Single Wall Pipe - Distance to Combustibles

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Kwehme09

Member
Sep 7, 2011
76
Northern N.H.
Hi All,

I am converting an old building into a Maple Sugar house. It will have a wood-fired evaporator (with blower) vented with 10" stainless steel single wall stove pipe. I expect some pretty darn high flue gas temps; it's basically the idea with an evaporator. The roof of the building is framed with trusses, 24" o.c. The nature of this setup makes it so that the stovepipe passes about 6" from the 2x4 truss members in a few spots, which is too close for my comfort. Any suggestions on a solution?

- Attach ceramic fiber insulation to the trusses where the pipe passes closely by?
- Fab up small heat shields to attached to the trusses at the questionable points?
- Combination of the above too?
- I already have all the single-wall pipe, but should I buy a few short pieces of double-wall pipe for the trouble spots? Can I go back and forth from single to double-wall? I'd say this is my least preferred choice, but I'd obviously do it if it means not burning the place down.

These evaporators don't come with the same specs as a woodstove, so there is a bit more McGyvering involved. I know this isn't exactly a hearth question, but it's all the same principals. Any thoughts?
 
We ran a 10 exhaust glue with or evaporator up through the roof like you. The temperatures are extremely high, like you know, double wall and as much clearance as possible. We also filled in the remaining space to the rafters with rock wool insulation . Make the hole through the roof as big as possible and use a metal roof. We had a blow torch coming out of the chimney, we switched to oil last year, which is more user friendly , but more expensive.
 
"Really high temps" doesn't describe the situation. What are the manuf recommendations on the equipment. Is this a negative pressure flue or positive? The positive pressure commercial venting may be what you need, but you have to tell us.
 
Our flue temps were always 800F , at times at the back of the evaporator we would see the pipe glow a dull red.
 
Hi All,

I am converting an old building into a Maple Sugar house. It will have a wood-fired evaporator (with blower) vented with 10" stainless steel single wall stove pipe. I expect some pretty darn high flue gas temps; it's basically the idea with an evaporator. The roof of the building is framed with trusses, 24" o.c. The nature of this setup makes it so that the stovepipe passes about 6" from the 2x4 truss members in a few spots, which is too close for my comfort. Any suggestions on a solution?

- Attach ceramic fiber insulation to the trusses where the pipe passes closely by?
- Fab up small heat shields to attached to the trusses at the questionable points?
- Combination of the above too?
- I already have all the single-wall pipe, but should I buy a few short pieces of double-wall pipe for the trouble spots? Can I go back and forth from single to double-wall? I'd say this is my least preferred choice, but I'd obviously do it if it means not burning the place down.

These evaporators don't come with the same specs as a woodstove, so there is a bit more McGyvering involved. I know this isn't exactly a hearth question, but it's all the same principals. Any thoughts?
Get doublewall insulated chimney pipe for through the roof
 
Get doublewall insulated chimney pipe for through the roof

Through the roof is definitely not my closest point to combustibles. It's a metal roof with no ceiling, sheathing or strapping near the opening. I am less worried about the roof penetration.
 
Through the roof is definitely not my closest point to combustibles. It's a metal roof with no ceiling, sheathing or strapping near the opening. I am less worried about the roof penetration.
I was assuming it was just open with just roof framing. If there is other framing or a ceiling start the chimney there