Question about exposed stove pipe on new install

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joefrompa

Minister of Fire
Sep 7, 2010
810
SE PA
Hi all:

I've tried to find my answer through general searches, so forgive me if these are easy questions and I just couldn't answer them to my satisfaction.

I have a new green mountain 60 installed in my newly built home - just installed by the selling company, a reputable spot in southeastern PA. The stove pipe exiting the top of the stove is a double wall type to enable us to get as close to the wall as possible but otherwise is standard black stove pipe entering into a ceiling box where it becomes class a double walled chimney.

My questions are on the stove pipe install. Specifically (see pics)

The stove pipe shows 4 seams between the stove and the ceiling (~6' above the stove). The seams are as follows from the stove to the ceiling:

- At the stove flange where the pipe slips over the stove exhaust (makes sense to me)
- ~8" above the flange there's another seam - maybe where a connecting piece ends? I'm ok with this I think though I don't know why it needs to exist.
- ~30" above THAT there's a seam as if one piece of black stove pipe is being inserted into another. This is what I don't understand. Further, at this seam there's a gap as if the stove pipe metal is very thin and flexible and it's not seated between the top and bottom pieces perfectly flush.
- Last seam is where it hits the ceiling.

To me, this doesn't seem right. It's a 6' section. To me an ideal install would be a single piece of black double with a seam connection at the stove and the next at the ceiling. The stove has a standard 6" outlet, so i'm unsure why a flange is needed between the stove exit and the exhaust - but I'm not an expert. The seam in the middle of the pipe with a gap in it doesn't look right at all.

Checking with the forum - does this look correct or incorrect? On a side note, during the pre-install measurements we agreed to route the outside air intake down through the floor and out through the band board and we were discussing a plain black steel hearth pad or stone/tile underneath. We went with the plain steel pad supplied by the same company and now they are unsure about drilling through it. Lol. :)

Stove Pipe flange jpg.jpg Stove pipe flang 2 jpg.jpg
 

joefrompa

Minister of Fire
Sep 7, 2010
810
SE PA
P.s. we had the ceiling box powder coated white to blend in better with the ceiling. Super happy with how that came out. Right now the drywall is abutting the ceiling box in rough edge, not sure yet the plan to properly cover that/trim over that to make it look properly finished.
 

stoveliker

Minister of Fire
Nov 17, 2019
6,165
Long Island NY
That is likely a telescoping piece intended to make it easy to remove the stove pipe for cleaning.
 

joefrompa

Minister of Fire
Sep 7, 2010
810
SE PA
That is likely a telescoping piece intended to make it easy to remove the stove pipe for cleaning.
Are such telescoping pieces semi-loose/thin sheet metal on the outside that has small gaps between pieces? This piece has about a 1/4" gap where the pipe was rotated to face away from the room (i.e. you can only see the gap from the back-side of the stove).
 

stoveliker

Minister of Fire
Nov 17, 2019
6,165
Long Island NY
It happens. It's double wall, the internal one will likely be closer (smaller gap).
One could add a sheet metal screw if it bothers you, but generally it's not a big deal unless you hear air rushing in.
 

joefrompa

Minister of Fire
Sep 7, 2010
810
SE PA
Thank you. Sounds like a (small) price to pay for use a cat stove where you can't run a brush up through the cat easily, and therefore a telescoping pipe and more desirable for maintenance purposes.
 

stoveliker

Minister of Fire
Nov 17, 2019
6,165
Long Island NY
Some (most?) cat stoves can run a brush up through the bypass. But it's nice to be able to get things apart regardless. Not being able to shorten a section means bending things. Then putting things back would be problematic. I think most stoves have such a telescoping piece in the stack for this reason.

Again, if you have clear evidence of air rushing in when you burn, call your dealer to assess and possible correct.
 

joefrompa

Minister of Fire
Sep 7, 2010
810
SE PA
It's installed now but i'm days away from a burn (build still underway) as the chimney is also being finished/capped and the builder needs to clear running a live fire in a house under construction. The installers didn't put a shield around the stove pipe in the attic, letting blown in insulation sit right against the double walled class A pipe as well - so that needs to be fixed to give proper air space. Just a few things before I think I'll be ok'd to run my first stove and begin break in.
 
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stoveliker

Minister of Fire
Nov 17, 2019
6,165
Long Island NY
yes. Good catch about the attic. (There are more knowledgeable folks here than me; if you post some pics of the whole system up to the ceiling, in the attic, and above the roof, you may get further feedback - and if issues are seen it's easier to fix them now then half a year from now, with contractors still around.)
 

MMH

Minister of Fire
Jan 21, 2019
604
NV
As mentioned @stoveliker the first piece is usually telescoping. Maybe @bhollar can chime in but usually the first piece is telescoping regardless of stove, to simply make the first connections easier etc. cat stoves (most) can have a brush run up them regardless of the telescoping piece. Good catch on the attic
 

begreen

Mooderator
Staff member
Nov 18, 2005
96,219
South Puget Sound, WA
The first piece is the appliance adapter. This is necessary on some stoves for a proper fit at the flue collar. The rest of the stove pipe is telescoping as noted. Can you verify that double-wall stovepipe was used? It looks like it might be DuraVent DVL, but it would be good to be certain that double-wall was used. This also affects clearances.
 
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joefrompa

Minister of Fire
Sep 7, 2010
810
SE PA
I can confirm I spec'd double wall in order to get minimum clearances. How can I confirm by looking at it whether it's double wall or not?

I'll give credit on the chimney as well...I have access to it between the 1st and 2nd floors and in the attic. That is one solid piece of tubing. They also installed as a gas stove for me and did a good clean install.
 

begreen

Mooderator
Staff member
Nov 18, 2005
96,219
South Puget Sound, WA
Is there a label on the pipe or the appliance adapter? That will have the product info.
 

stoveliker

Minister of Fire
Nov 17, 2019
6,165
Long Island NY
You can also measure the outside circumference. A single wall 6" pipe will be near 19". A double wall will be near 20.5".
 

vatmark

Burning Hunk
Jan 5, 2017
129
Nebo NC
We have a lot of seams as well. Our stove pipe is double walled and telescoping which allows us to remove it for cleaning.

11311702-288A-467F-9E60-20567E08DAE4.jpeg