Non insulated liner?

[JamesH]

We are hoping to install a PE insert in our pre existing exterior masonry chimney.

The flu is 6 by 10” so unfortunately an insulated liner won’t fit.

Does this mean a wood stove is simply not an option? We have talked to 5 or 6 installers in the are who have all said a single walled liner is acceptable. My husband is convinced it’s safe but I’m skeptical…

 

[kborndale]

In most instances the liner is required by code. If you have a chimney fire it's useful in not burning your house down. It's quite common to remove the clay liner in your chimney so that an insulated liner will fit. They also make ovalized liners.

 

[begreen]

We are hoping to install a PE insert in our pre existing exterior masonry chimney.

The flu is 6 by 10” so unfortunately an insulated liner won’t fit.

Does this mean a wood stove is simply not an option? We have talked to 5 or 6 installers in the are who have all said a single walled liner is acceptable. My husband is convinced it’s safe but I’m skeptical…

If 6" x 10" ID, an oval liner will fit insulated. Any good installer should have mentioned this.

 

[JamesH]

In most instances the liner is required by code. If you have a chimney fire it's useful in not burning your house down. It's quite common to remove the clay liner in your chimney so that an insulated liner will fit. They also make ovalized liners.

Thank you for this. According to our town code an insulated liner is not required which is another reason my husband is team single walled liner. He’s not willing to remove the clay liner so it’s looking like we may have to explore some other heating options.

 

[begreen]

An insulated liner is not required IF -
a) this is an interior chimney that has at least 2" clearance from any combustibles all the way up through the roof.
b) this is an exterior chimney that has 1" clearance from any combustibles all the way up.

 

[JamesH]

If 6" x 10" ID, an oval liner will fit insulated. Any good installer should have mentioned this.

I’m calling one more place tomorrow but so far the 6 that I’ve talked to who all have fabulous reviews said not to insulate! And we live in the northeast where these installs are quite common. It’s very surprising, I always try to research as much as possible… so grateful I found this forum and grateful for all of this valuable input.

 

[JamesH]

An insulated liner is not required IF -
a) this is an interior chimney that has at least 2" clearance from any combustibles all the way up through the roof.
b) this is an exterior chimney that has 1" clearance from any combustibles all the way up.

From what I’ve read there’s no way to really determine clearance to combustibles fully unless you start taking down walls? Is that correct?

 

[begreen]

From what I’ve read there’s no way to really determine clearance to combustibles fully unless you start taking down walls? Is that correct?

Yes, that's correct in many cases though easier to determine with an exterior chimney.

 

[JamesH]

Yes, that's correct in many cases though easier to determine with an exterior chimney.

This one is a brick exterior! On the hunt for a great inspector in my area perhaps they can offer more guidance.

 

[Ctwoodtick]

If they’re saying not to insulate-run. They do not know what they’re doing and the good reviews are from people who don’t know any better. Ovalize or break out the clay.

 

[bholler]

I’m calling one more place tomorrow but so far the 6 that I’ve talked to who all have fabulous reviews said not to insulate! And we live in the northeast where these installs are quite common. It’s very surprising, I always try to research as much as possible… so grateful I found this forum and grateful for all of this valuable input.

If a couple in the area are not insulating none of them will. They have to be competitively priced. Its not right but it's how it works.

 

[bholler]

From what I’ve read there’s no way to really determine clearance to combustibles fully unless you start taking down walls? Is that correct?

There is a pretty easy way to. Out of the thousands of chimneys i have inspected only 4 or 5 have the required clearances. It just isn't done

 

[stoveliker]

I see what I think is vinyl siding (a combustible) right against the brick, not with 1" separation.

I don't believe your town code is saying what you say it is as most jurisdictions simply adopt the national fire prevention association code.

 

[JamesH]

I see what I think is vinyl siding (a combustible) right against the brick, not with 1" separation.

I don't believe your town code is saying what you say it is as most jurisdictions simply adopt the national fire prevention association code.

Yes vinyl siding, the building inspector here said we were good to go with a single walled liner but perhaps he just isn’t informed? This whole thing has become very stressful and I trust no local contractor at this point.

I’m going to insist on a liner and tell my husband if he can’t accommodate that we have to explore alternative fuel options.

 

[JamesH]

There is a pretty easy way to. Out of the thousands of chimneys i have inspected only 4 or 5 have the required clearances. It just isn't done

Thank you. My kids safety is of paramount importance to me so I’m going to say liner or no stove. Hopefully we can find a way.

 

[stoveliker]

A single walled liner can be fine. The point is that it needs to be insulated.

 

[retlaw]

I see what I think is vinyl siding (a combustible) right against the brick, not with 1" separation.

I don't believe your town code is saying what you say it is as most jurisdictions simply adopt the national fire prevention association code.

I believe the code says that combustible trim can abut the masonry if more than 8" from flue lining.

 

[JamesH]

A single walled liner can be fine. The point is that it needs to be insulated.

Unfortunately given the size of the flu (6”) anything more than just the stainless liner won’t fit unless we get an oval. Pricing that out today but I read it’s significantly more expensive.

 

[JamesH]

I believe the code says that combustible trim can abut the masonry if more than 8" from flue lining.

Ahhh okay that’s helpful, there’s about 12 inches of brick surrounding the liner.

 

[stoveliker]

I believe that (I thought 8") is for the pass through (thimble), not for the chimney itself?

Outside chimneys need 1" from the outside of the masonry to combustibles.

 

[kborndale]

On top of being required by code and making the installation safer, insulated liners also perform better, you will have better draft and you will produce less creosote (the substance that causes chimney fires) with an insulated liner. On top of all that, my opinion is peace of mind is priceless.

 

[JamesH]

On top of being required by code and making the installation safer, insulated liners also perform better, you will have better draft and you will produce less creosote (the substance that causes chimney fires) with an insulated liner. On top of all that, my opinion is peace of mind is priceless.

I totally agreed, my 2yr old sleeps right next to that chimney I will absolutely not mess around with her safety!

 

[Wisco Shepherd]

You could also explain to your husband that and insulated liner will perform better with much less buildup due to the warmer exhaust gases which could potentially save time and hassle dealing with that. It would definitely be expensive to put in an uninsulated liner and realize that's not going to work for your system and end up having to pull it and replace it with an insulated liner

 

[retlaw]

I believe that (I thought 8") is for the pass through (thimble), not for the chimney itself?

Outside chimneys need 1" from the outside of the masonry to combustibles.

No. The example in "the code" shows an exterior masonry chimney and specifically points to combustible trim 8" from the liner.
However, this does not apply to interior trim.
Maybe Im looking at the wrong code? 2018 International Residential Code.

 

[stoveliker]

I believe NFPA 211 is the one to look at for fire safety.

Anyway, bholler has the certifications. begreen is uptodate too.
I've just learned some things.