Can I insulate a flexi liner with a ceramic blanket?

[lizkehl]

I am installing a flexi chimney liner into an existing masonry chimney. The chimney is lined already with clay tile (it looks to be in good shape but hard to tell so we are using a stainless steel flexi liner kit), however the clay liner stops right at the pitch of the roof and the unlined brick chimney is another 14" to the opening. I would assume the flexi liner would need to be insulated on this 14" section, but it doesn't makes sense for me to buy an entire roll of insulated liner since the chimney is central and there is a pre existing clay liner. I should also note its a VERY tight fit leaving very little room for liner. Should I use pour in insulation? If so could I use a screen or a piece of metal to stop the pour in insulation from going down the entire flue? The stove being put in is a jotul F100 QT with double wall stove pipe into an insulated thimble. The chimney is center of the house in the living room straight up to the roof. I would guess where the clay liner stops is where the flexi liner should be insulated? Any help would be greatly appreciated!

 

[bholler]

I am installing a flexi chimney liner into an existing masonry chimney. The chimney is lined already with clay tile (it looks to be in good shape but hard to tell so we are using a stainless steel flexi liner kit), however the clay liner stops right at the pitch of the roof and the unlined brick chimney is another 14" to the opening. I would assume the flexi liner would need to be insulated on this 14" section, but it doesn't makes sense for me to buy an entire roll of insulated liner since the chimney is central and there is a pre existing clay liner. I should also note its a VERY tight fit leaving very little room for liner. Should I use pour in insulation? If so could I use a screen or a piece of metal to stop the pour in insulation from going down the entire flue? The stove being put in is a jotul F100 QT with double wall stove pipe into an insulated thimble. The chimney is center of the house in the living room straight up to the roof. I would guess where the clay liner stops is where the flexi liner should be insulated? Any help would be greatly appreciated!

The existence and condition of clay liners has nothing to do with insulation requirements. It's all about clearance to combustibles between the outside of the masonry structure and any combustible material. In your case with an internal chimney you need 2" if you don't have that your chimney doesn't meet code and requires an insulated liner.