Chimney Liner Validation

[ColdNorCal]

Installing insert into existing chimney. House is ~45 years old. I have lived in it for 20 years. When I moved in their was a very used looking pellet stove. I have no idea how many years it was in service. I am providing this information as I inspected the chimney for the first time and was VERY surprised how clean it was. I scraped the sides with a sharp poker and it did not leave any marks.

Although the chimney flue and sides look good, their is about 1"-1 1/2" of ash on the smoke shelf. Some of it is also cement slurry and pieces. Presumably from construction since the flu looks to be in very good condition.

Given the flu ID is 10"x15" and internal, I plan on using a 6" stainless steel liner without insulation. The total flu height from wood stove base to top vent will be about ~14'.

If their is a more economical approach then a stainless liner, please recommend one. I understand some may "slamb" the stove in. Running a new liner for safety is worth it to me. Although insulating it seems unnecessary.

Also, I want to install a "T" for a clean-out. To make space for one, a damper cross brace would need to be removed. The damper is 48" wide and has two cross braces and another cross brace for the damper lever. Is it ok to remove one, maybe even two braces? But leaving the damper frame installed.

Comments and suggestions are appreciated.

 

[begreen]

Insulate the liner. A 14' run is on the short side. Insulating will make it safer and draft better. There's plenty of room so there's really no reason not to insulate. This is infrastructure so invest a little now for better performance and safety for the future. The chimney and smoke shelf needs to be completely cleaned before installing the liner. I don't see a problem removing the damper.

PS: unless you know the clearances of the chimney from any combustibles are satisfactory, code requires insulating the liner. I've seen a couple cases where this really made a difference. One was in my house and another was in a close friend's dad's house. You are protecting against pyrolysis in the chimney surrounding house structure which can take years to manifest, but when it does it can be bad.

 

[blacktail]

Installing a T sounds pointless. Accessing it would be a huge pain. Without it, your liner junk will fall into your insert where it will disappear with your next fire.

 

[begreen]

Installing a T sounds pointless. Accessing it would be a huge pain. Without it, your liner junk will fall into your insert where it will disappear with your next fire.

Yes, I've never seen one on an insert and that short liner will need help maintaining draft. A tee would not help at all.

What insert is going in here?

 

[ColdNorCal]

Insulate the liner. A 14' run is on the short side. Insulating will make it safer and draft better. There's plenty of room so there's really no reason not to insulate. This is infrastructure so invest a little now for better performance and safety for the future. The chimney and smoke shelf needs to be completely cleaned before installing the liner. I don't see a problem removing the damper.

PS: unless you know the clearances of the chimney from any combustibles are satisfactory, code requires insulating the liner. I've seen a couple cases where this really made a difference. One was in my house and another was in a close friend's dad's house. You are protecting against pyrolysis in the chimney surrounding house structure which can take years to manifest, but when it does it can be bad.

I did call the county bldg dept asking about code and chimney liners for wood inserts. They usually respond within 48 hours.

Internal chimneys do have some advantage to offset a non-insulated the liner. I will insulate the bottom at the damper and seal the top chimney plate. This should provide a good environment to heat up the interior of the chimney flu. And most of the chimney flu is either enveloped by the house interior or by the attic space. Only a couple feet of chimney bricks are exposed to outside temps.

Per the installation manual:

4. Installation of an interior chimney is always preferable to an exterior chimney. Indeed, the interior chimney will, by definition,
be hotter than an exterior chimney, being heated up by the ambient air in the house. Therefore, the gas which circulates will
cool more slowly, thus reducing the build-up of creosote and the risk of chimney fires.

5. The draft caused by the tendency for hot air to rise will be increased with an interior chimney.

Installing a T sounds pointless. Accessing it would be a huge pain. Without it, your liner junk will fall into your insert where it will disappear with your next fire.

Since the hearth is 48" wide, this would leave about 10 inches to reach on the side of the insert to access the T. The T bottom cap would only be about 12"-16" from the front of the fireplace. The T would be on the side of the stove, not in the rear.

The clean-out T is only something I read about others doing. They says its worth installing one. I have no idea. If it is possible with easy access, would you install one or is it not worth the time? Again, this is my first rodeo

Yes, I've never seen one on an insert and that short liner will need help maintaining draft. A tee would not help at all.

What insert is going in here?

Ok, so a T is not a good idea for a wood stove with 14' of chimney.

Either a CW2900/Escape 1800i or a Breckwell SW470i. The Breckwell is discounted nicely at a shop that will no longer be in the stove business. I like certain things about each of them. Not in love with any of them....


United States Stove Company Breckwell SW740 2.5 11000-36700

Stove Builder International, Inc. Osburn 1800-I 2.7 9700-36300

Stove Builder International, Inc. CW2900 Insert Escape 1800i 3.9 11600-32200

 

[blacktail]

If you installed a T it would be above your insert. It would also be pointless. Having the crud from your liner fall out of a T above your insert, or behind it, would not be better than having the crud just fall INTO your insert.

 

[begreen]

While at it also look at the Englander 13-NCi.
(broken link removed to https://amfm-energy.myshopify.com/collections/wood-stoves-new-timber-ridge-heat-cook-camp-stoves/products/50tnc13i-epa-certified-noncatalytic-wood-stove-1550131500-new)

 

[bholler]

I did call the county bldg dept asking about code and chimney liners for wood inserts. They usually respond within 48 hours.

Internal chimneys do have some advantage to offset a non-insulated the liner. I will insulate the bottom at the damper and seal the top chimney plate. This should provide a good environment to heat up the interior of the chimney flu. And most of the chimney flu is either enveloped by the house interior or by the attic space. Only a couple feet of chimney bricks are exposed to outside temps.

Per the installation manual:

4. Installation of an interior chimney is always preferable to an exterior chimney. Indeed, the interior chimney will, by definition,
be hotter than an exterior chimney, being heated up by the ambient air in the house. Therefore, the gas which circulates will
cool more slowly, thus reducing the build-up of creosote and the risk of chimney fires.

5. The draft caused by the tendency for hot air to rise will be increased with an interior chimney.




Since the hearth is 48" wide, this would leave about 10 inches to reach on the side of the insert to access the T. The T bottom cap would only be about 12"-16" from the front of the fireplace. The T would be on the side of the stove, not in the rear.

The clean-out T is only something I read about others doing. They says its worth installing one. I have no idea. If it is possible with easy access, would you install one or is it not worth the time? Again, this is my first rodeo




Ok, so a T is not a good idea for a wood stove with 14' of chimney.

Either a CW2900/Escape 1800i or a Breckwell SW470i. The Breckwell is discounted nicely at a shop that will no longer be in the stove business. I like certain things about each of them. Not in love with any of them....


United States Stove Company Breckwell SW740 2.5 11000-36700

Stove Builder International, Inc. Osburn 1800-I 2.7 9700-36300

Stove Builder International, Inc. CW2900 Insert Escape 1800i 3.9 11600-32200

Do you have the required clearances to combustibles from the outside of the masonry structure to combustible any combustible material? In you case that would be 2". If you dont have that which most dont you are required by code manufacturers instructions and ul listings to insulate the liner for safety reasons.

 

[Bootstrap]

I would insulate it. I didn't insulate mine and though it drafts excellent I will likely pull it out and insulate it sometime in the spring or summer.
The 1800i is an excellent unit, I highly recommend it.

 

[ColdNorCal]

While at it also look at the Englander 13-NCi.
(broken link removed to https://amfm-energy.myshopify.com/collections/wood-stoves-new-timber-ridge-heat-cook-camp-stoves/products/50tnc13i-epa-certified-noncatalytic-wood-stove-1550131500-new)

Thank you.

Do you have the required clearances to combustibles from the outside of the masonry structure to combustible any combustible material? In you case that would be 2". If you dont have that which most dont you are required by code manufacturers instructions and ul listings to insulate the liner for safety reasons.

Yes, I need to verify in the attic space. The terra cotta flu liner ID is 10 1/2" x 15". Centering the 6" liner would provide a 2" and 4 1/2" space within the existing flu. Does this have any influence on the code?

I would insulate it. I didn't insulate mine and though it drafts excellent I will likely pull it out and insulate it sometime in the spring or summer.
The 1800i is an excellent unit, I highly recommend it.

To be honest, cost is a major concern. If the county says its necessary, then it will be installed per code. Otherwise, I could take your approach and try it without a liner first.

 

[bholler]

Thank you.

Yes, I need to verify in the attic space. The terra cotta flu liner ID is 10 1/2" x 15". Centering the 6" liner would provide a 2" and 4 1/2" space within the existing flu. Does this have any influence on the code?

To be honest, cost is a major concern. If the county says its necessary, then it will be installed per code. Otherwise, I could take your approach and try it without a liner first.

No theoretical interior clearances dont matter at all when it comes to code. Code calls for 2" of clearance on the outside period. Without that you need insulation. No way around it at all. And you will like the performance gains anyway.

And no matter what the county says dont run it without a liner. We are talking about a fire inside your house here. You dont want to cut corners.

 

[ColdNorCal]

No theoretical interior clearances dont matter at all when it comes to code. Code calls for 2" of clearance on the outside period. Without that you need insulation. No way around it at all. And you will like the performance gains anyway.

And no matter what the county says dont run it without a liner. We are talking about a fire inside your house here. You dont want to cut corners.

Understood and already aware of any potential issues. Given the chimney condition and overall environment mentioned previously, a liner would not provide any better sleep at night. None the less, a visit into the attic space is required.

Also, I live on 5 1/2 acres with lots of oak and hard wood fruit trees. Free fuel Any possible small gains a liner may provide is unimportant "for me".

Again, if its absolutely necessary, it will be installed.

 

[bholler]

Understood and already aware of any potential issues. Given the chimney condition and overall environment mentioned previously, a liner would not provide any better sleep at night. None the less, a visit into the attic space is required.

Also, I live on 5 1/2 acres with lots of oak and hard wood fruit trees. Free fuel Any possible small gains a liner may provide is unimportant "for me".

Again, if its absolutely necessary, it will be installed.

What potential issues are you aware of? Because if you truly were aware of the issues you would not even consider running without a liner.

 

[begreen]

Hoping NorCal meant insulation and not considering installation without a liner. Any of the stoves mentioned would be illegal to install without a liner and they would burn terribly, especially trying to draft into a large chimney tile in a milder climate zone.

 

[bholler]

Hoping NorCal meant insulation and not considering installation without a liner. Any of the stoves mentioned would be illegal to install without a liner and they would burn terribly, especially trying to draft into a large chimney tile in a milder climate zone.

I dont think so from his previous posts. I think he is seriously considering running it as a slammer.

 

[begreen]

Good advice has been given. Hopefully the OP will read up a bit on people complaining about poor performance of their stoves when it is actually just a case of weak draft due to a too short chimney. For me in this case insulating the liner is a no-brainer. The money saved by not trying to rig up a tee assembly will help pay for the insulation. In mild temps a 14' liner is going to need some help.

 

[ColdNorCal]

Was considering a liner only, no insulation. Never considered a slammer install.

I say "was considering" because I did some recon in the crawl space and PT lumber is touching the chimney in the attic space.

The bldg dept has not called me back so no confirmation on code requirements. Given the consistent comments and years of experience on this forum, insulating the liner is a "no brainer" Although the extra $200 is making me flinch...

On a side note, living in this county has allowed me to upgrade things on the house and follow code per when the house was originially constructed. In other words, did not have to abide to any new bldg codes. I have no idea if installing an insert would also fall into that category.

 

[bholler]

Was considering a liner only, no insulation. Never considered a slammer install.

I say "was considering" because I did some recon in the crawl space and PT lumber is touching the chimney in the attic space.

The bldg dept has not called me back so no confirmation on code requirements. Given the consistent comments and years of experience on this forum, insulating the liner is a "no brainer" Although the extra $200 is making me flinch...

On a side note, living in this county has allowed me to upgrade things on the house and follow code per when the house was originially constructed. In other words, did not have to abide to any new bldg codes. I have no idea if installing an insert would also fall into that category.

Ok i misunderstood you i am sorry. I can tell you what california code is concerning this issue. It is the same as the rest of the country and the same as what i said earlier. Your county cannot over ride state code. They can only not enforce it. But the codes are there for a reason. And in this case it is there to help prevent structure fires.

 

[Berl2169]

So for what it’s worth......I can’t compete with the knowledge of the folks already replied on this thread...but I’ll share my two cents anyway. I tried the “slammer” approach and point blank don’t work and my flue was smaller than yours but doesn’t sound like you considered that anyway. My chimney is interior and about 21’ from insert to top and did not install insulated liner. Don’t install the “T” that’s a waste of money (since you have budget restrictions)...instead buy yourself the soot eater and clean the liner yourself and learn what intervals you need to do this in. Practice on the sooner rather than later approach and burn dry wood and I don’t think you would have problems. You could always save and buy an insulated liner in the mean time.


Sent from my iPhone using Tapatalk

 

[AlbergSteve]

Somebody's gonna have a smokey house...

 

[RobbieB]

I have a 14 foot flue in the central valley of CA. I did both, with and without insulation. 6 inch flex SS liner all the way. One year bare and the next year insulated with the pour down mix.

Both worked, but the draft is better with the insulation and the flue temps are better too as evidenced by my pale yellow heat discolored SS cap that didn't happen w/o insulation.

 

[AlbergSteve]

Good advice has been given. Hopefully the OP will read up a bit on people complaining about poor performance of their stoves when it is actually just a case of weak draft due to a too short chimney. For me in this case insulating the liner is a no-brainer. The money saved by not trying to rig up a tee assembly will help pay for the insulation. In mild temps a 14' liner is going to need some help.

Can you imagine how much help it might need just running it in to a 10x15 masonry stack...

 

[begreen]

Can you imagine how much help it might need just running it in to a 10x15 masonry stack...

It would be almost like running it with no flue, but fortunately (and wisely) that's not the plan.

 

[ColdNorCal]

Somebody's gonna have a smokey house...

This seems to draft without a flu. lol

Look at 2:00 minute mark:

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[begreen]

This seems to draft without a flu. lol
Look at 2:00 minute mark:

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LOL, it burns... with the door open. That is one cold stove, it will never get hot enough to bake the paint without some stack on it.