Will a pre-insulated 6 inch liner fit in 9x9 flue, and a few other things?

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KennyK

Feeling the Heat
Oct 26, 2011
351
Boston
Hi all,

I'm back here at this great forum after many years, still trying to make the dream happen (more on that later). The short version of this post are the following two questions:

1) Will a pre-insulated (half-inch insulation) 6 inch liner fit (with relative ease) down a 9 inch x 9 inch flue in a 35 foot, basically straight, unlined, 100 year old brick chimney? (Recently had it inspected and was told this was what I have and that it should work, but want some second opinions here).

2) Should I get a 304, 316, 316ti or 316 liner - or something else? What else should I know about a liner to go into my existing unlined, brick chimney. I'm connecting to a Jotul F100 nordic wood stove.

Feel free to stop reading with the above questions, but here's the longer version of this post if you're interested! Five years ago I was on this forum a bunch and got a lot of great advice, but due to a somewhat challenging install (and limited finances), I never got it done. I'm back and this time want to get this stove (which has been sitting on my mantel for five years) installed! I have a very high chimney, and am going to hire someone to install the liner. I can make a block off plate and heat shields myself, but not ready to drop the liner on my own at that height. Doing things up to code and getting an inspection is both important to me for my family's safety (first and foremost) and what I have to do for my insurance company not to drop me! I recently got a good price (at least for this area and in comparison to many other outrageous prices) for installing the liner ($750 if I bought the liner from the company that would install it plus their uninsulated 304 liner for $600). However, that company didn't seem to want to use an insulated liner (claiming I didn't need it), just wanted to come the install day without even looking at my chimney first, and has been a bit flakey about responding to me in regards to setting up a time and getting me the documents I need to pull the permit (though they said they would get me these documents). I then called another installer who seemed very thorough and said I should definitely put in an insulated liner (citing code and functionality) and he wouldn't give me a price until coming to check out my house. He came, said I had a 9x9 flue and that I should be able to get a 6 inch pre-insulated liner in it, however, due to the height of the job, my need to pull a permit, his insurance costs, etc., the job would be very expensive - he gave me a crazy price apologetically and told me I could probably find someone else to do it cheaper. In the meantime, the first company finally called me back, and I said that I wanted to do the insulated liner (which they said was $1200 for the full kit). I said I would get back to them in a few days. Now, my head is spinning, but I'm ready to go to the first company pay the $750 plus $1200 for the liner, but before insisting on pre-insulated liner, I want to make sure that it will make it through 9x9 flue that the chimney guy who inspected said I had. I'd have to pay for the liner in advance, so I don't want to shell out the $1200 plus tax only to find it doesn't work. Incidentally, while I could downsize to a 5.5 liner, I'm not sure it makes much of a size difference, and one thing my insurance company asks is that I only use 6 inch liner. Man, is this a challenge! Thanks a million in advance for any advice! By the way, I'm in Boston, if anyone has recommendations for this particular area.
 

mark cline

Minister of Fire
Dec 20, 2012
704
Cattaraugus, NY
Any pictures of the chimney from the outside to determine access . Can a boom lift get into the area to be able to access the chimney safely? Renting a boom lift , drop down a rope to pull up the liner would be ideal , If you have a straight run , proper access . etc. I only have ideas , no way for specifics , not seeing your setup.
 
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bholler

Chimney sweep
Staff member
Jan 14, 2014
25,502
central pa
Ok number 1 yes it will fit

Number 2 any of them are fine 304 is all that is needed for wood and is generally cheaper.
 

KennyK

Feeling the Heat
Oct 26, 2011
351
Boston
Ok number 1 yes it will fit

Number 2 any of them are fine 304 is all that is needed for wood and is generally cheaper.

Thanks bholler! For number 2, is there any reason I would consider something other than a 304 liner? Perhaps to enable me to change fuel type in the future? I don't foresee ever going to coal, but would a different liner enable me (or another future homeowner) to use a pellet stove or gas, or would those all require a new liner regardless? Any other reason to go with anything other than the 304?
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
25,502
central pa
Thanks bholler! For number 2, is there any reason I would consider something other than a 304 liner? Perhaps to enable me to change fuel type in the future? I don't foresee ever going to coal, but would a different liner enable me (or another future homeowner) to use a pellet stove or gas, or would those all require a new liner regardless? Any other reason to go with anything other than the 304?
Pellet would be fine on 304 but gas would need 316. A pellet stove probably wouldt work at 30" though you would probably direct vent it
 

KennyK

Feeling the Heat
Oct 26, 2011
351
Boston
Pellet would be fine on 304 but gas would need 316. A pellet stove probably wouldt work at 30" though you would probably direct vent it

Thanks. If I were to put in the 316, 6" insulated liner, and decided one day to switch to gas, could I then just use that same liner? If I do go with 316, is just plain 316 fine or should it be 316ti, 316l...?
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
25,502
central pa
Thanks. If I were to put in the 316, 6" insulated liner, and decided one day to switch to gas, could I then just use that same liner? If I do go with 316, is just plain 316 fine or should it be 316ti, 316l...?
That would depend on the gas appliance. And any 316 is either ti or l but either will work fine
 

Easy Livin’ 3000

Minister of Fire
Dec 23, 2015
2,920
SEPA
Hey Kenny- Congrats on firing up the dream again after 5 years. You are suffering from analysis paralysis, my friend. Bite down hard and just focus on what you are trying to accomplish today, let go of all the future "what ifs". I speak from experience.

My strong desire to get it done on a deadline, and spend the least amount of money eventually won over. The free liner that came with the stove helped, and the incredible flakiness and/or expense of the installers that came out to give estimates helped, too.

You'll let too much of your life pass by worrying that "maybe" you'll switch to gas or pellets sometime in the future. If you know you will, just get the 316 and get on with it.

We'll be here for moral support and to help push you along when you need it. But, start, decide, and do it. Good luck.
 

KennyK

Feeling the Heat
Oct 26, 2011
351
Boston
Hey Kenny- Congrats on firing up the dream again after 5 years. You are suffering from analysis paralysis, my friend. Bite down hard and just focus on what you are trying to accomplish today, let go of all the future "what ifs". I speak from experience.

My strong desire to get it done on a deadline, and spend the least amount of money eventually won over. The free liner that came with the stove helped, and the incredible flakiness and/or expense of the installers that came out to give estimates helped, too.

You'll let too much of your life pass by worrying that "maybe" you'll switch to gas or pellets sometime in the future. If you know you will, just get the 316 and get on with it.

We'll be here for moral support and to help push you along when you need it. But, start, decide, and do it. Good luck.

ED 3000, how right you are! Serious analysis paralysis on my end and the flakeiness of the installers is really beyond belief! I won't even go into the stories, but just when I think I've got things set, I can't get a call back or confirmation! I guess these guys have more work than they know what to do with. I know a lot of people on this site are advocates for the DYI install, but my problem is I really don't feel comfortable that high up as I my chimney is 35 feet and comes of a very steep slant. Block off plate, heat shield, etc. I can handle. In any case, the most recent is I have installers saying I really don't need the insulated liner. I've read so many mixed things on this site, and have heard mixed things about code. At this point, I'm happy to end the analysis paralysis and go one way or another, but if the good folks here can indulge one more question it is should I do the insulated or not. My chimney is inside the house, but on an exterior wall. The flue is 9x9 (as mentioned). Sleeping well at night knowing the family is safe is number one priority, and getting a good draft is also important! Thanks for any input!
 
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Easy Livin’ 3000

Minister of Fire
Dec 23, 2015
2,920
SEPA
ED 3000, how right you are! Serious analysis paralysis on my end and the flakeiness of the installers is really beyond belief! I won't even go into the stories, but just when I think I've got things set, I can't get a call back or confirmation! I guess these guys have more work than they know what to do with. I know a lot of people on this site are advocates for the DYI install, but my problem is I really don't feel comfortable that high up as I my chimney is 35 feet and comes of a very steep slant. Block off plate, heat shield, etc. I can handle. In any case, the most recent is I have installers saying I really don't need the insulated liner. I've read so many mixed things on this site, and have heard mixed things about code. At this point, I'm happy to end the analysis paralysis and go one way or another, but if the good folks here can indulge one more question it is should I do the insulated or not. My chimney is inside the house, but on an exterior wall. The flue is 9x9 (as mentioned). Sleeping well at night knowing the family is safe is number one priority, and getting a good draft is also important! Thanks for any input!

Yes, insulate it!

I ran into exactly the same thing with the installers. I know code required it in mine. At least one installer backtracked when it wasn't in the original estimate and I asked about it. He lost me on that one.

Get the insulation, it'll be better even if it is not required by code, but I bet that it is.

This is a simple one. I think it cost about $200 extra for 25' of insulation, and it was a snap to install, if you have a level surface to work on.

One last thing, I was the same way about being on the roof, not for the faint of heart. So, I rented a boom lift that eliminated that.
 

Squisher

Minister of Fire
Nov 1, 2015
1,623
vernon BC, Canada
If the chimney is on a outside wall and the backside of it is exposed to the outdoors then it is a exterior masonry chimney requiring 1" of clearance to combustibles. If it is contained entirely within the envelope of the home(except for the roof penetration obviously) then it is an interior masonry chimney and requires 2" clearance to combustibles. The clay or pumice liners must be continuous and not damaged and have mortar in place to seal between the joints. Besides this the entire construction of the chimney needs to be to code in order for these clearances to be relevant.

If none or even one of these things can't be confirmed then defaulting to requiring insulation is the obvious thing to do. For safety.

An insulated liner upgrades a masonry chimney to zero clearance to combustibles.

If your chimney is in great shape, constructed properly, and clearances can be verified no you don't need insulation.

But regardless of all this a insulated liner will offer better performance and a cleaner chimney.

Don't let a chimney company tell you you don't need insulation if it's something they don't even do. What I mean is if they are telling you you don't need insulation ask them why? And then ask them for a price with and without insulation. If they don't install insulated liners ever at all? Run don't walk away.