How to use Vermiculite?

[alfrehner]

I have been exploring different ways to insulate my chimney liner that I just installed. No room for a blanket so I guess my only other option is the pour in type. I have heard that you can use vermiculite, but I was unsure how to use. I have been told you can just pour in the vermiculite powder, or you can mix it with cement and pour it in. Anybody messed with this stuff, or should I explore other options. Thanks

 

[Todd]

Another option is to just stuff rock wool or koa wool insulation into the top couple feet inbetween the liner and old chimney liner. This will create an insulating air space keeping the liner warm.

 

[jlow]

I built a brick pizza oven and used vermiculite as a heat insulator. I mixed it with firebrick mortar and used it with a form. I will try and find some photos. It has worked well.

 

[Wet1]

Another option is to just stuff rock wool or koa wool insulation into the top couple feet inbetween the liner and old chimney liner. This will create an insulating air space keeping the liner warm.

This will indeed keep the chimney a little warmer, but I don't know that it's any safer. If you need ZC because or your construction or if your chimney is in poor condition, you need insulation all the way down the flue. While I know vermiculite is very safe for this application, I don't know if it meets code or not. Talk with your inspector if this is a concern.