Pulled the trigger on a new stove-- time to replace the flexliner? (photos)

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CharlieTuna

New Member
Jan 10, 2021
52
PA
Insulation doesn't add that much cost to a liner...$300 maybe, even if a little more, that is pretty cheap insurance to know your good to go on the clearance to combustibles (CTC) around the chimney...plus the chimney will perform better on a modern stove, especially a cat stove like you are looking at...they can have very low flue temps at times...tend to work poorly on a clay flue many times. Insulated liners stay cleaner, and for longer too.
It would be foolish to install a new liner without insulation in my opinion...UNLESS, it was a flue of the appropriate size (most are over sized for modern appliances), internal to the house, AND able to verify the CTC for the full height of the chimney...which is almost impossible to do without tearing into the walls on many/most houses...

Ah, this is for a cat system? We had one and I always disliked it compared to what it replaced. When it died. I made sure not to get another one. The cat system requires more maintenance. Dealers love them for the service contracts they can sell. They don't actually burn off the creosote, and therefore require that heat be wasted up the chimney to keep the creosote from precipitating in the chimney. Thanks for explaining that to everyone. When the cat gets fouled it smokes and the neighbors can complain about it. More reason not to get one. Hopefully, it's not too late for the OP to change his mind.
 

CharlieTuna

New Member
Jan 10, 2021
52
PA
Where are you getting your information? Please provide links showing my claims are incorrect. I have spent countless hours in training from industry pros and code officials regarding the codes applicable to the chimney industry.
You do realize that the info you linked to is just about training about codes not adoption of those codes. You really need to do more research if you want to debate this topic.

That came from your link below:

Here is the applicable code. Read r1003.18

Which one of your posts was wrong?

It appears you conflated two different code issues. One is that the modern code requires greater clearances to combustibles than previously. The other is that a masonry chimney must have a liner, but it can be clay, or something else. Some older houses may not be in compliance with the spacing IF the masonry isn't thick enough, but the masonry chimneys were also thicker of yore.


And yes clay liners are perfectly acceptable if built to code with the required clearances. Unfortunately very few are.

It sure sounds like your corporate training is to scare people and only offer one solution.
 

Sailrmike

Feeling the Heat
Sep 20, 2017
295
06371
Ah, this is for a cat system? We had one and I always disliked it compared to what it replaced. When it died. I made sure not to get another one. The cat system requires more maintenance. Dealers love them for the service contracts they can sell. They don't actually burn off the creosote, and therefore require that heat be wasted up the chimney to keep the creosote from precipitating in the chimney. Thanks for explaining that to everyone. When the cat gets fouled it smokes and the neighbors can complain about it. More reason not to get one. Hopefully, it's not too late for the OP to change his mind.
I'd like to give you a suggestion, please don't take offense. I reccomend that you spend more time reading threads on here before making so many uninformed and opinionated posts.
 

brenndatomu

Minister of Fire
Aug 21, 2013
6,792
NE Ohio

bholler

Chimney sweep
Staff member
Jan 14, 2014
27,054
central pa
That came from your link below:



Which one of your posts was wrong?

It appears you conflated two different code issues. One is that the modern code requires greater clearances to combustibles than previously. The other is that a masonry chimney must have a liner, but it can be clay, or something else. Some older houses may not be in compliance with the spacing IF the masonry isn't thick enough, but the masonry chimneys were also thicker of yore.




It sure sounds like your corporate training is to scare people and only offer one solution.
Ok what I said was that the op's liner should be insulated and that it was required for code and for safety reasons. Looking at the fireplace I can guarantee it does not have the required clearances. I absolutely never said clay liners cannot meet code or be safe. They absolutely can be. But they rarely are.

In addition modern code does not require higher clearances than previous codes. They have never changed requirements.

Exactly what corporate training have I had???
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
27,054
central pa
Ah, this is for a cat system? We had one and I always disliked it compared to what it replaced. When it died. I made sure not to get another one. The cat system requires more maintenance. Dealers love them for the service contracts they can sell. They don't actually burn off the creosote, and therefore require that heat be wasted up the chimney to keep the creosote from precipitating in the chimney. Thanks for explaining that to everyone. When the cat gets fouled it smokes and the neighbors can complain about it. More reason not to get one. Hopefully, it's not too late for the OP to change his mind.
What cat stove did you have? Did you take the time to learn to use it properly?
 

CharlieTuna

New Member
Jan 10, 2021
52
PA
It would be foolish to install a new liner without insulation in my opinion...UNLESS, it was a flue of the appropriate size (most are over sized for modern appliances), internal to the house, AND able to verify the CTC for the full height of the chimney...which is almost impossible to do without tearing into the walls on many/most houses...

Just to add that another reason to actually check inside the walls, is that, from experience, the expansion of the chimney frequently creates cracks and moisture that attracts pests like termites, especially on an external chimney. Termite damage, with paper thin bits of wood poses a danger of combustion. In an older house it's worth checking in a remodeling project. It's always interesting to what corners the builder cut years ago.

When the top of a chimney is rebuilt, as the OP did, it is also possible to check the clearances without opening the walls.
 

CharlieTuna

New Member
Jan 10, 2021
52
PA
I'd like to give you a suggestion, please don't take offense. I reccomend that you spend more time reading threads on here before making so many uninformed and opinionated posts.

Well we have been heating with a wood stove for over 40 years now. In that time I've formed some opinions. I buy things. I don't get sold by a slick sales pitch. I can tell when someone is trying to sell me more than I need, or a flawed system. No thanks on the cat system. Many others feel the same way. Spending more money to send more heat and pollutants up the chimney doesn't make any sense.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
27,054
central pa
Just to add that another reason to actually check inside the walls, is that, from experience, the expansion of the chimney frequently creates cracks and moisture that attracts pests like termites, especially on an external chimney. Termite damage, with paper thin bits of wood poses a danger of combustion. In an older house it's worth checking in a remodeling project. It's always interesting to what corners the builder cut years ago.

When the top of a chimney is rebuilt, as the OP did, it is also possible to check the clearances without opening the walls.
How do you think a roofline up rebuild allows you to check for clearances on the chimney the whole way? You really seem to have lots of opinions that are not based upon actual facts or experience. I rebuild at least a dozen chimneys either roofline or attic floor up a year and doing that does not give you access to the rest of the chimney for inspection at all. And honestly most people will be much happier with me charging them an extra $300 or $400 for insulation on the liner than tearing their walls open to check for or make proper clearances. Especially when you factor in the performance benefits.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
27,054
central pa
Well we have been heating with a wood stove for over 40 years now. In that time I've formed some opinions. I buy things. I don't get sold by a slick sales pitch. I can tell when someone is trying to sell me more than I need, or a flawed system. No thanks on the cat system. Many others feel the same way. Spending more money to send more heat and pollutants up the chimney doesn't make any sense.

I read back and saw that you owned a vc winter warm insert. That is one of the worst stoves ever manufactured. Basing your opinion of cat stoves on that is not wise at all. Good cat stoves have much lower emissions and lower exhaust temps.
 

Rickb

Minister of Fire
Oct 24, 2012
1,181
St.Louis
This is very very funny to read.... You have a new member posting based on mis-infomation at best against one of the most knowledgeable members I have seen here ever. On top of that Bholler is defending cat stoves which many people seem to think he hates! lol

I understand he doesnt hate them and for him and many others that wont be running there stones turned to low all the time cat stoves are not for everyone, but this thread is lol.........
 
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CharlieTuna

New Member
Jan 10, 2021
52
PA
Ok what I said was that the op's liner should be insulated and that it was required for code and for safety reasons. Looking at the fireplace I can guarantee it does not have the required clearances.

I prefer to actually measure such things. Don't know how you can tell from the fireplace what the clearances are between the chimney and the wood framing, and since we don't know how thick the masonry is in the chimney, we don't know what clearance is required by the code. It does vary if you actually read it.

I absolutely never said clay liners cannot meet code or be safe. They absolutely can be. But they rarely are.

I don't trust builders, so I can agree with you somewhat on that. It should be checked, but if the clay liner is up to spec, there is no need for anything else. A non-insulated stainless steel liner in such a case would exceed the code, not fail to meet it.

In addition modern code does not require higher clearances than previous codes. They have never changed requirements.

Seriously? You are back to claiming omniscience about every single building code from every municipality in the Commonwealth that ever was before it was consolidated at the state level in 2002! Wow! What's funny is that the present code actually is variable if the chimney is considered to be part of a masonry wall. In that case combustibles can abutt the masonry as long as its 12 " from the flue liner. If the masonry is thick enough it acts as its own insulation. So the old colonial buildings had thicker chimneys with the wood beams and rafters abutting them with no safety issues. Of course, you don't like chimneys radiating heat to the house as they did for thousands of years...

Exactly what corporate training have I had???
[/QUOTE]
 

CharlieTuna

New Member
Jan 10, 2021
52
PA
This is very very funny to read.... You have a new member posting based on mis-infomation at best against one of the most knowledgeable members I have seen here ever. On top of that Bholler is defending cat stoves which many people seem to think he hates! lol

I understand he doesnt hate them and for him and many others that wont be running there stones turned to low all the time cat stoves are not for everyone, but this thread is lol.........


I am actually citing from the somewhat hidden PA state wide code that your "knowledgeable" member doesn't seem to have actually read. OK, that's funny.
 

CharlieTuna

New Member
Jan 10, 2021
52
PA
How do you think a roofline up rebuild allows you to check for clearances on the chimney the whole way? You really seem to have lots of opinions that are not based upon actual facts or experience. I rebuild at least a dozen chimneys either roofline or attic floor up a year and doing that does not give you access to the rest of the chimney for inspection at all. And honestly most people will be much happier with me charging them an extra $300 or $400 for insulation on the liner than tearing their walls open to check for or make proper clearances. Especially when you factor in the performance benefits.

When we had the top of our chimney rebuilt it was possible to check. With an unfinished attic, its possible to check the clearances at the roof and floor, and make assumptions going down. From the top, one could probe down or use an inspection camera. You would need to actually want to do it though.

When I do things, for my house, or my loved one, I am thorough. More thorough than a contractor. I want to know if something is wrong. Sending more heat and pollution up the chimney certainly isn't a performance benefit.
 

CharlieTuna

New Member
Jan 10, 2021
52
PA
I read back and saw that you owned a vc winter warm insert. That is one of the worst stoves ever manufactured. Basing your opinion of cat stoves on that is not wise at all. Good cat stoves have much lower emissions and lower exhaust temps.

Really, one was enough. "They can't get any worse", isn't an effective sales pitch. Cat's are technically not the way of progress. I prefer to burn all of the hydrocarbons hot and then work on how to safely get that heat into the house, than pollute by sending them up the chimney and waste that potential energy. No good Boy Scout would do that. So now we learn that we should spend more to waste heat too. Then there's the issue of the added weight, which makes them harder to move, and the loss of space inside, etc. No thanks.
 

Whirled Peas

Member
Mar 7, 2019
35
Vermont
Well this thread sure got going while I was gone.

- I thoroughly understand what I'm getting into in regards to moving from a tube stove to a hybrid stove, maintaining a catalyst, lower flue temps for longer, etc (and am excited about it!).

- My brick fireplace column is pretty beefy, but there are certainly combustibles touching the bricks at both the attic floor and the roof line.

- Given the amount of creosote I clean out of my chimney each season, I have felt like my hearth pad and mantel trim clearances were more of a safety hazard than the flex/masonry/brick chimney set up, but I'm a handy DIY homeowner, not a code-aware chimney sweep which is why I was motivated to post my question to begin with. For me, if insulating this particular liner set up was going to give me performance improvements, then I'll likely pull the old liner out and throw in a new one. It's nothing I can't do in a day and this end of the house is going to undergo some extensive remodeling, so with a new stove also in the cards, the new liner is actually pretty trivial in the scope of the whole picture. I've been renting this house and am in the process of buying it from the owners and so these upgrades are on the ASAP timeline now.

- I'm a member of my town's volunteer fire department and for a town of only 1,900 residents, we sure see an awful lot of chimney fires each winter. I've seen some horrific set ups and some very clogged chimneys and am well aware that a new liner and a sweep is a lot cheaper than the damage that a fire and the fire department will do to my house. I like fire safety.

Thanks for all your inputs.

edit for spelling
 
Last edited:

bholler

Chimney sweep
Staff member
Jan 14, 2014
27,054
central pa
how you can tell from the fireplace what the clearances are between the chimney and the wood framing, and since we don't know how thick the masonry is in the chimney, we don't know what clearance is required by the code. It does vary if you actually read it.
I know from years of experience inspecting thousands of chimneys. Chimneys built like this one do not have proper clearances
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
27,054
central pa
Well this thread sure got going while I was gone.

- I thoroughly understand what I'm getting into in regards to moving from a tube stove to a hybrid stove, maintaining a catalyst, lower flue temps for longer, etc (and am excited about it!).

- My brick fireplace column is pretty beefy, but there are certainly combustibles touching the bricks at both the attic floor and the roof line.

- Given the amount of creosote I clean out of my chimney each season, I have felt like my hearth pad and mantel trim clearances were more of a safety hazard than the flex/masonry/brick chimney set up, but I'm a handy DIY homeowner, not a code-aware chimney sweep which is why I was motivated to post my question to begin with. For me, if insulating this particular liner set up was going to give me performance improvements, then I'll likely pull the old liner out and throw in a new one. It's nothing I can't do in a day and this end of the house is going to undergo some extensive remodeling, so with a new stove also in the cards, the new liner is actually pretty trivial in the scope of the whole picture. I've been renting this house and am in the process of buying it from the owners and so these upgrades are on the ASAP timeline now.

- I'm a member of my town's volunteer fire department and for a town of only 1,900 residents, we sure see an awful lot of chimney fires each winter. I've seen some horrific set ups and some very clogged chimneys and am well aware that a new liner and a sweep is a lot cheaper than the damage that a fire and the fire department will do to my house. I like fire safety.

Thanks for all your inputs.

edit for spelling
I absolutely agree the hearth and mantle issues are much more concerning than liner insulation
 

begreen

Mooderator
Staff member
Nov 18, 2005
91,422
South Puget Sound, WA
How old is the fireplace and chimney system? Some of the old colonial fireplaces actually had exposed wood on the interior of the chimney. It sometimes takes a camera to see this, especially if the wood is blackened with soot or has started to char.

What is the ID of the masonry chimney?
 

Whirled Peas

Member
Mar 7, 2019
35
Vermont
How old is the fireplace and chimney system? Some of the old colonial fireplaces actually had exposed wood on the interior of the chimney. It sometimes takes a camera to see this, especially if the wood is blackened with soot or has started to char.

What is the ID of the masonry chimney?

That sounds moronic!

The fireplace is circa 1815. The clay tiles were installed in the early 80s I believe and I'd have climb up to double check, but I want say it's 8x12 rectangular.
 

Whirled Peas

Member
Mar 7, 2019
35
Vermont
This summer/fall we'll be stripping all of trim and drywall off of that hearth and that end of the house and starting over with a slightly different floor plan. The fireplace will be standing, largely un-cladded on all four sides, as a central column. So... lots of photos to come.
 
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begreen

Mooderator
Staff member
Nov 18, 2005
91,422
South Puget Sound, WA
That sounds moronic!

The fireplace is circa 1815. The clay tiles were installed in the early 80s I believe and I'd have climb up to double check, but I want say it's 8x12 rectangular.
Maybe so, but we have seen it. Ashful's stone house had two, massive chimneys with internal oak beams.

An 8x12 insulated liner would need to be oval. Not a problem, but something to be aware of.
 

Whirled Peas

Member
Mar 7, 2019
35
Vermont
This end of the house was an early addition to a 1790 original structure. THAT hearth has a main, cooking fireplace like this one and two smaller fireplaces in the two bedrooms. The entire ~15'x20' base of that structure is held up by lots of HUGE (~8"x14") timbers that that sit on a perimeter foundation of dry stacked stone that effectively creates this root cellar-type space within the basement, under the timbers. All of that is within the house's main stone foundation.
 
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bholler

Chimney sweep
Staff member
Jan 14, 2014
27,054
central pa
That sounds moronic!

The fireplace is circa 1815. The clay tiles were installed in the early 80s I believe and I'd have climb up to double check, but I want say it's 8x12 rectangular.
It is but not that uncommon.
 

Sailrmike

Feeling the Heat
Sep 20, 2017
295
06371
This end of the house was an early addition to a 1790 original structure. THAT hearth has a main, cooking fireplace like this one and two smaller fireplaces in the two bedrooms. The entire ~15'x20' base of that structure is held up by lots of HUGE (~8"x14") timbers that that sit on a perimeter foundation of dry stacked stone that effectively creates this root cellar-type space within the basement, under the timbers. All of that is within the house's main stone foundation.
I've seen an old chimney down here built with xxl timbers at basement level, masonry above. Was told it was built this way to reduce the overall weight of the structure.