Installer brings regular liner+insulation for the "insulated liner" request. Is it normal?

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
  • Hope everyone has a wonderful and warm Thanksgiving!
  • Super Cedar firestarters 30% discount Use code Hearth2024 Click here

yuryk

New Member
Feb 17, 2024
98
Eastern MA
Dear Community.

That day has come and finally the installer brought the insert (Lopi Large Flush) with all the installation stuff today. He will install it another day, so I have some time to double-check.

Basically, having a 12x12 flue, what I have requested was that I need an insulated liner and a blockoff plate as many of you guys kindly suggested here. They said that it's very heavy to lift to the chimney, but they might use a machinery for that, so it's okay. Although today the installer brought a regular liner with a box of insulation and metal mesh, saying that this is what the "insulated liner" meant, i.e. it came like that, i.e. it's the package and it's "to-be-insulated-on-site":
[Hearth.com] Installer brings regular liner+insulation for the "insulated liner" request. Is it normal?


Could you please let me know if this option is much worse than a pre-insulated one? I have paid for an "insulated liner kit" ($1400 for insulated vs $900 for regular), but was under impression that I'm getting a pre-insulated one (like this one). When I showed that pre-insulated liner picture to him, he said: "No, this is double-walled one - a totally different beast. You've got an insulated one here for sure."

Funny thing is that with that liner came an installation manual, that says "factory insulated":
[Hearth.com] Installer brings regular liner+insulation for the "insulated liner" request. Is it normal?


Also, looks like there are 35 feet of the insulation, but liner length is about 38 feet, plus this oval adapter, which is also not insulated:
[Hearth.com] Installer brings regular liner+insulation for the "insulated liner" request. Is it normal?


As for the blockoff plate, the guy told me he will use this:
[Hearth.com] Installer brings regular liner+insulation for the "insulated liner" request. Is it normal?


What I saw here on the forum is a bit different, hence a second question - would it be as good?

So, I'm not sure what to do now. I am not a conflictual person, but I don't want to pay such crazy money for something that is not as good as what I have asked and paid for. Therefore, asking for your expertise here - am I losing something by going with this setup? Should I call the shop and demand a pre-insulated liner?

Please understand that I'm completely new to this and this stuff is very expensive for me. So I want to be 100% sure I'm doing the right thing to not regret later. I might be overthinking this, might feel wrong, but it's better to ask and ensure, than not to ask and regret. Thank you in advance!
 
Last edited:
Duraliner is pre-insulated. It does not get an exterior insulation blanket. It's not really needed for a 12" x 12" clay liner. A regular, externally wrapped 6" stainless liner should have lots of wiggle room in there and would be a lot less expensive. The rest is just confusing.
 
Thank you @begreen , very helpful as usual.

Would 1/4" insulation blanked be enough as external wrapping? Or I would need 1/2'?

Does oval adapter need to be insulated as well? It looks like the installer doesn't plan insulating it - I'm not sure if it's okay.

Also, when you say "a lot less expensive" - do you mean for the installation itself, or for the parts? I have checked the parts and regular liner + insulation kit costs approximately the same as a pre-insulated liner... I'm not arguing, just trying to understand.

As for the blockoff plate - what I meant is that a damper sealing kit from above will be used, as opposed to something home-made like this (taken from this forum):
[Hearth.com] Installer brings regular liner+insulation for the "insulated liner" request. Is it normal?

Would it be okay in my case?

Thank you.
 
Other than the fact that they really need to be using 1/2" insulation, it looks like your installer is going to do what you requested,..but keep an eye on them! You got great advice from the forum, and you should be getting what you asked/paid for!
Oh, and that 1/4" insulation doesn't meet code either...
 
  • Like
Reactions: yuryk and bholler
I almost never use pre insulated stuff I just don't see that the increased cost is worth it. We always insulate on-site
 
  • Like
Reactions: yuryk
I almost never use pre insulated stuff I just don't see that the increased cost is worth it. We always insulate on-site
Yes, it makes sense when used instead of busting out the tiles but not in a 12" x 12" flue.
 
Yes, it makes sense when used instead of busting out the tiles but not in a 12" x 12" flue.
We break out lots of clay it's really not a big deal
 
We break out lots of clay it's really not a big deal
It isn't if one is equipped for it and has experience. A lot of smaller installers and most homeowners are not.
 
  • Like
Reactions: bholler
It isn't if one is equipped for it and has experience. A lot of smaller installers and most homeowners are not.
Homeowner no. But any installer should be.
 
Homeowner no. But any installer should be.
A lot of installers are under contract with dealers and tend to go for the low bid, quick installs. We've read about many that balk about having to do a bust out. Not all are as full-service or knowledgeable as your company. I even wonder if some are licensed and insured.
 
  • Like
Reactions: bholler
Thank you everyone! Looks like everything looks good except of the 1/4 thickness of the insulation, which might not meet the code. Would you be so kind to please share the code for me to research if it's enough in my case? I have searched, but found only irrelevant information... The installation is scheduled for tomorrow, I want to make sure I am prepared. Thank you!
 
Thank you everyone! Looks like everything looks good except of the 1/4 thickness of the insulation, which might not meet the code. Would you be so kind to please share the code for me to research if it's enough in my case? I have searched, but found only irrelevant information... The installation is scheduled for tomorrow, I want to make sure I am prepared. Thank you!
Code requires specific clearances to combustibles from the outside of the masonry structure. If you don't have that your liner needs to be insulated to give you zero clearance. That insulation is stated in the installation instructions for that liner and I don't know of any that only require 1/4"
 
  • Like
Reactions: yuryk
That insulation is stated in the installation instructions for that liner
Thank you @bholler . Here is the sticker from the liner:
[Hearth.com] Installer brings regular liner+insulation for the "insulated liner" request. Is it normal?


I've found this product here, but did not find its installation instructions besides what's written on that sticker. It does not mention insulation at all, but says it's to be installed in 0 clearance with combustibles. Does it mean 1/4" insulation is not against the code then?
 
Thank you @bholler . Here is the sticker from the liner:
View attachment 327582

I've found this product here, but did not find its installation instructions besides what's written on that sticker. It does not mention insulation at all, but says it's to be installed in 0 clearance with combustibles. Does it mean 1/4" insulation is not against the code then?
Unless you have the required clearances to combustibles you need 1/2" insulation for that light wall liner to be zero clearance
 
you need 1/2" insulation for that light wall liner to be zero clearance
Interesting... Thank you again @bholler. If you or someone else would be able to provide a reference to a document that has this rule - I would very much appreciate it! It would be VERY helpful! Otherwise I'm afraid, not being as professional as you guys in this domain, I will be looking just as a "smart ass" if I only use words tomorrow...
 
Interesting... Thank you again @bholler. If you or someone else would be able to provide a reference to a document that has this rule - I would very much appreciate it! It would be VERY helpful! Otherwise I'm afraid, not being as professional as you guys in this domain, I will be looking just as a "smart ass" if I only use words tomorrow...
Ask him if the liner meets its ul-1777 listing requirements for zero clearance application without 1/2" insulation. If he says yes ask him for his copy of the installation instructions to confirm that. I am betting they won't have them.
 
  • Like
Reactions: yuryk
In a 12 x 12 flue, why wouldn't one use 1/2" insulation?
 
Sounds like the installer is just cheaping out...trying to maximize profit, or just trying to use up some old inventory laying around...think I'd find a better use for it than a 12x12 flue for sure!
 
Found the confirmation in 2018 International Residential Code (IRC):
[Hearth.com] Installer brings regular liner+insulation for the "insulated liner" request. Is it normal?

And then found the installation instructions for that liner, which has the following info:
[Hearth.com] Installer brings regular liner+insulation for the "insulated liner" request. Is it normal?

[Hearth.com] Installer brings regular liner+insulation for the "insulated liner" request. Is it normal?
Looks like my masonry chimney does NOT meet the NFPA 211 standard (since it's right next to the house walls), so it does not make that exception and I guess I do require 1/2" according to manufacturer instructions.

Thanks again for all your help! I will let you guys know how it goes tomorrow!
 
Found the confirmation in 2018 International Residential Code (IRC):
View attachment 327583

And then found the installation instructions for that liner, which has the following info:
View attachment 327584

View attachment 327585
Looks like my masonry chimney does NOT meet the NFPA 211 standard (since it's right next to the house walls), so it does not make that exception and I guess I do require 1/2" according to manufacturer instructions.

Thanks again for all your help! I will let you guys know how it goes tomorrow!
Nice job finding it sorry I have been busy as hell and didn't have the time to find it for you
 
  • Like
Reactions: yuryk
Sounds like the installer is just cheaping out...trying to maximize profit, or just trying to use up some old inventory laying around...think I'd find a better use for it than a 12x12 flue for sure!
Code is code. The 1/2" is only $70 more than the 1/4".
 
  • Like
Reactions: yuryk
So, looks like in my situation zero clearance does not apply, because the liner will be inside of my existing masonry chimney, which already can accept fireplace fire, so liner insulation does not seem to be needed by the code. But my argument was that since we're insulating it anyway, we should go by the manufacturer instructions, which mentions 1/2" insulation. We were about to order 1/2" insulation, but then they asked if I still with to use a pre-insulated liner to make it easier for them. I found a 6" pre-insulated liner for $500 more with free freight shipping from Woodland Direct and we decided to use that instead to avoid the pain of insulating. I know it's more money for me, but I thought that it would make it easier to install and less prone for snags/tears, so eliminating some risks there. I was on the fence, but Woodland Direct have a $100 rebate, which helped with the taxes, so I went for it! I then found a cheaper version at fireplace-chimneystore (1350 vs 1850 at Woodland), but wasn't sure about quality and reputation of the store, so sticking with former for now.

I have one more question though. The installer offers 2 ways for sealing the bottom: metal block off place vs so called ThermaFiber insulation of the damper area. ThermaFiber appears to have better insulation properties, but I just wanted to check with you guys, what do you recommend from your experience? Thank you.
 
  • Wow
Reactions: stoveliker
I found a 6" pre-insulated liner for $500 more with free freight shipping from Woodland Direct and we decided to use that instead to avoid the pain of insulating.
I'll install your liner insulation for $500, any time, its not hard, at all!
I thought that it would make it easier to install and less prone for snags/tears, so eliminating some risks there.
Putting a 6" insulated liner in a 12x12" flue couldn't be any easier...I put a 8" insulated liner in a 12x12" and there was plenty of room.

That said, a preinsulated liner is fine too, just cost a bit more.
metal block off place
Yup.
 
  • Like
Reactions: yuryk