hi. I am in the middle of having a Travis Industries large flush wood insert installed into an existing prefab ZC fireplace (just waiting for surround panel to be custom cut).
The manual states, “ to prevent air from passing up the ZC fireplace chimney (the gap between the liner in the chimney) we recommend sealing the area near the damper. Use non-combustible material to seal this area (non-backed fiberglass insulation or kaowool).”
This is an interior chimney.
I’ll check with the installer, too, but I assume the experts here think closing off this gap is a “must-do”?
Also, opinions on plain old non-backed fiberglass insulation vs kaowool?
thank you
![[Hearth.com] Insulation where new liner enters existing chimney](https://www.hearth.com/talk/data/attachments/300/300898-f9bb2dda6d78d6c6c6dee4e62b51d0da.jpg?hash=dOxYKlbAul "[Hearth.com] Insulation where new liner enters existing chimney")
The manual states, “ to prevent air from passing up the ZC fireplace chimney (the gap between the liner in the chimney) we recommend sealing the area near the damper. Use non-combustible material to seal this area (non-backed fiberglass insulation or kaowool).”
This is an interior chimney.
I’ll check with the installer, too, but I assume the experts here think closing off this gap is a “must-do”?
Also, opinions on plain old non-backed fiberglass insulation vs kaowool?
thank you
![[Hearth.com] Insulation where new liner enters existing chimney](https://www.hearth.com/talk/data/attachments/300/300922-5e8e24c00d17dfabc019e9f92dfe0a57.jpg?hash=RocRASnHBV "[Hearth.com] Insulation where new liner enters existing chimney")
