Pre-insulated Liners? Fireflex?

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DStydo

New Member
Sep 27, 2017
20
Reidsville NC
I see that firesidechimneysupply sells pre-insulated liners for a reasonable price. I have also checked out Olympia but they seem to be a bit more $$

https://www.firesidechimneysupply.c...-insulated-stainless-steel-chimney-liner.html

Appears to be standard lightweight SS inner liner, insulation and then alum outer liner. 6"x20' is a little over 400 to your door. I'm looking at the all the standard .006" flex liners+ insulation kits and they are the same price if not more expensive. Why aren't more people using something like this? Tried searching but didn't come up with much.

thanks,
Drew
 
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I installed one of these back in Nov 2014. First liner I've installed so I've got nothing to compare it to - I liked the fact that I didn't have to manually wrap the insulation. No complaints so far, I have a Woodstock Progress Hybrid connected to it.
 
I put a Magnaflex (now National Chimney IIRC) pre-insulated liner in a few years back too...pretty happy with it...I would do it again. I have installed regular "insulate it yourself" liners too...this is way easier! FYI, I paid about the same price as your quote.
Not sure why more people don't use them...I think they are slightly less flexible than a standard liner maybe...also I think many companys charge quite a bit more for them...
 
I put a Magnaflex (now National Chimney IIRC) pre-insulated liner in a few years back too...pretty happy with it...I would do it again. I have installed regular "insulate it yourself" liners too...this is way easier! FYI, I paid about the same price as your quote.
Not sure why more people don't use them...I think they are slightly less flexible than a standard liner maybe...also I think many companys charge quite a bit more for them...
We use heavy wall for almost all woodstove installs and no one offers preinsulated heavy wall. We have used preinsulated for a few furnaces. And it is fine but we are so used to wrapping insulation it is not a big deal.

We also only use olympia products because they are fast and reliable when it comes to delivery. With good consistent quality.
 
I'm sure wrapping and installing a regular liner would be much easier if you did it everyday...and had help that knew what to do...but for the average DIY job, pre-insulated is niiiice!
 
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Bholler - I have been checking out various threads and it appears that folks (such as yourself) recommend to stay away from double wall .013" flex with the smooth inner since it can kink and result in snags if flexed too much.

So the heavy single wall flex is more desirable? Have you seen failures with light single wall flex? Do you install light flex or is heavy flex your standard? Would really appreciate hearing your 2 cents on this.

Assuming no liner abuse, what lifespan can someone expect out of the light flex and heavy flex?

thanks guys!

Drew
 
Bholler - I have been checking out various threads and it appears that folks (such as yourself) recommend to stay away from double wall .013" flex with the smooth inner since it can kink and result in snags if flexed too much.

So the heavy single wall flex is more desirable? Have you seen failures with light single wall flex? Do you install light flex or is heavy flex your standard? Would really appreciate hearing your 2 cents on this.

Assuming no liner abuse, what lifespan can someone expect out of the light flex and heavy flex?

thanks guys!

Drew
I have seen failures in all types of liners. The 2ply stuff is the worst. From my experience you will be lucky to get 10 years out of one for a woodstove. And i have seen some bad after only a few years. Regular light wall you should see about 20 years. And that is typically what the lifetime warranties are good for on them. Heavy wall should easily get you 30 years. We have started replacing some of the origonal heavywall liners my father put in about 30 years ago. But most of them were on old fishers or alaskas that put allot more heat up the chimney than a modern stove. So with a modern stove run correctly i would expect more than that.

And yes rigid can fail also. Usually it is the fasteners that fail on them but i have seen the tee and the bottom section or 2 rail on them.

We do see allot of failures from coal here as well but i dont factor that in when discussing liners for wood. Coal will eat anything.
 
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Wow, great information. Based on your experience, why do the double wall liners "fail"? I understand them getting kinked and whatnot but do they burn through or something?

Thoughts on the fireflex which is essentially the double wall separated by insulation? Think it will fail in similar manner?

thanks,

Drew
 
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Wow, great information. Based on your experience, why do the double wall liners "fail"? I understand them getting kinked and whatnot but do they burn through or something?

Thoughts on the fireflex which is essentially the double wall separated by insulation? Think it will fail in similar manner?

thanks,

Drew
That kink will cause turbulence which creates a hot spot and can make it fail.

It looks like the regular fireflex is just plain old light wall liner that you can get preinsulated. The stuff that if treated right should get you atleast 20 yrs. But they also have fireflex smooth wall which is the stuff i would stay away from.

They also have fireflex heavy wall
 
bholler (and anyone else),

I'm about to make my flue purchase and decided to go with the Champion/Olympia heavy flex...

Where is the best place to buy the liner? My local installer doesn't sell Olympia/Champion and of course I'm trying to get the best deal possible.
 
bholler (and anyone else),

I'm about to make my flue purchase and decided to go with the Champion/Olympia heavy flex...

Where is the best place to buy the liner? My local installer doesn't sell Olympia/Champion and of course I'm trying to get the best deal possible.
We buy from olympia
 
When I installed the furnace in my avatar I put a 2 ply liner in...big $...it had raised lips inside right from the get go...live and learn, I wouldn't do it again! :mad:
 
Insulating a liner is very important and sometimes required, but unless you have a "13 x 13" clay flue or are going to knock out the clay tiles, you probably do not have the room for a pre-insulated or blanket insulation on you liner. 1/2" adds anywhere to 1" - 1.5" to a flex liner that is already 6 1/4" OD to begin with. Removing the clay tiles and installing an insulated liner is a common practice.
 
My flue is slightly larger than 10x12. Want to say 10.25x12.25. I figure I'm looking at stuffing an 8" OD liner (including insulation) down the chimney.. Its pretty straight shot down the chimney with not a lot of mortar protrusion or misalignment.

I figured there was reasonable clearance. Am I dreaming?

thanks,

Drew
 
brennsatou - I "think" that fireflex isn't what you're thinking regarding two ply liners. It isn't a smooth inner layer prone to kinking and whatnot. Its basically an easy flex liner, insulation and instead of wrapping with tape, mesh, etc. They put another alum liner over. What brand liner did you use?

thanks,

Drew
 
brennsatou - I "think" that fireflex isn't what you're thinking regarding two ply liners. It isn't a smooth inner layer prone to kinking and whatnot. Its basically an easy flex liner, insulation and instead of wrapping with tape, mesh, etc. They put another alum liner over. What brand liner did you use?

thanks,

Drew
Yeah I am familiar...I put a "2 ply" in for my furnace...then put a pre-insulated liner in for the stove. The 2 ply was CLD, umm, don't remember the model right now, gonna hafta look it up. The P-I liner was Magnaflex brand Insulflex IIRC...they were bought out by National Chimney I believe...
EDIT, it was CLD Flex King Pro...
 
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If you go with the heavy flex it is also smooth wall but not prone to linking etc. this is what I'm going to do. I believe. Just have to figure out how to get from the chimney to the class A on the roof. My chimney was basically eliminated and roofed over by the previous owner