Insulating the chimney

[fireview2788]

I asked my chimney guy about a block off plate and he recommended that instead of a plate that I stuff standard fiberglass insulation, with the paper removed, up there. He said the only time he has seen the stuff even melted a little was the result of a chimney fire. I went to Lowes and everything I found said not to put closer than 3" from steel chimney pipe. Is there a heat rated insulation? What do you guys think?


fv

 

[rjmorrow]

I would find a new chimney guy...

 

[Rob From Wisconsin]

Wouldn't use normal fiberglass insulation.
You could use Roxul, they have that a Lowe's.
I don't know if it would have enough tensile strength
to keep from falling apart, but it would be fireproof.
I would use it although with a block-off plate.......

 

[northernontario]

2nd... Roxul (rock wool) has a very high heat resistance (2150°F according to their website... http://www.roxul.com/stone+wool/fire-resistance). But, like any fiber-based insulation, Roxul is still going to allow airflow through it. A blockoff plate can be sealed up with high-temp silicone to seal out air infiltration.

 

[pen]

here is a link to what someone else on the forum did recently https://www.hearth.com/econtent/index.php/forums/viewthread/78544/

pen

 

[fireview2788]

I saw that stuff and figured it would be the best stuff. I'm not mechanical in any fashion so creating my own block-off plate is out of the question.


fv

 

[Milton Findley]

For what it is worth, if I ever have to replace my liner I will dispense with the block off plate, the heat that escapes my old fireplace merely heats up the triangular space behind the stonework and keeps the chimney chase warm and the the draft going.

I will simply take a broom handle and stuff Roxul up into the space between the liner and the old flue, and I will stuff enough of it up there that there will be absolutely no meaningful air flow around it.

The opening to my fireplace is blocked behind my stove, so there is minimal air flow in that direction anyway.