[Greenbuilding] air sealing a metal fireplace flue

[Frank Tettemer]

Hi all,

Kermit's point is well taken. Ask your Code enforcement officer.
In addition, the other source to inquire with is the Chimney 
Manufacturer.  Each chimney maker has their own, fire-tested details 
that need to be followed precisely, in order to assure safety.

For example, many chimneys, including Selkirk, Excel, and Security all 
require NO Insulation of any kind to surround the exterior of the outer 
metal of the chimney.

The reason is that if there is added insulation, the temperature of the 
metal in the chimney parts will be increased by the existance of this 
additional insulation. This can cause the inner steel lining to be 
hotter than the design temperature, and cause metal fatigue and 
subsequent failure.  The manufacturers all must pass certain burn tests, 
to receive their safety sticker, and these tests are nearly always done 
with air movement allowed around the outside of the chimney.

Even that annoying area, where the chimney passes through the roof frame 
and sheathing, underneath the domed roof flashing area, usually must be 
insulation-free. Consult the installation manual of the brand and type 
of chimney you plan to use, before solidifying your plans.

Frank Tettemer
Living Sol ~ Building and Design
www.livingsol.com

> Insulation in contact with the pipe is verboten.

*Flammable insulation* or all insulation?  Ask your Code enforcement 
officer.

Thank You Kindly,

Topher Belknap

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