Increasing insulation on double wall stove pipe
SBFrCBwRnK
| Posted in Building Code Questions on
My wood stove’s double wall insulated stove pipe goes from the first floor through the second, into the attic, and out the roof. The pipe radiates enought heat into the attic to melt snow on the roof and form ice dams at the eaves. What can I do to reduce the heat into the attic? Can you wrap the double wall pipe with insulation without making a fire hazard?
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Replies
No. Contact the pipe manufacturer for what they allow or to see if any solution exists that would pass their scrutiny.
Greg, is the melting and ice dam formation widespread or local to where the chimney passes through the roof? What length of chimney is exposed in the attic? Is the roof penetration down low, up near the ridge, or more in between? If the melting is widespread, then I have to wonder if there is adequate soffit and ridge ventilation of the attic.
I would frown on wrapping the chimney with additional insulation without mfg approval, as AJ suggests, because that would alter the temperature profile across the chimney wall, bringing the metal sheathing outside the pipe insulation a lot closer to flue gas temperature. What you might think about is running that section of chimney in the attic through a large diameter single wall pipe section as an attic chase. If you have, say, 6" chimney, with 8" OD, then use perhaps a 12" outer pipe, right up to the roof line.
I have a similar chimney route configuration, although in my case the roof penetration is fairly close to the lower edge of the roof, so that the length of exposed chimney in the attic space is minimal. There is a little melting at times, but it is local to the chimney.