Insulated Liner on Interior Chimney?

[DKranger22]

I am going to be ordering my first wood burning insert and scheduling the install later this week. The installer that I am going with has recommended using Olympia Forever Flex 316 SS/TI liner. I asked if he would be insulating the liner, and he claims that for my application (the chimney is not on an exterior wall), that it is not necessary. I quoted two other local, reputable shops, who both said the same thing.

From my readings on this forum, most everyone recommends an insulated liner regardless of interorior / exterior chimney. I don't see or hear of any downsides to going with an insulated liner. I get the feeling that it's more of a "pain" (one extra step) for the installer, and something that they probably don't make much profit on (this is the cheapest part of the install... even if they double the markup, it might not be worth their hassle).

Also, when not insulating the liner, the installer can simply carry up the flex liner in its original packaging... nice and neat... and begin feeding it down the chimney while tearing the plastic packaging away in the same motion. Easy peasy. Not only does the installer have to take the extra time to wrap it in insulation, now it becomes more cumbersome to carry up the ladder (it's not neatly coiled anymore). Not that it's difficult to do in the first place, but if he can get home half an hour quicker on a Saturday... who knows.

Should I demand that my liner be insulated, even if I might not "need" it? What should I expect in additional cost for the insulation? I hate to be that picky, PITA customer, but I am hoping to only do this one time, and I want it done right.

 

[Ablaze Tech]

I am pretty sure in the olympia forever flex installation guidelines it requires you to insulate whenever burning solid fuels(wood or pellet). That is of course if you want to maintain the forever warranty. When in doubt call olympia and ask a tech. The liners drop quite easily with insulation on them. It is a two man job. Insulation might cost you anywhere from 400 to 600 more dollars.

 

[DKranger22]

He is a one-man crew, so perhaps this is the reason for the resistance to insulate. I just don't understand why he wouldn't take the opportunity to "upsell me" if there wasn't a valid reason not to. The insulation is more expensive than I thought, so it would be worth the extra half hour labor to get a 20%+ markup on the materials. I just get the sense it's about trying to save time or cut a corner. Overall, I have been very satisfied with him up until our conversation about insulating the liner.

I'm not really worried about voiding the Forever Flex warranty. I believe they also require you to hire a professional sweep every year, provide documentations of said annual sweep, etc., in order to not void the "forever" warranty. I plan to clean the liner myself, so my warranty would be out the window anyways. However, I am more concerned about 1.) reducing my risk of a potential chimney fire and 2.) getting the best performance / draft possible for my insert. From what I understand, this is the main reason for the insulation.

Thanks for the reply... I will be contacting Olympia to get their take.

 

[Ablaze Tech]

4





Insulation Requirements




For Solid Fuel Applications
- Insulation provided for the Forever Flex TM and Armor FlexTM system will be a single½” 13mm

thick or two ¼” 6.5mm layers of insulating blanket. This insulating system is listed to allow zero clearance from the chimney masonry
exterior to combustibles. The 8 lb density insulating blanket must be wrapped around the entire length of the liner in an
unlined, partially lined, or cracked clay tile liner application.


Alternative EverGuardTM

Insulation Mix

or
TherMix®

Insulating method:
The Forever Flex TM and Armor Flex TM lining system can be insulated using EverGuard TM Insulation Mix or TherMix ® brand insulating material. A1 inch 25mm layer of EverGuard TM Insulation Mix or TherMix® between the liner and 4 inch 10cm nominalmasonry provides a zero clearance listing from the chimney masonry exterior to combustibles. If the clay tile liners are
in good condition and the chimney meets existing codes, no insulation is necessary.
Ok so this is from the foreverflex install manual. I guess if the chimney meets code you don't need to insulate. Most chimneys however do not meet code. If this is an interior chimney you must have 2" of clearance all around the chimney. No combustibles can touch it. So just insulate and you will be very happy. If the installer is good he will be able to drop an insulated liner himself. Depending on roof pitch and chimney height.

 

[rwhite]

I am far from a pro and I installed an insulated liner on an outside wall chimney that is 23" off the ground. It ain't that hard. If there is any indication that there are cracks in the masonry I'd do it. If you want it...I'd insist upon it. If that guy won't I bet there are others that will.

 

[Eaglecraft]

I am going to be ordering my first wood burning insert and scheduling the install later this week. The installer that I am going with has recommended using Olympia Forever Flex 316 SS/TI liner. I asked if he would be insulating the liner, and he claims that for my application (the chimney is not on an exterior wall), that it is not necessary. I quoted two other local, reputable shops, who both said the same thing.

From my readings on this forum, most everyone recommends an insulated liner regardless of interorior / exterior chimney. I don't see or hear of any downsides to going with an insulated liner. I get the feeling that it's more of a "pain" (one extra step) for the installer, and something that they probably don't make much profit on (this is the cheapest part of the install... even if they double the markup, it might not be worth their hassle).

Also, when not insulating the liner, the installer can simply carry up the flex liner in its original packaging... nice and neat... and begin feeding it down the chimney while tearing the plastic packaging away in the same motion. Easy peasy. Not only does the installer have to take the extra time to wrap it in insulation, now it becomes more cumbersome to carry up the ladder (it's not neatly coiled anymore). Not that it's difficult to do in the first place, but if he can get home half an hour quicker on a Saturday... who knows.

Should I demand that my liner be insulated, even if I might not "need" it? What should I expect in additional cost for the insulation? I hate to be that picky, PITA customer, but I am hoping to only do this one time, and I want it done right.

DKranger:

The reluctance to insulate SS liners reminds me of concrete contractors doing residential work. They would convince you that reinforcing steel (rebar) is not necessary anymore. But if you watch commercial concrete work being done, you see the amazing quantity of steel that is placed in these structures.

Why not insulate? Insulating the SS liner eliminates one of the variables concerning wood burning - is the liner warm enough from top to bottom to slow the formation of creosote? Will my liner contain a chimney fire, should I have one? Here is one site (there are many) that sells a 6 inch liner kit, 25 feet for $ 229 plus shipping. This is probably less than 10 percent of the total cost for stove, liner and install.

I, with the help of my better half, insulated my 25 foot SS flex liner, carried it to the top of the roof, and placed it down a 13 inch by 13 inch flue - all by ourselves. I was on the roof, she was guiding from inside the house.

You won't regret having insulated your liner.
See: http://www.chimneylinerdepot.com/st...sulation-Kit-6in.-x-25ft.-.5in-Thickness.html

Insulation? We don't need no stinking insulation!

 

[DKranger22]

DKranger:

The reluctance to insulate SS liners reminds me of concrete contractors doing residential work. They would convince you that reinforcing steel (rebar) is not necessary anymore. But if you watch commercial concrete work being done, you see the amazing quantity of steel that is placed in these structures.

Why not insulate? Insulating the SS liner eliminates one of the variables concerning wood burning - is the liner warm enough from top to bottom to slow the formation of creosote? Will my liner contain a chimney fire, should I have one? Here is one site (there are many) that sells a 6 inch liner kit, 25 feet for $ 229 plus shipping. This is probably less than 10 percent of the total cost for stove, liner and install.

I, with the help of my better half, insulated my 25 foot SS flex liner, carried it to the top of the roof, and placed it down a 13 inch by 13 inch flue - all by ourselves. I was on the roof, she was guiding from inside the house.

You won't regret having insulated your liner.
See: http://www.chimneylinerdepot.com/st...sulation-Kit-6in.-x-25ft.-.5in-Thickness.html

Insulation? We don't need no stinking insulation!

Eagle - Thanks for your response, and for providing the link. I totally agree with your sentiments re: the concrete contractors. That's exactly what this feels like.

I contacted Olympia directly, and they were no help. Here is their reply:

Thank you so much for contacting us and for your interest in our products... Regarding your questions, we as a manufacturer do not have any dealings with homeowners so you would actually need to communicate your concerns with your installer. I understand from your inquiry that you have already done this... if you would like to provide the installer information we will certainly contact them and make them aware of your concerns.

I am very sorry I have not been more helpful but for liability reasons we do not get involved with homeowners at all


I am going to contact my installer and push for an insulated liner. I'm willing to pay for it, so I shouldn't have trouble getting what I want.

 

[mellow]

DIY it, that way you are doing it right and save the money. Sounds like you are on the right track. Spring is coming, perfect time to spend your time getting a few friends over to help, beer is always recommended after you get down from the roof.

 

[pen]

What's the diameter of your existing flue? Are you sure there is room for an insulation blanket around a liner?

If not, the pour down method suggested above is what you'd need to do and maybe the fella isn't familiar with it?

pen

 

[DKranger22]

12" x 12". Plenty of room.

 

[chimneylinerjames]

This seems like a DIY case. If the installer is refusing or at the very least giving you a hard time about wanting the best job possible, do it yourself. You will spend less money and you will know it was done up to your standards.

 

[milner351]

I recently purchased and installed an insulated liner - it's not a bad job at all if you have the proper ladder to get you to the top of your chimney.
We have large rectangular chimney crocks - 13x17 - I installed a 6" insulated kit from Rockford - it's a bit awkward making it around corners and the like - but was a pretty straight forward operation - took two of us less than 3 hours start to finish.

We just moved in - I have to complete the install - I'm trying to figure out how much of the excess I left in the fireplace to trim off before trying to wrestle it into the flue of the summit insert.

 

[jrendfrey]

I didn't insulate my liner no problems yet!

 

[Todd 2]

My insurance co. stated to have an insulated liner for there requirements. He checked for it also when he came out for their inspection. Just a thought for some cases

 

[fire_man]

I'm convinced most installers are slanted to do what's best for them. I tried to get quotes for installing an insulated rigid liner down a 12x12 clay liner. Both told me flex was better than rigid, one told me Rigid would never work. Installers hate rigid because it's harder to work with.

I ended up doing it myself.

 

[EatenByLimestone]

I rented a bucket for when I put in my liner. I didn't feel comfortable with that much shear weight on my chimney so I didn't want to go up it with a ladder. The bucket was around $200 if I remember correctly and carried 30 feet of insulated liner up to the top of the chimney and supported it as I pushed, pulled and twisted to get it down the 24 feet to the bottom.

Matt

 

[JTP11]

I rented a bucket for when I put in my liner. I didn't feel comfortable with that much shear weight on my chimney so I didn't want to go up it with a ladder. The bucket was around $200 if I remember correctly and carried 30 feet of insulated liner up to the top of the chimney and supported it as I pushed, pulled and twisted to get it down the 24 feet to the bottom.

Matt

Now that's working like gentleman!

 

[EatenByLimestone]

I've never heard of anybody else doing it, but it really made the job easy. It took a while to convince myself that the machine would handle the bouncing up and down, but it did it without a hitch.

 

[Ashful]

Do you have any zero-clearance issues? If not, it might pay to just use a liner not requiring insulation, such as DuraVent. Insulation is a safety issue if your chimney has any clearance issues, and a performance issue if your chimney is on an exterior wall. I disagree with rwhite's statement that cracks in the masonry are a reason to insulate your liner. Cracks in your masonry is a reason to hire a mason, before you slide the liner down the flue. Make sure the stack is sound before you line it.

 

[fire_man]

Joful, I think what rwhite is saying is that crack's in the liner cause a chimney to have a clearance issue, so it needs a liner with proper insulation. If you had a crack in your ceramic liner, wouldn't you want a liner that provides for a zero-clearance?

Interesting that Todd 2's insurance company demanded an insulated liner.

 

[jdp1152]

I have an exterior one that is insulated and an interior one that isn't. The interior one has been cleaned twice and other than loose ash, it was spotless. No clue on the exterior one so far. Haven't used it that often trying to conserve wood in the event of power outage.

For the exterior chimney, I had to insist on the insulation wrap. It was the recommendation of both shops I was talking with to only use it if the chimney structure had some air issues. Think it was 200 extra to get the wrap and block off plate installed.

 

[Ashful]

Joful, I think what rwhite is saying is that crack's in the liner cause a chimney to have a clearance issue, so it needs a liner with proper insulation. If you had a crack in your ceramic liner, wouldn't you want a liner that provides for a zero-clearance?

I'm by no means the expert on this, but I have had five chimneys lined (I've always lived in old houses with lots of chimneys) in the last ten years. Two of those chimneys were connected to oil burners, both brick stacks with failed clay tile liners. In one case, the clay tile was blown clean thru on the far side from the thimble, and the other had an issue with a failed mortar joint / mis-aligned clay tile. In both cases, I had three different companies quote the lining job, and all three quoted with no insulation on the liner. A similar case on a third chimney fed by three gas boilers (commercial), where the porridge liner was crumbling down into the clean-out, and an un-insulated liner was recommended by three different installers.

So, I'm all for insulating liners -- and even did so on both of my current wood stove liners, but I suspect failed mortar joints are not the reason to insulate your liner.

 

[lumbering on]

My installer did not recommend insulation, on a 35 foot exterior chimney with some masonry issues.
Now that I want to fix it, I've visited 3 different installers, and not a single one recommended insulating, and none of them would do a block off plate.
Not sure what gives here.

 

[begreen]

I can understand the thinking here. But I am also thinking smoke traveling up a 35ft pipe is bound to cool down, a lot. Have you considered dropping down a size and insulating?

 

[lumbering on]

I think I will end up pouring in some type of insulation. A previous thread had debated solid vs loose pour in. I'm leaning toward the loose type.
OP should just do it right from the beginning and use the wrap?