Please help me make sense of chimney liner & insulation choices!
We are installing a Vermont Castings wood-buring fireplace insert into an existing brick fireplace/chimney. The chimney is in the middle of the home (not exterior) and lined with ceramic tile.
This is a DIY project, and money is tight. But we want to do it right. WE're definitely going to install a SS chimney liner (probably flexible due to cost.) Multiple sources say we don't tecnhically NEED to insulate this liner... then again lots of people say we should.
1) Is it OK to buy simply the cheapest flexible SS liner at one of the various chimney-liner places on line? Look like about $275 for a 6", 15-foot kit we'd need...
2) Insulation: it sure looks like using a pour-in insulation like Thermix is a WHOLE lot cheaper, and possibly also easier, than the blanket-wrap stuff. By my rough calcs we'd need only 1 bag of Thermix at $75 versus a blanket-wrap kit at $275. WE're already planning to make a bottom close-off plate for the flue. Is there some reason why the Thermix is not a good idea? I know that we might have trouble getting the blanket-wrapped pipe through the very top of the chimney (which is smaller than the rest of it) so it seems easier to pour something in. Are there other insulation possibilities we haven't looked at yet?
Thanks for any advice!