Due to pressure differences caused by stack e.
Mineral wool insulation around chimney.
The recommended insulation for round chimneys where temperatures are below 300 c is load bearing lamella mats prorox ma 520 alu.
Holes hidden in attics basements and crawlspaces are much harder to locate and usually cause bigger problems.
Fiberglass home insulation is not considered an acceptable fire safeing product.
Once the air seal was accomplished jerome installed a roxul mineral woolinsulation barrier around the chimney.
There was no insulation in the chase before and we decided to go with mineral wool over fiberglass batt insulation which can come with its own integrated vapor barrier.
This isolated the masonry from an r 60 blanket of cellulose insulation that was blown in place after all the airsealing measures were implemented.
However the better method for filling voids in a chimney flue liner to the full height of the flue is to use vermiculite chips can be bought for insulation purposes or as soil treatment check around for best prices.
Thermafiber fire and sound guard mineral wool is thermafiber fire and sound guard mineral wool is designed to provide exceptional acoustic control and fire protection in interior walls as well as floor and ceilings in residential and light commercial construction.
Its density is not high enough and its binder breaks down at less than 400 degrees f.
These are mounted directly onto the chimney and are fastened with straps.