Advice needed for passthru

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tlhfirelion

Feeling the Heat
Aug 6, 2007
442
so I'm preparing to add a passthru in my ceiling straight up and out as I'm redoing my chimney. I'll list what all I think I need below and if y'all could review that and tell me if I'm missing anything that would be awesome. I'm having to milk the old century another winter but next winter I'll have a Woodstock stove!

So, I already have 3-3' sections of 2100 degree pipe as well as the rain cap.

I think I need the following in order of appearance as I work my way up,

A) single wall inside from stove to ceiling (5')

B) ceiling support box

C) attic insulation shield

D) pitched roof flashing

Then I'll add the 9' of pipe I already have and the cap. It's a 4/12 pitched hip shingle roof and I'm close to the edge by about 3'. I assume I'll also need a support bracket to hold the exterior pipe to the house as well, correct? It'll be roughly 15' from stem to stern which I believe is enough. I wonder if I can get away with only using 2 of the 3 sections of pipe above the roofline? My clearances are ok.

Am I missing anything? Thank you in advance for the assistance.
 
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My stove supplier suggested double wall pipe the entire way. the idea was you do not want to lose too much heat in the chimneynor you may have draft problems. I am glad I did it because the double wall still gets quite warm and does pass plenty of heat into the room. I am afraid if I had gone songle wall you would not be able to go near it.
 
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so I'm preparing to add a passthru in my ceiling straight up and out as I'm redoing my chimney. I'll list what all I think I need below and if y'all could review that and tell me if I'm missing anything that would be awesome. I'm having to milk the old century another winter but next winter I'll have a Woodstock stove!

So, I already have 3-3' sections of 2100 degree pipe as well as the rain cap.

I think I need the following in order of appearance as I work my way up,

A) single wall inside from stove to ceiling (5')

B) ceiling support box

C) attic insulation shield

D) pitched roof flashing

Then I'll add the 9' of pipe I already have and the cap. It's a 4/12 pitched hip shingle roof and I'm close to the edge by about 3'. I assume I'll also need a support bracket to hold the exterior pipe to the house as well, correct? It'll be roughly 15' from stem to stern which I believe is enough. If I can get away with not using all three sections of pipe above the roofline, that would be nice. I think I could get away with not using a supoort bracket, could I not?

Am I missing anything? Thank you in advance for the assistance.
My stove supplier suggested double wall pipe the entire way. the idea was you do not want to lose too much heat in the chimneynor you may have draft problems. I am glad I did it because the double wall still gets quite warm and does pass plenty of heat into the room. I am afraid if I had gone songle wall you would not be able to go near it.

Thanks for the reply. I've had single wall for many years and it really does get warm but I liked that I was getting the extra heat as opposed to just sending it up the pipe. I'm going from a chimney that had an elbow, wall thimble and a T to a straight shot up and out so I'm assuming (maybe incorrectly) that my draft will only improve (not that I ever had any issues with the previous set up drafting) I've not priced the double wall so I wonder if it's as expensive as the other HT pipe? Thank you for the reply!
 
Thanks for the reply. I've had single wall for many years and it really does get warm but I liked that I was getting the extra heat as opposed to just sending it up the pipe. I'm going from a chimney that had an elbow, wall thimble and a T to a straight shot up and out so I'm assuming (maybe incorrectly) that my draft will only improve (not that I ever had any issues with the previous set up drafting) I've not priced the double wall so I wonder if it's as expensive as the other HT pipe? Thank you for the reply!

I would think then you would be improving your draft but also make sure your distance is good, I think folks suggest at-least a total of 14 feet from the stove top. I would be nervous passing single wall through combustibles even with a spacer box and don't forget clearances from the single wall to the ceiling/surrounds.
 
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hi there,......if you havn't bought that roof flashing yet have a look for a stainless steel one. I got mine together in 2008 if I remember correctly and the metal is rusting and will need to be changed at some point in the future.... rn
 
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I would think then you would be improving your draft but also make sure your distance is good, I think folks suggest at-least a total of 14 feet from the stove top. I would be nervous passing single wall through combustibles even with a spacer box and don't forget clearances from the single wall to the ceiling/surrounds.

I am roughly at 15' or so from the top of the stove to the rain cap so it sounds like I am good to go height wise. You make a good point about the clearance to the ceiling so I'll take a look at the double wall. Thanks!
 
hi there,......if you havn't bought that roof flashing yet have a look for a stainless steel one. I got mine together in 2008 if I remember correctly and the metal is rusting and will need to be changed at some point in the future.... rn

Thats some good feedback there and the top elf stuff I had hoped to get from my post here, thank you. I hope the stainless isn't too much more expensive than the galvanized.
 
I haven't bought anything yet, I want to make sure my list of items needed is complete before posting and I've added the stainless roof flashing to the list.
hi there,......if you havn't bought that roof flashing yet have a look for a stainless steel one. I got mine together in 2008 if I remember correctly and the metal is rusting and will need to be changed at some point in the future.... rn
 
I would be nervous passing single wall through combustibles even with a spacer box and don't forget clearances from the single wall to the ceiling/surrounds.

i'm pretty certain that you can't by code pass single walled pipe through a combustible wall / ceiling. It has to transition to Class A pipe from there on up.
 
i'm pretty certain that you can't by code pass single walled pipe through a combustible wall / ceiling. It has to transition to Class A pipe from there on up.

I would call your county inspectors office, they are more then happy to answer questions where I am. I e-mail them so I have a written record of what they tell me. They may just tell you to follow the manufacturers requirements, in which case you should be able to find out minimum clearances from the seller for the single wall pipe. I think it is at least a foot and a half. Of course if you are insulating the wall then you are ok, but would want double wall closer to the ceiling unless your going to have 18 inches of box hanging down.
 
I would call your county inspectors office, they are more then happy to answer questions where I am. I e-mail them so I have a written record of what they tell me. They may just tell you to follow the manufacturers requirements, in which case you should be able to find out minimum clearances from the seller for the single wall pipe. I think it is at least a foot and a half. Of course if you are insulating the wall then you are ok, but would want double wall closer to the ceiling unless your going to have 18 inches of box hanging down.
NFPA my friend, going through the ceiling starting at the stove collar - single wall pipe must be not closer than 18" from a combustible wall, installing the ceiling support box leaving a minimum 2" of box hanging below the ceiling line, terminate the single wall pipe with adapter on bottom side of support box, on the top side of ceiling support box install double wall insulated class A chimney, insulation shield, then go through the roof, using proper through the roof kit, go high enough for the 2-3-10 rule, add no restrictive chimney cap and any appropriate bracing on lengths greater than 5ft (don't for get to caulk any seems on class a pipe or weather shield)
 
What is the 2-3-10 rule
 
I think we are getting a bit away from my initial question. I'm out in the sticks so my counties answer to my questions was literally, 'We ask that you do it right". lol OK, well I do want to do it right and I don't want to burn my house down so, setting aside the issue of the single vs double wall interior pipe, do I have the correct items to pass thru the ceiling/roof? I want to make sure that I do that absolutely correct and even overdo it a bit if I have too. Thank you for the feedback.
 
hi there,......if you havn't bought that roof flashing yet have a look for a stainless steel one. I got mine together in 2008 if I remember correctly and the metal is rusting and will need to be changed at some point in the future.... rn

It would seem that aluminum would be just as rust resistant as SS and both would be leaps better than galvanized, would you agree?
 
It would seem that aluminum would be just as rust resistant as SS and both would be leaps better than galvanized, would you agree?
Rust resistant yes but corrosion resistant no. Aluminum will not last long at all.
 
Rust resistant yes but corrosion resistant no. Aluminum will not last long at all.
Stainless it is. :) Thank you. If you look at my list from my initial post, am I missing anything to pass thru my ceiling safely? Would i need a rook support bracket for 2 sections of high temp exterior pipe? Thank you
 
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