Masonry wall adapter - insulate it or leave as it?

[rtrev37]

Hello, I am installing a new masonry double wall adaptor (for a wood stove) into my new 6 inch chimney liner that is also a double wall or smooth wall liner. As you can see from the pic, there is a 1" or so gap between the new chimney liner and the previous (larger) liner I had before. Once I place my new adaptor, the chimney liner will be suspended with a gap all around it from the adapter till the tee in the back.

Question: Does this gap need to be filled with insulation? should it be filled with insulation or can it be left as it? will insulating it make for a better draft due to the insulation and keeping that horizontal run warmer longer?

Objective: My first objective is safety. Second objective is to have a good draft since I could not insulate the entire liner due to the original clay limiting space availability to insulate the liner with the 1/2 insulation. The original clay was in good condition. My after thought was insulating the liner from the wall adapter inside the home all the way up to the tee.

What is your opinion? thank you for reading and commenting

 

[bholler]

Hello, I am installing a new masonry double wall adaptor (for a wood stove) into my new 6 inch chimney liner that is also a double wall or smooth wall liner. As you can see from the pic, there is a 1" or so gap between the new chimney liner and the previous (larger) liner I had before. Once I place my new adaptor, the chimney liner will be suspended with a gap all around it from the adapter till the tee in the back.

Question: Does this gap need to be filled with insulation? should it be filled with insulation or can it be left as it? will insulating it make for a better draft due to the insulation and keeping that horizontal run warmer longer?

Objective: My first objective is safety. Second objective is to have a good draft since I could not insulate the entire liner due to the original clay limiting space availability to insulate the liner with the 1/2 insulation. The original clay was in good condition. My after thought was insulating the liner from the wall adapter inside the home all the way up to the tee.

What is your opinion? thank you for reading and commenting View attachment 246027 View attachment 246028

Do you have the required 12" of masonry surrounding that old crock? If you do then there will be no need safety wise. If you dont have that you need to do an insulated wall thimble. If you dont know you need to find out.

Also that doublewall liner should never be used horizontal like you have it there. It needs to be vertical and right side up to keep creosote out from inbetween the layers. The way you have it there will be creosote trapped that you cant clean.

Did you check for proper clearances from the outsidevof the masonry chimney to combustibles before installing without insulation?

 

[rtrev37]

Do you have the required 12" of masonry surrounding that old crock? If you do then there will be no need safety wise. If you dont have that you need to do an insulated wall thimble. If you dont know you need to find out.

Also that doublewall liner should never be used horizontal like you have it there. It needs to be vertical and right side up to keep creosote out from inbetween the layers. The way you have it there will be creosote trapped that you cant clean.

Did you check for proper clearances from the outsidevof the masonry chimney to combustibles before installing without insulation?

Hello bholler, yes, the red brick wall is full brick from top to bottom with a 6 inch space between the brick and the cinder block. my whole first floor is cinder blocked. The hole that exits the house is lined with an 8" clay liner and then a 7" steel liner inside of that followed by the new 6 inch liner. The exterior chimney is all brick from top to bottom with a clay liner inside followed by the new 6" double wall liner.

Although it is all mansonry, I think I would still want it to be insulated but wanted to make sure if that was an option or not an option.

I am glad you told me about the steel liner inside running horizontally. If it is a smooth wall, how would creosote get stuck in this liner? I never thought of that but even more on how compared to a steel line. Is n't it being a smooth wall make creosote easily removed when I sweep it horizontally? am I missing something on how its constructed?

 

[bholler]

Hello bholler, yes, the red brick wall is full brick from top to bottom with a 6 inch space between the brick and the cinder block. my whole first floor is cinder blocked. The hole that exits the house is lined with an 8" clay liner and then a 7" steel liner inside of that followed by the new 6 inch liner. The exterior chimney is all brick from top to bottom with a clay liner inside followed by the new 6" double wall liner.

Although it is all mansonry, I think I would still want it to be insulated but wanted to make sure if that was an option or not an option.

I am glad you told me about the steel liner inside running horizontally. If it is a smooth wall, how would creosote get stuck in this liner? I never thought of that but even more on how compared to a steel line. Is n't it being a smooth wall make creosote easily removed when I sweep it horizontally? am I missing something on how its constructed?

So no combustibles at all in that 6" space? If that is the case i would switch out that horizontal section of liner for rigid pipe. Then just stuff ceramic wool in at the face to stop air movement.

As far as the chimney itself goes does it have a 1" air gap between the outside of the masonry and any combustible material other than corner trim? If not the liner needs to be insulated.

That smooth wall liner is only attached on one side. The other side is completly loose which means creosote can get under that edge and be trapped. Did you install the vertical liner right side up?

 

[rtrev37]

So no combustibles at all in that 6" space? If that is the case i would switch out that horizontal section of liner for rigid pipe. Then just stuff ceramic wool in at the face to stop air movement.

As far as the chimney itself goes does it have a 1" air gap between the outside of the masonry and any combustible material other than corner trim? If not the liner needs to be insulated.

That smooth wall liner is only attached on one side. The other side is completly loose which means creosote can get under that edge and be trapped. Did you install the vertical liner right side up?

I had a chimney company install the liner but funny how they would place the same chimney liner as the horizontal run oppose to a rigid steel pipe and not tell me what you are saying. I figured it being double wall would have been better then a single wall rigid pipe.

As to placing it in the correct direction, I can not verify but did wonder if there was a way I can varify since I learned about the "correct direction" after from watching a youtube video.

 

[bholler]

I had a chimney company install the liner but funny how they would place the same chimney liner as the horizontal run oppose to a rigid steel pipe and not tell me what you are saying. I figured it being double wall would have been better then a single wall rigid pipe.

As to placing it in the correct direction, I can not verify but did wonder if there was a way I can varify since I learned about the "correct direction" after from watching a youtube video.

Did that chimney company do a full inspection to confirm you have required clearances before installing the liner un insulated?

To check for the proper direction go to the top and see if you can slide a knife between the flaps of that liner from the top. If you can it is upside down. Also you need to be extremely carefull when cleaning that type of liner. They are very easily damaged.

The way they terminated that liner at the wall is also very unprofessional. That alone makes me skeptical of the quality of their work.

 

[rtrev37]

So no combustibles at all in that 6" space? If that is the case i would switch out that horizontal section of liner for rigid pipe. Then just stuff ceramic wool in at the face to stop air movement.

As far as the chimney itself goes does it have a 1" air gap between the outside of the masonry and any combustible material other than corner trim? If not the liner needs to be insulated.

That smooth wall liner is only attached on one side. The other side is completly loose which means creosote can get under that edge and be trapped. Did you install the vertical liner right side up?

after stuffing the ceramic wool, would you seal the edges with high temp cement to enclose it? or would the ceramic wool along be enough? I thought of ceramic wool but then read that using the same insulation from the chimney liner would be better...but I could not find it online other then the large expensive role...

the installer had mention that wrapping the chimney liner before installing is good but it will rip apart on its way down due to the limited space...it was really tight according to him.

 

[bholler]

after stuffing the ceramic wool, would you seal the edges with high temp cement to enclose it? or would the ceramic wool along be enough? I thought of ceramic wool but then read that using the same insulation from the chimney liner would be better...but I could not find it online other then the large expensive role...

The chimney insulation is ceramic wool.

And yes i typically do mortar over the insulation but if it is covered by a trim plate i dont really think it is nessecary

 

[rtrev37]

Did that chimney company do a full inspection to confirm you have required clearances before installing the liner un insulated?

To check for the proper direction go to the top and see if you can slide a knife between the flaps of that liner from the top. If you can it is upside down. Also you need to be extremely carefull when cleaning that type of liner. They are very easily damaged.

The way they terminated that liner at the wall is also very unprofessional. That alone makes me skeptical of the quality of their work.

unfortunately, the chimney is too high up for me to climb or reach. I do all my cleaning and visual inspection from bottom up. I will be using a rigid plastic 6" brush with my flexible rods from bottom up.

if it was placed incorrectly, will if affect the draft? as to inspection, the individual did look, checked and told me all is good. He told me about the previous liner after removing it while I was there and about the new liner. He did say I had more then enough clearance on the chimney and on the wall that runs horizontally due to it having no combustible and also mentioned no requiring insulation on that horizontal run. But I was still wondering on increasing the draft and keeping it warmer simply because it is a horizontal run and not the perfect set up of a straight up and down chimney line.

Regardless, I will call them again and have the liner removed and replaced with a rigid steel liner and fill it with a ceramic blanket in hopes it will improve my draft and/or create less creosote by keeping it warmer.

 

[bholler]

unfortunately, the chimney is too high up for me to climb or reach. I do all my cleaning and visual inspection from bottom up. I will be using a rigid plastic 6" brush with my flexible rods from bottom up.

if it was placed incorrectly, will if affect the draft? as to inspection, the individual did look, checked and told me all is good. He told me about the previous liner after removing it while I was there and about the new liner. He did say I had more then enough clearance on the chimney and on the wall that runs horizontally due to it having no combustible and also mentioned no requiring insulation on that horizontal run. But I was still wondering on increasing the draft and keeping it warmer simply because it is a horizontal run and not the perfect set up of a straight up and down chimney line

No if it is upside down it will not effect draft. But it will direct any liquid including creosote in between the layers where it can never be cleaned. In some cases it can even seep through the crimped seam letting creosote escape and be trapped outside the stainless liner. Insulating that short horizontal section will make no difference considering the chimney is exterior with an uninsulated liner.

How did he look? Are you able to see that 6" gap and make sure there is no combustible material there?

How did he confirm you have that 1" air gap? Is it visible outside or did he go in the attic and drill test holes to check?

 

[rtrev37]

No if it is upside down it will not effect draft. But it will direct any liquid including creosote in between the layers where it can never be cleaned. In some cases it can even seep through the crimped seam letting creosote escape and be trapped outside the stainless liner. Insulating that short horizontal section will make no difference considering the chimney is exterior with an uninsulated liner.

How did he look? Are you able to see that 6" gap and make sure there is no combustible material there?

How did he confirm you have that 1" air gap? Is it visible outside or did he go in the attic and drill test holes to check?

you can visually see the 6" gap and with a flash light look from top to bottom between the brick and the cinderblock from under the stairwell . I can see the clay liner as well with nothing around it or combustible material. Outside you can see the gap between the chimney wall and the house. it was covered with a metal sheet or trimming..

under that stairwell I have my hot water heater and fully wrapped but that is more than 20 inches of clearance

 

[bholler]

you can visually see the 6" gap and with a flash light look from top to bottom between the brick and the cinderblock from under the stairwell . I can see the clay liner as well with nothing around it or combustible material. Outside you can see the gap between the chimney wall and the house. it was covered with a metal sheet or trimming..

under that stairwell I have my hot water heater and fully wrapped but that is more than 20 inches of clearance

Ok good I am sorry for pushing that issue but if it is wrong things can go very wrong. It seems as long as the liner is right side up you have a safe install. It won't perform as well as it should because of the lack of insulation but it should work.

 

[bholler]

The lack of insulation on those masonry walls is going to eat up allot of BTUs as well.

 

[rtrev37]

Ok good I am sorry for pushing that issue but if it is wrong things can go very wrong. It seems as long as the liner is right side up you have a safe install. It won't perform as well as it should because of the lack of insulation but it should work.

I was just reading what you were talking about on here: https://www.mtlfab.com/media/Flexible_Stainless_Steel_Chimney_Liner_Instructions-L2589.pdf

I also saw the rigid steel pipe section although there was a part before that, that seem you can attached the appliance to the flex liner directly as well. I have seen that done as well bit was not sure if that was correct or not but they did it that way.

I am always grateful for your input....tell me your back ground on these installs? or profession

 

[bholler]

I was just reading what you were talking about on here: https://www.mtlfab.com/media/Flexible_Stainless_Steel_Chimney_Liner_Instructions-L2589.pdf

I also saw the rigid steel pipe section although there was a part before that, that seem you can attached the appliance to the flex liner directly as well. I have seen that done as well bit was not sure if that was correct or not but they did it that way.

I am always grateful for your input....tell me your back ground on these installs? or profession

Yes you can just sweep a liner out if there is enough room but it doesnt sound like you have that room. But that really is not good for solid fuel appliances. You want that tee bottom to allow space for dirt that falls to buildup without restricting flow. You also cant bend that double wall stuff very tight without the inner wall buckling.

And yes i do this professionally i install 50 plus liners most years.

 

[rtrev37]

Yes you can just sweep a liner out if there is enough room but it doesnt sound like you have that room. But that really is not good for solid fuel appliances. You want that tee bottom to allow space for dirt that falls to buildup without restricting flow. You also cant bend that double wall stuff very tight without the inner wall buckling.

And yes i do this professionally i install 50 plus liners most years.

hum I wished to have spoken to you sooner. what type of chimney liner would you recommend using? I installed the lifetime double wall smooth liner..

 

[rtrev37]

hum I wished to have spoken to you sooner. what type of chimney liner would you recommend using? I installed the lifetime double wall smooth liner..

in addition, what would you have recommended in doing when the space is too tight to add the insulated liner? I heard filling it with the cement mix insulation is ok but a disaster when changing the liner in the future due to the difficulty of removing it...

 

[rtrev37]

Yes you can just sweep a liner out if there is enough room but it doesnt sound like you have that room. But that really is not good for solid fuel appliances. You want that tee bottom to allow space for dirt that falls to buildup without restricting flow. You also cant bend that double wall stuff very tight without the inner wall buckling.

And yes i do this professionally i install 50 plus liners most years.

What type of brush will work well for this type of liner to clean?. I had a corrugated single wall liner before this new one. However, when it was changed, I realized that the installer had 7" towards the bottom of the line which match the tee but 6" in the middle and one portion was 5 1/2 " which is the area I had to always push a little harder to get by brush thru when cleaning. the whole liner was pieced together with different sizes which I was not aware off and the snake who installed it never told me.....that was over 15 yrs ago

 

[bholler]

hum I wished to have spoken to you sooner. what type of chimney liner would you recommend using? I installed the lifetime double wall smooth liner..

Mid weight or heavy wall flex liner. It is still smooth wall but the metal is at least twice as thick. And there is no part that is not attached. But even regular corregated lightwall is much more durable than what you have.

 

[bholler]

What type of brush will work well for this type of liner to clean?. I had a corrugated single wall liner before this new one. However, when it was changed, I realized that the installer had 7" towards the bottom of the line which match the tee but 6" in the middle and one portion was 5 1/2 " which is the area I had to always push a little harder to get by brush thru when cleaning. the whole liner was pieced together with different sizes which I was not aware off and the snake who installed it never told me.....that was over 15 yrs ago

You need a soft bristle brush. Or a rotary cleaner with soft smooth whips.

 

[rtrev37]

You need a soft bristle brush. Or a rotary cleaner with soft smooth whips.

now I am wondering it this type of chimney will withstand a 2100 F temperature..?? what brand makes the heavy weight wall flex liner? I thought I was getting the good stuff but guess not...

 

[bholler]

now I am wondering it this type of chimney will withstand a 2100 F temperature..?? what brand makes the heavy weight wall flex liner? I thought I was getting the good stuff but guess not...

Yes it is tested to 2100 f. Most good manufacturers make a heavy wall or mid weight liner. We use Olympia products but there are many others

 

[rtrev37]

Yes it is tested to 2100 f. Most good manufacturers make a heavy wall or mid weight liner. We use Olympia products but there are many others

so if the Lifetime liner that I have can withstand the 2100 F then that is good. However, the one you mentioned seem to last much longer? want to know in which way it is better other then the obvious which you already shared on the inner liner buckling... I guess I will need to find a soft bristle brush too because the one I have and thought of using is rigid and hard although still a plastic bristle...I will need a softer one...maybe that is why he had mentioned to be careful in cleaning it....I was not aware why he mentioned it although I did wonder for a second on why I need to be careful on cleaning a steel liner. One: he had mentioned in pulling down when cleaning, you end up pulling the liner down over time. and two: I don't recall but it had something to do with being careful but don't exactly remember... but since we are talking about it, it does make more sense. Then he ended with his method of sweeping is always from bottom up and never top down. personally, I just though he wanted to make the money for cleaning it oppose to do it myself...but I was not sure...although what he mentioned also made sense but I know I can not climb and do this myself..once a year is ok but I like cleaning at least 2-3 times during the burning season; a little after my starting season, mid way and after the last burn.

 

[bholler]

so if the Lifetime liner that I have can withstand the 2100 F then that is good. However, the one you mentioned seem to last much longer? want to know in which way it is better other then the obvious which you already shared on the inner liner buckling... I guess I will need to find a soft bristle brush too because the one I have and thought of using is rigid and hard although still a plastic bristle...I will need a softer one...maybe that is why he had mentioned to be careful in cleaning it....I was not aware why he mentioned it although I did wonder for a second on why I need to be careful on cleaning a steel liner. One: he had mentioned in pulling down when cleaning, you end up pulling the liner down over time. and two: I don't recall but it had something to do with being careful but don't exactly remember... but since we are talking about it, it does make more sense. Then he ended with his method of sweeping is always from bottom up and never top down. personally, I just though he wanted to make the money for cleaning it oppose to do it myself...but I was not sure...although what he mentioned also made sense but I know I can not climb and do this myself..once a year is ok but I like cleaning at least 2-3 times during the burning season; a little after my starting season, mid way and after the last burn.

I would not clean that liner 2 to 3 times a year. That inner wall will be torn up in a few years at that. They are not durable because that inner wall is only .005 or .006 thick and is only attached on one edge. That edge is extremely easy to snag with a brush and distort or tear it.

 

[rtrev37]

I would not clean that liner 2 to 3 times a year. That inner wall will be torn up in a few years at that. They are not durable because that inner wall is only .005 or .006 thick and is only attached on one edge. That edge is extremely easy to snag with a brush and distort or tear it.

such bad news...I must give this company a bad rating for not informing me of this before changing it nor giving a better option to consider...now to think that the one I had may have been a much better quality since I always cleaned it and was still looking good inside in over 15 yrs....with exception to the varied sizes it had inside......however, it did feel much stronger. but now I will have to keep a look out and inspect it more frequently over time while taking pics to see how it compares over time....but I will know after the first burning season ends while getting use to my new stove...