now. That flue is ruined.