packed Roxul...a fire hazard?

[mattmania]

Hey guys,

Just wondering if packed Roxul rockwool could be a fire hazard. I have a ton of old 6 inch thick roxul insulation and have an old exterior wall with a 4 inch cavity (old 2x4 frame, which really is 2 by 4 inches). How bad is it if I just compressed the roxul and squeeze it in there...this is a section of wall which will be behind my wood stove, so if this at all screws with the heat resistance of the wall, I rather of course not take a chance.

Any quick thoughts?

 

[bholler]

Well if it is wood framed it really doesnt matter what you do it is still a combustible wall.

 

[scivi92]

The roxul I have which is new, is rated to 2100 degrees so it wouldn't burn, not sure what you're older roxul is rated at. I do know that it's bad practice to compress insulation and that it should instead be cut to size and layers peeled off to reduce it's thickness. If I knew the temperature rating of your Roxul was about as high as mine, I'd peel it down to four inches thick and install it.