Venting Challenge

[BillyReaver]

Hi! I need some advice. I am setting up a new Wood Stove install. The challenge is shallow roof pitch so owner doesn't want anything to go through the roof. There are 2 levels of the house a taller section with a 14' ceiling and the other part w 10' ceiling. the stove is going in the `14 section.

option 1. Ideally would like to go straight up from stove into ceiling support box and then hard turn and go out side wall of 14 ft section over the 10ft section and up from there, but haven't seen anywhere a 90 or close to 90 turn in the ceiling, so i guess that's not done.

option 2. have a long stove pipe on the inside that has to go up but also a fair amount horizontally to clear the rise of the 10ft roof truss and the out through normal wall thimble. but on outside need to kick out to clear the 2ft roof overhang.

is the resistance to 90 turns fear of creosote? I see them a lot on the inside. and i guess a wall thimble has one tee.
thanks!

 

[bholler]

Hi! I need some advice. I am setting up a new Wood Stove install. The challenge is shallow roof pitch so owner doesn't want anything to go through the roof. There are 2 levels of the house a taller section with a 14' ceiling and the other part w 10' ceiling. the stove is going in the `14 section.

option 1. Ideally would like to go straight up from stove into ceiling support box and then hard turn and go out side wall of 14 ft section over the 10ft section and up from there, but haven't seen anywhere a 90 or close to 90 turn in the ceiling, so i guess that's not done.

option 2. have a long stove pipe on the inside that has to go up but also a fair amount horizontally to clear the rise of the 10ft roof truss and the out through normal wall thimble. but on outside need to kick out to clear the 2ft roof overhang.

is the resistance to 90 turns fear of creosote? I see them a lot on the inside. and i guess a wall thimble has one tee.
thanks!

Tell them you need to go straight up through the roof.

 

[stoveliker]

There are no 90 deg chimney pipe elbows anyway. So once you get through the ceiling box, all. you can do is go up (okay, there are 30 degrees offset jogs, but that's it).

Straight up will make the stove run better anyway, especially with a flue that is only 16 ft or so tall...

 

[BillyReaver]

Tell them you need to go straight up trough the roof.

Well, i appreciate the response, but most people like to have a little explanation when you tell them they need to change their plans

 

[BillyReaver]

There are no 90 deg chimney pipe elbows anyway. So once you get through the ceiling box, all. you can do is go up (okay, there are 30 degrees offset jogs, but that's it).

Straight up will make the stove run better anyway, especially with a flue that is only 16 ft or so tall...

Most out of wall vents i see have a 90 over the stove to go to the thimble and then there is a Tee outside that point the chimney pipe up. Those seem to draw fine. I have a similar set up in a pole barn and it rips. has maybe 18 of height, 6 inside and 12 outside

 

[bholler]

Well, i appreciate the response, but most people like to have a little explanation when you tell them they need to change their plans

The solutions suggested in your post would be almost unserviceable and would seriously compromise draft. There is no reason to complicate what should be a simple through the roof install.

 

[stoveliker]

The reasons are 90s are not possible in chimney pipe.

How tall would this be from stove top to 2-3-10 rule adherent cap?

 

[BillyReaver]

The solutions suggested in your post would be almost unserviceable and would seriously compromise draft. There is no reason to complicate what should be a simple through the roof install.

There is a reason.. Flat roofs leak more because the water is more likely to sit and puddle . too late to argue against flat roof

 

[BillyReaver]

The reasons are 90s are not possible in chimney pipe.

How tall would this be from stove top to 2-3-10 rule adherent cap?

doing the ceiling option. it would be 13 ft from stove to ceiling- straight and then the 90 turn in the ceiling and 2ft through a truss to get out of the sidewall, another 2 ft outside to clear overhang, then 90 to go vertical, vertical section would only need to be about 6-8 ft to be 2ft higher than peak, so total height would be about 18-20 ft with 2 90 degree turns and 3-4 ft running horizontal

 

[bholler]

There is a reason.. Flat roofs leak more because the water is more likely to sit and puddle . too late to argue against flat roof

What type of roof is it?

 

[BillyReaver]

standing seam 1/12

 

[bholler]

standing seam 1/12

Yeah just go through the roof 1/12 is plenty of pitch. The only other option that is feasible is to go 2' up off the stove then out but you will need to add quite a bit of height to overcome the 2 90s and pretty long horizontal run.

 

[all night moe]

I vote for straight up and out the roof. It beats going through the wall at the stove, in performance, all day.
I love standing seam. Best roof available, hands down, and understand the wanting of not disturbing it.
This said, through the roof, will make any stove choice perform at it's optimum.

 

[BillyReaver]

Yeah just go through the roof 1/12 is plenty of pitch. The only other option that is feasible is to go 2' up off the stove then out but you will need to add quite a bit of height to overcome the 2 90s and pretty long horizontal run.

Thanks for the clarification, i appreciate it

 

[John Galt]

I would study the codes before submitting a bid for this work. When you go through the ceiling you have to transition from stove pipe to Class A chimney pipe. There are no 90 degree elbows in chimney pipe. Your options are straight up through the roof or move the stove location.

Then the roof is an issue. Most metal roof manufactures require/recommend a 3:12 pitch. There are some that allow less pitch if it is a mechanically locked seam. Any work done on the roof (holes, flashing, etc.) opens you up to the liability of a leaking roof. Be careful with this one.

 

[BillyReaver]

I would study the codes before submitting a bid for this work. When you go through the ceiling you have to transition from stove pipe to Class A chimney pipe. There are no 90 degree elbows in chimney pipe. Your options are straight up through the roof or move the stove location.

Then the roof is an issue. Most metal roof manufactures require/recommend a 3:12 pitch. There are some that allow less pitch if it is a mechanically locked seam. Any work done on the roof (holes, flashing, etc.) opens you up to the liability of a leaking roof. Be careful with this one.

Thanks for the reply

 

[BillyReaver]

"There are no 90 degree elbows in chimney pipe."
Why is that? in ability to clean?

 

[all night moe]

"There are no 90 degree elbows in chimney pipe."
Why is that? in ability to clean?

Never manufactured.
Stove pipe and chimney pipe, (class A), are 2 different things.

 

[BillyReaver]

Never manufactured.
Stove pipe and chimney pipe, (class A), are 2 different things.

I understand, but curious as to why it is no problem to have 90s inside, but they can't be outside. Also the Duravent Thimble seem to have a 90. Just wondering what the reason is.

 

[all night moe]

I understand, but curious as to why it is no problem to have 90s inside, but they can't be outside. Also the Duravent Thimble seem to have a 90. Just wondering what the reason is.

Stove pipe does not belong outside.
90s are not made in class A chimney. Clean out Ts are the exception.

 

[John Galt]

Just wondering what the reason is.

That would be something the manufacturers would have to answer. A stove pipe has to be accessible so you can see if there is an issue with an elbow. The chimney pipe can be inside a sealed chase, if there was an elbow inside that chase and fails it would go unnoticed until... fill in the blank.

 

[BillyReaver]

That would be something the manufacturers would have to answer. A stove pipe has to be accessible so you can see if there is an issue with an elbow. The chimney pipe can be inside a sealed chase, if there was an elbow inside that chase and fails it would go unnoticed until... fill in the blank.

ok thank you

 

[bholler]

"There are no 90 degree elbows in chimney pipe."
Why is that? in ability to clean?

Yes it would not be serviceable. Even 45s are not allowed 30 is the hardest angle allowed by code. That is also the reason you don't want to go through the wall to high. That pipe needs pulled apart every time it's cleaned. If it's to high outside and inside it will be a huge PITA.