Sealing off around liner at the flue what is proper insulation?

[reed102]

I'm installing a wood burning insert into our existing fireplace which contains a "heat-a-lator clone made by Superior Furnace. It was here when we bought the home and found it to be a total waste. I will have to cut out one of the steel tubes to get the liner thru but at least I won't have to tear out a bunch of steel. I running a 6" stainless liner and have read that I will need to seal off the area around the liner as it goes into the flue. I don't know what type of insulation I should use around this. Is regular firberglass insulation sufficient?

 

[kd460]

No to the fiberglass isulation. It can't handle the heat. A product cal kaowool, or ceramic insulation (refactory insulation) and a block of plate needs to be used at the top of the liner where it exits the chimney and at the fireplace where enters the firebox. I have read that mineral wool or rock wool will work, but not sure. Definetely koawool will work, and a stainless steel block of plate would be best (with stove sealant-not silicone sealant). Do a search on those terms and you will find better info than I can provide.

Here is a nice link on the heat resistence of some diffferent types of insulation:

http://www.procureit.com.au/thermal.html

Good luck, KD

 

[webbie]

In general, insulation is not used to seal the damper or bottom area. You want to use a sheet metal block-off plate, and it just so happens that I wrote instructions on how to do this.

https://www.hearth.com/econtent/index.php/articles/making_a_block_off_plate/

As per article, 24 ga galv. metal is fine. It is much easier to work with than stainless.