Liner insulation question

[El Finko]

I'm going with a flex liner and I'm debating insulating wrap vs. poured in vermiculite. I figured the difference in cost to be negligible. Any thoughts?

 

[EatenByLimestone]

I know people are happy with both types of insulation. I used a kaowool blanket wrapped around the liner I put in. It works fine. I also stuffed kaowool around the top 2 feet or so of open space at the top of the chimney. I figure it will give me a little bit extra warm air insulation.

Matt

 

[El Finko]

How runny is the vermiculite when poured in? Anybody know? I see one can spend ~$70 on a balloon to seal the bottom of the chimney when you pour the stff in, and am wondering if that's necessary?

 

[pen]

Check about using vermiculite or perlite (perlite will not absorb water) with your liner company. Most that I have come across will not approve the use of vermiculite and it may void any warrantee (they never tested the stuff basically).

For a poured in insulation, the one that seems to be most widely accepted by manufacturers is thermix.

pen

 

[mellow]

Insulation wrap or rigid insulated is the easiest way to go if you have the room for it in your chimney. Pour in mix is a messy ordeal, most do it as a last resort or if they find the mix cheaper than the wrap.

 

[Ashful]

Poured is the absolute last resort, IMO. It's a one-way street. No going back. If you go that route, you better be damn sure you won't want to change the flue diameter, make a modification or repair, etc.