Insulation

[dakotarnk]

Can the fiberglass insulation that one would put in the walls without the paper backing be put against class a chimney pipe. If not what do you use.
Thanks

 

[nshif]

NO! Thats why there is an insulation shield on the ceiling box. If you need to insulate class A chiminy you will need something like kaowool. Im sure there are other products and others will chime in. My only question is why do you need to insulate it? Is it a liner?

 

[dakotarnk]

Its not a liner, I am installing a class a and where it goes through the roff I wood like to install some insulation.

 

[KeithO]

The fiberglass itself will not burn, but virtually all fiberglass made has "sizing" on it, which is a type of wetting agent, and that will burn.

Why do you want to insulate it ? You know of course that the class A has at least 1/2" of ceramic insulation between the inner and outer wall ? If you must insulate, use cement board at least 2" away from the class A and then add whatever insulation you want on the outside of that.

 

[elkimmeg]

In order for class A pipe to work as it should it requires 2" air space to dissipate heat If you fill that space in you stop dissipation and build up too much heat in the Class A pipe too much heat is another formula for undesirable results and consequences