Is Liner Installation OK With No Insulation?

[JotulOwner]

A friend of mine just told me he installed a SS flexible liner in his masonry chimney without insulating it (insulation didn't come with his kit). He has an insert he will be installing in his fireplace. I am not familiar with the layout, so this is all I know right now. I didn't say anything yet, but I have read on this site about insulating liners. I searched the archives and it appears like you can install one uninsulated (in certain climates), but insulation is better for maximizing draft and reducing creosote. He already installed it, so, unless there are real issues to be concerned about, I should probably leave well enough alone. BTW, he lives on Long Island, so it doesn't usually get the kind of cold many of you are used to. Opinions are appreciated.

 

[pgmr]

He can insulate after the fact with vermiculite or perlite. Of course he'll need a block of plate at the f.p. damper to keep it from filling up the fireplace.

 

[Hogwildz]

Last I remember, if the original chimney has clay tiles, and they are in good shape, no cracks, separations etc. I can be unlined. I honestly don.t remember if this meets code.
If no clay tile liner, just brick or tiles are broken, cracked, separated, has to be lined to meet code. And will help draft better as it keeps the liner hotter and less heat loss to surrounding masonry.

 

[Metal]

It needs to be installed per the installation instructions (if it is a listed product). Most manufacturers do allow no insulation, but you may have to use special spacers and there has to be 1" clearance from the chimney to combustibles to be listed. Once again, it will be spelled out in the installation instructions.

 

[rdust]

This is a pretty good read that was posted here before. http://www.aer-online.com/aerpage.phtml?page=ar-vent1

 

[Shari]

This is a pretty good read that was posted here before. http://www.aer-online.com/aerpage.phtml?page=ar-vent1

That is an excellent read - suggest everyone take the time to click on the link.

Shari

 

[drdoct]

I've got an indoor chimney that's quite big (double with lots of brick). No insulation on the liner. It works great. Would it work for others? who knows. I would have had to go with 3" to get insulation down my chimney with the bend and small tiles. If it gives me trouble I can always add the vermiculite later if there is a problem. Don't really seeing it changing though.

 

[Hogwildz]

Ive seen alot of chimneys, and have never seen one with a 1" air space between the tile & the masonry. Not saying it is never done, I guess few & far between. Im guessing alot of chimneys are not up to code.
Glad I relined mine. Everything was in good shape, but no 1" clearance between the flue tiles & the block.

 

[ikessky]

It also makes a difference if the chimney is interior or exterior. I have an interior chimney with a clay flue that looked to be in pretty good condition, so I went ahead and installed the liner with no insulation. If your friend wants to insulate it later (or needs to!) just use the pourable insulation.

 

[gangsplatt]

I installed my flex. SS liner without insulation in my exterior chimney last fall prior to the burning season (which was my first full season). Didn't have a draft issue and I just had a chimney sweep come and clean it in August in preparation for the upcoming season and he stated I had an average amount of creosote.

 

[Shari]

There are lots of reasons to insulate and yet some people don't and apparently have no problem.

Most people look at insulating a liner as 'keeping the liner hot so creosote doesn't accumulate'.

We are playing with fire folks... I think of insulation as keeping fire away from the interior of my home'.

Shari

 

[rdust]

There are lots of reasons to insulate and yet some people don't and apparently have no problem.

Most people look at insulating a liner as 'keeping the liner hot so creosote doesn't accumulate'.

We are playing with fire folks... I think of insulation as keeping fire away from the interior of my home'.

Shari

I agree but I can see both sides of it. It's hard to change peoples thinking when you can look back on history though. Chimney's used to only be brick without clay liners then brick with clay liners and now brick with clay liners(maybe with some cracks) with a stainless steel liner down it. AND then you tell people they have to also insulate the stainless liner.

Kinda hard to believe everyone who burned in a plain old brick chimney in the past didn't burn their house down.

 

[jtp10181]

Its not about draft, its about safty. No sense in explainig it for the 100th time. Read the article posted above.

 

[rowerwet]

unless I am mistaken isn't air the best insulator? if you are worried about keeping the heat in the liner away from the wood in the house, an air gap seems like the best bet, anything you put into the space around the liner would help the transfer of heat to the house frame.

 

[jtp10181]

A sealed air chamber makes for good insulation. This would only be achieved by a double wall pipe with a sealed air chamber. With a breathing air chamber, this would only act to "cool" and not to "insulate".

Insulation does not help heat transfer, its is thermally resistant.

Do I really need to look up all the R values and explain how insulation works...?

 

[Valhalla]

Safety first, function second.

A cold exterior, uninsulated masonry chimney will cause the flue gases in the SS liner to sharply drop in temperature, before exiting at the top. An interior masonry chimney is not quite as cold, but there is still a temp loss. The proper insulation does have functional benefits in all cases.

Please follow the required codes for a framed chase or masonry chimney, interior or exterior. Read and follow them for your spec components and structure. When in doubt, ask a qualified professional.

No short cuts. Safety first, as it is in the family home.

 

[southland]

Mine is insulated and I wouldn't have it any other way. Better to be safe. I did the liner install myself and the cost to insulate was not very much.

 

[theheatelement]

combustibles are things like wood or other substances that may catch fire... Your brick and clay tile are not combustibles.

Ive seen alot of chimneys, and have never seen one with a 1" air space between the tile & the masonry. Not saying it is never done, I guess few & far between. Im guessing alot of chimneys are not up to code.
Glad I relined mine. Everything was in good shape, but no 1" clearance between the flue tiles & the block.

 

[raven]

safety and function do go hand in hand.over the last 30 yrs god knows how many flues i have installed for oil and gas units. clearance and proper flue temps until they exit the flue is the name of the game. with oil and gas if not sized right moisture will bite ya in the azzz sooner or later. be it a rotten brick chimney or soaking wet drywall or worse. nowwww we be playin with creosote and fire. what a magic combo. who had that song burnin down the house? ..............................sorry when i think of that tune a little blond pops into my head that was all about burnin down the house :-S
anyway ,bottom line keep the flue warm with insulation. in my case a block off plate and 20 bucks worth of perlite a little kaolin wool = a cup or 2 of ash when sweeping. makes for an easy sweep good flue temps until its out of the house and alllllllllll is blond with the world %-P

 

[jtp10181]

combustibles are things like wood or other substances that may catch fire... Your brick and clay tile are not combustibles.

Ive seen alot of chimneys, and have never seen one with a 1" air space between the tile & the masonry. Not saying it is never done, I guess few & far between. Im guessing alot of chimneys are not up to code.
Glad I relined mine. Everything was in good shape, but no 1" clearance between the flue tiles & the block.

What does combustibility have anything to do with this statement? Read NFPA guidelines on building a masonry chimney. You should have a 1" air gap from the clay tiles to the surrounding masonry. If this is not done heat can transfer through easier. In the case of a re-line, every liner I have seen is only approved to be installed in a bad flue with the insulation wrap. Without insulation the entire masonry structure must be built to code and pass an inspection.