Chimney liner length. ?

[TWilk117]

A question of length.
Hello, I have been looking at different chimney liners and different insulation methods.
The chimney liner insulation blankets I have seen only come in lengths of 10’ or 5’.
Does it only need one up top, or do I need to buy two?
The chimney is masonry and close to center in the house. It only rises 18”-24” above peak of roof..
pre insulated chimney liners are a bit pricey. I think it may be over kill.
Thought?
Thanks and Happy New Year!

 

[Corey]

Depends a bit on what the ultimate goal is:

If you need to meet some building code, then the code should specify what length needs to be insulated. If you're looking to reduce creosote or increase draft 'just a little', the the top 5-10 feet may be all you need. If you need more draft, then insulate more flue accordingly. (The caveat here is that it would be pretty senseless to buy insulation and not install it, so you're probably looking at doing 5, 10, 15, 20 feet, etc) If you're looking to maximize heating efficiency, then insulate all the complete flue.

 

[Ctwoodtick]

Insulate whole length.

 

[bholler]

Insulate the whole thing

 

[TWilk117]

Okay. Thank you for replying.

What about the pre insulated liners?
I’m assuming they’re like a double walled liner?

 

[bholler]

Okay. Thank you for replying.

What about the pre insulated liners?
I’m assuming they’re like a double walled liner?

Well no they are a regular liner wrapped in insulation then wrapped in another liner. The functional part of the liner and insulation is no different than one you would insulate yourself.

 

[TWilk117]

Oh okay @bholler, thank you.
I’ll have to do the legitimate math, but seems to me like a liner and 2 insulation kits is about the same amount of money as getting an insulated liner, and more of a head ache.

 

[bholler]

Oh okay @bholler, thank you.
I’ll have to do the legitimate math, but seems to me like a liner and 2 insulation kits is about the same amount of money as getting an insulated liner, and more of a head ache.

Why do you need 2 insulation kits? Most I have seen are 25'

 

[TWilk117]

@bholler Well the only ones I’ve seen on EBay and on Rockford are only 10’ or 5’...
maybe I haven’t done enough searching.

 

[TWilk117]

Side note: I haven’t exactly gotten up there and measured yet but I’m pretty sure it’s only 15’.

 

[TWilk117]

Well no they are a regular liner wrapped in insulation then wrapped in another liner. The functional part of the liner and insulation is no different than one you would insulate yourself.

That does sound a little better to me though.. more rigid and solid..

dare I say more insulation if it’s an insulated liner within another liner?

 

[bholler]

That does sound a little better to me though.. more rigid and solid..

dare I say more insulation if it’s an insulated liner within another liner?

Nope it is the same amount of insulation. It is definitely less flexible which can be good or bad.