Cellulose as chimney insulation?

[pete97]

I would like to add insulation to my exterior masonry chimney that has a smooth stainless pipe as a liner. I would like to use loose fill insulation since I don't want to pull the pipe and I don't want to use a pour down mix that is permanent. Can I use the cellulose insulation ? The stuff at Home Depot says it is fires resistant and treated with fire retardant. Thanks Pete

 

[mellow]

Pretty sure that would void the warranty on your liner. Pour down mix does not have to be made permanent by adding water, just have a really good block off plate at the bottom.

 

[BrotherBart]

No way! Read this and notice that the stuff starts smoldering at 450 degrees and is difficult to extinguish. Who cares about the warranty on the liner? A chimney full of shredded newspaper will cancel the warranty on your house and or life.

http://inspectapedia.com/interiors/Fire_Characteristics_of_Insulation.pdf

 

[begreen]

Vermiculite or perlite are two insulation materials that can be poured in. Be sure to install a well anchored block-off plate at the bottom first and pack above it with roxul.

 

[bholler]

Straight vermiculite or perlite are no longer recommended due to compression and settling. Use the vermiculite and cement mix it is not permanent it does not set up hard i have pulled a couple liners and then cleaned out the insulation with a rotary cleaner. Those were easier to get out than the one i pulled that was straight vermiculite it was packed in so bad at the bottom the liner didnt want to move i ended up having to unravel it and then use the tile breaker to get out the insulation.

 

[pete97]

I guess that answers my question. The vermiculite is more expensive than buying insulation and pulling the pipe and then wrapping it. Think that is the best option ?

 

[bholler]

It depends on the situation we do both pour in and wrap depending on which makes more sense in that situation. But regardless do not use straight vermiculite. And absolutely do not use cellulose you will burn your house down

 

[firefighterjake]

Fire resistant is not the same as fire proof or non-combustible . . . echoing here . . . do not use cellulose . . . unless perhaps you might like to meet the men and women at the local fire station . . . at 2 a.m. . . . in your living room.

 

[check212]

Roxul