Flex Liner Advice

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Aug 20, 2014
128
Eden, NY
hi everyone, so I have a stainless steel flex liner running up an existing masonry chimney (the previous home owner did this, not me). I was checking it out today and I noticed that the liner has some dents in It (see attached picture). Is this anything to be worried about? I'm assuming it occurred when he put the liner down the chimney or possibly from a chimney sweep?

also, you can notice the guy didn't insulate the liner. Should I pull out the liner and wrap it in an insulation blanket?

any advice is appreciated! Thanks!

Zach
 

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Looks a lot like my install.......I feel my chimney is so well built that it could hold a nuclear reactor in check........but not knowing anything about the construction of your chimney the right thing to do would be to insulate it, although it doesn't look like you have the room for insulation below the damper. Small dents I wouldn't worry about.
 
Looks a lot like my install.......I feel my chimney is so well built that it could hold a nuclear reactor in check........but not knowing anything about the construction of your chimney the right thing to do would be to insulate it, although it doesn't look like you have the room for insulation below the damper. Small dents I wouldn't worry about.

Thanks for your reply! It is a little tight at the damper - I might just try to shove some blanket insulation up there towards the damper and towards the top of the liner. I would hate to pull it and do more damage to the liner.
 
Thanks for your reply! It is a little tight at the damper - I might just try to shove some blanket insulation up there towards the damper and towards the top of the liner. I would hate to pull it and do more damage to the liner.
Do you have the required clearance from the outside of the masonry structure to any combustible materials? It is 1" for an exterior chimney and 2" for an interior one. If you don't you could have a safety issue with no insulation.
 
Do you have the required clearance from the outside of the masonry structure to any combustible materials? It is 1" for an exterior chimney and 2" for an interior one. If you don't you could have a safety issue with no insulation.
I'm somewhat confused on the whole clearance thing - can you explain it to me? Here is a picture of the exterior chimney that the liner runs up through.
[Hearth.com] Flex Liner Advice
 
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http://www.rumford.com/code/clearances.html

Here is a copy of the code. Generally it is a safe bet that you dont have proper clearance I inspect lots of chimneys and I would say less that 1% have the required clearance
 
When I pulled mine I found it easier to pull from the bottom rather than fight it up from the roof. That is a short chimney so you shouldn't have much work in it to pull, wrap, then put back down, make a chimney cone to pull from and make the job easier.

I'm sure the wife will enjoy me pulling it into our living room - haha. Thank you for the suggestion!
 
When I pulled mine I found it easier to pull from the bottom rather than fight it up from the roof. That is a short chimney so you shouldn't have much work in it to pull, wrap, then put back down, make a chimney cone to pull from and make the job easier.
that all depends on the chimney some are easier to pull out the bottom but I find most are easier to pull out the top. Usually once you get out of the damper area it goes pretty easy. unless you have offsets or a rectangle liner.
 
that all depends on the chimney some are easier to pull out the bottom but I find most are easier to pull out the top. Usually once you get out of the damper area it goes pretty easy. unless you have offsets or a rectangle liner.
I'll play with the pull to see what seems best. I know putting it back in with the insulation on is going to be a snug fit but i'm pretty confident it will go back in.
 
I'll play with the pull to see what seems best. I know putting it back in with the insulation on is going to be a snug fit but i'm pretty confident it will go back in.
What size clay liners are in the chimney?
 
What is the smallest clay flue you have fit a 6" wrapped liner down?

8" round stainless chimney but that is actually 8" and there are no offset joints. The oly way I have ever fit a wrapped liner in an 8x12 is by ovalizing. I normally don't try a wrapped liner unless it is a 12x12 or the liners are removed.
 
8" round stainless chimney but that is actually 8" and there are no offset joints. The oly way I have ever fit a wrapped liner in an 8x12 is by ovalizing. I normally don't try a wrapped liner unless it is a 12x12 or the liners are removed.

hmm, ok - so any suggestions if it doesn't fit? I'd rather not use that pour in mix insulation.
 
I'd rather not use that pour in mix insulation.
You would not have enough room for it to bring you up to code anyway.

hmm, ok - so any suggestions if it doesn't fit?
Ovalize or break out tiles. We do both it all depends on the situation. Is you liner actually 8" is the flue straight and are all of your joints aligned well? If so you may have a chance
 
so I wrote about this earlier but I found some more information so I thought I'd create a new thread. the previous home owner ran a SS flex liner up through an existing chimney. It isn't insulated so I decided I would try pulling out the liner and insulating it the proper way. However, I have noticed some issues and need advice...

  1. I found that the liner with insulation is going to be too tight of a fit. I also noticed that the terracotta flue seems to be in decent shape, but the joints between the flue sections seem to be missing mortar..probably not ideal...image below is looking down the flue from top of chimney.
  2. I found the original manual for the flex liner (the brand is MagnaFlex), and it actually states not to put insulation around the liner...so now I'm just confused since I thought this was best practice, especially if the terracotta isn't in great shape.
  3. I also noticed some discoloration and a potential weak spot where the liner makes a slight curve at the damper...see image below..is this concerning?
  4. should I leave the current 6" liner and just do the best i can and stuff insulation down around the top of the liner?
  5. should I pull the liner out and replace it with a 5.5" liner and properly wrap it in insulation? This would allow me to get it down the chimney.
  6. is it possible for a 5.5" liner to attach to a 6" stove connection? The stove manual (Lopi 1250) says it should be connected to a 6" liner but I'm assuming that is stated for warranty purposes.

sorry this was long winded. Any suggestions or advice is greatly appreciated!

thank you!
 

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This needs the context that is in the first thread. Merging for greater clarity.

Discoloration of stainless is normal with heat.
 
With your short chimney I would toss out the 5.5" insulated liner idea.

I would get a quote on busting out the terracotta so you can fit a 6" insulated liner down.

Have you had any experience with the loose pour in insulation? I feel like I read somewhere that it could potential contain harmful elements?
 
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