Thermix Liner Insulation Removal

[Atomic1]

30' tall exterior masonry chimney with an 8" square clay liner. The upper portion of the liner is getting iffy (deteriorated) and my draft is not all that great in the winter, so I'm looking at SS liners. My sweep is recommending a 5.5" SS liner placed into the existing clay flue, and insulated with Thermix. My main concern is when the SS liner eventually needs to be replaced. There seems to be very little information on the removal of poured insulation. Has anyone come across this?

Then there's the question of how they can center the SS liner when trying to shove this thick insulation down between the SS liner and clay liner.

 

[Rickb]

Why not just get a 5.5 liner with a insulated wrap on it?

 

[Atomic1]

The sweep says its impossible to install a 5.5" liner with a wrap into an 8" square liner.

 

[begreen]

The only way they could keep it from touching the walls it as it goes down the chimney would be with spacers at regular intervals and that is not guaranteed, but it won't be worse than burning directly connected to the current 8" liner.

 

[Ctwoodtick]

I’m not a pro, but have learned a lot from this site . Does your stove/insert allow for 5.5 inch liner? Check with the manufacturer on that one. You could choose to break out old clay liner and then you have the room to wrap insulate your liner at the correct diameter (I’m assuming 6”). A heavy wall ss liner would give you more longevity than the light wall ones while being more durable overall. If you went that route, you may not have to think about replacing it (or the thermix), and you’d have a much better set up (probably for the same amount of money over time...just a bit more upfront. The pros will chime in if this info is bad.

 

[bholler]

There is not enough room inside an 8x8 for a 5.5 liner with the required 1" of insulation on all sides. The clay needs to be removed.

And pulling a liner with thermix isnt a big deal.