Wood stove question, Will venting sweat

[heiert]

This is my first time posting. We have been looking into adding a small wood stove like the Vermont Casting Aspen. The business I was talking to sent me a message regarding the install.

“The installers concern is that there won’t be a lot of attic space, so the venting will sweat. It is not a question as to if it will sweat, but when and how much. It would be an environmental issue and may damage the wood ceiling.”

My house is an older 2 story house built in 1883 with a 18x18 room addition, just ceiling with no attic, where I would want to have the wood stove. The install would go through the roof of the room addition and the chimney would extend up attached to the 2 story brick house for proper drafting.

I see other buildings/cabins that don’t have attics with a wood stove installed. Is the venting sweating a problem and what are others doing to prevent it?

Thank you for any insight that you may have.

 

[begreen]

The chimney pipe is well insulated. I would be less concerned about sweating than about poor drafting. Chimneys in 1 story additions have a track record of poor draft. Extra height may compensate.

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[heiert]

The chimney would extend above the peak of the 2nd story. There shouldn’t be a drafting problem.
Thank you for your reply.

 

[begreen]

That definitely will help. Based on the description it sounds like the chimney will be supported in a cathedral ceiling support box. If so, that can also be insulated. Even better for keeping the chimney pipe warm would be if the chimney pipe was enclosed in a chase.

 

[jjam]

This is my first time posting. We have been looking into adding a small wood stove like the Vermont Casting Aspen. The business I was talking to sent me a message regarding the install.

“The installers concern is that there won’t be a lot of attic space, so the venting will sweat. It is not a question as to if it will sweat, but when and how much. It would be an environmental issue and may damage the wood ceiling.”

My house is an older 2 story house built in 1883 with a 18x18 room addition, just ceiling with no attic, where I would want to have the wood stove. The install would go through the roof of the room addition and the chimney would extend up attached to the 2 story brick house for proper drafting.

I see other buildings/cabins that don’t have attics with a wood stove installed. Is the venting sweating a problem and what are others doing to prevent it?

Thank you for any insight that you may have.

I do not know why the installer is concerned about this , the flashing and storm collar are designed to breath / there must be information missing here ,

 

[stoveliker]

This is a cathedral roof, and I believe there should be no air intrusion between the rafters?

The concern is that cold air coming *into* the chimney from the top may result in condensation on the outside of the chimney, in the space between the rafters. That could create wood rot or mold issues.

But, as begreen said, an insulated pipe would not have condensation on its outside when cold air comes in from the top. One more reason to have an insulated pipe.

 

[heiert]

The room for the wood stove isn’t a cathedral ceiling. These are the pictures I sent to the store. Thanks for all the replies. I appreciate the help to understand the sweating pipes.

 

[stoveliker]

Then I don't understand "no attic".
If the pipe goes thru the ceiling, no attic, that's functionally the same as a cathedral ceiling?

Ceiling, rafter space (insulated hopefully), plywood, shingles?

 

[begreen]

The room for the wood stove isn’t a cathedral ceiling. These are the pictures I sent to the store. Thanks for all the replies. I appreciate the help to understand the sweating pipes.

That's what is considered a cathedral ceiling (as opposed to a flat ceiling). The chimney support box looks like this. Sometimes it's called a square support box.

 

[Tonty]

Not to be to much of a nitpicker, but it might be a vaulted ceiling. Cathedral and vaulted have slightly different meanings. If it’s vaulted, there could be a small attic space. Could be a misunderstanding with the OP and term cathedral. Not that it changes anything with the chimney, though….
Reminds me a bit of when I built our house. I built a barn style house with a gambrel roof. I framed what I call a “flying gable” on one end. I mentioned that to a truss designer, and he didn’t know what I meant. Once I explained it to him, he said he preferred to call it a “crow’s beak” because he would hesitate to use the term “flying” with any roof part since the roof might decide to do just that. 🤔

 

[stoveliker]

I'm sure my terminology is off; I didn't grow up here (and there are almost no such roofs where I did).
Point remains the same.
Have an insulated pipe and there won't be any trouble. Not the only install with no or almost no attic.

 

[Tonty]

Have an insulated pipe and there won't be any trouble. Not the only install with no or almost no attic.

Ya, you are right.

 

[jjam]

if you look at the picture begreen ,,posted you can see the slots on the top of the flashing this is for air flow to prevent condensation
then the storm band to prevent rain / the air enters the system under the storm band

 

[begreen]

Not to be to much of a nitpicker, but it might be a vaulted ceiling. Cathedral and vaulted have slightly different meanings. If it’s vaulted, there could be a small attic space. Could be a misunderstanding with the OP and term cathedral. Not that it changes anything with the chimney, though….
Reminds me a bit of when I built our house. I built a barn style house with a gambrel roof. I framed what I call a “flying gable” on one end. I mentioned that to a truss designer, and he didn’t know what I meant. Once I explained it to him, he said he preferred to call it a “crow’s beak” because he would hesitate to use the term “flying” with any roof part since the roof might decide to do just that. 🤔

OK, call it a chapel ceiling.