Chimney Liner Alternatives...Please help!

[webby3650]

If the flue is nice and straight I bet an insulated 6" liner would go down it! If you used 1/4" foil faced insulation and got the mesh nice and tight it would go. Use a nose come with a pull rope on it. Two people could get it in there. I've done it quite a few times on flues this size before, but the tiles have to be aligned pretty well, and the stars.

 

[webby3650]

You could slightly ovalize it too, like was mentioned above. It works pretty well. After its all assembled, you can actually walk on it, it will ovalize it every so slightly.

 

[avc8130]

If the flue is nice and straight I bet an insulated 6" liner would go down it! If you used 1/4" foil faced insulation and got the mesh nice and tight it would go. Use a nose come with a pull rope on it. Two people could get it in there. I've done it quite a few times on flues this size before, but the tiles have to be aligned pretty well, and the stars.

You could slightly ovalize it too, like was mentioned above. It works pretty well. After its all assembled, you can actually walk on it, it will ovalize it every so slightly.

I'm liking a combination of these 2!

Since it is so close to fitting, and definitely the most affordable option, I think starting with a 6" insulated round liner and ovalizing to fit is probably the best idea to date!

ac

 

[webby3650]

 

[elmoleaf]

Is the chimney on an outside wall or internal to the house?
I'd leave terra cotta and install un-insulated liner, with good block off plate at bottom and some roxul stuffed around top.

 

[avc8130]

Is the chimney on an outside wall or internal to the house?
I'd leave terra cotta and install un-insulated liner, with good block off plate at bottom and some roxul stuffed around top.

Outside wall.

ac

 

[infinitymike]

I have no experience in this but just my common sense knowledge says don't knock out the flue or pour any insulation in there because even if the realtor says that, they may put in a contract that he has to remove it before they close. Breaking out the clay pipe is hard enough and now you will have a metal liner and insulation jammed in there, even harder.

Spend the money and go for the oval pipe. It's only a 12' run. Why start messing with ovaling it yourself and risking screwing it up.

" the bitterness of poor quality last far longer than the sweetness of low price "

 

[Bluerubi]

Frankly you guys have pretty much the same weather as we do and my two un-insulated liners in tile lined chimneys rock. At least they have for the last seven years.

The most important stuff happens down at the bottom. Good stove, dry wood and good burning habits.

Agreed. Even in southern NH with an outside brick chimney I have had no issues with my uninsulated steel liner.

 

[Huntindog1]

If your in a bind you can go without any insulation. I run my stove in a clay lined over sized masonry flu. I am still able to get it warmed to create draw.

Your going with a 6" liner made for a 6" outlet stove its gonna be able to warm that flue easy and create draw. I would be more interested in adding the extra height to the flue to give you like a 16 foot flue instead of the 12 foot you got.

Then lastly your burning an EPA high efficiency stove thats gonna be burning so clean that you gonna get very little deposits. As these stoves wont burn with out good season wood anyways. I say this as one reason in the old days of the smoke dragons was to use an insulated flue to keep as much heat in the flue all the way to the top as to keep deposits from sticking to the inside of the flue as there was so much unburned stuff getting up the flue from those old smoke dragons stoves of the past. These new stoves you would really have to be negligent to create conditions like that.

 

[clemsonfor]

i would just go with a 6" liner no insulation and insulate the bottom and top of chimney with roxull as far as you can stuff down, or fiberglass, neither will burn in the top 5 feet of the chimney, well roxul, never but your chimney top wont get to hot for glass either.

 

[arro222]

i would just go with a 6" liner no insulation and insulate the bottom and top of chimney with roxull as far as you can stuff down, or fiberglass, neither will burn in the top 5 feet of the chimney, well roxul, never but your chimney top wont get to hot for glass either.

I'm helping a buddy install a wood stove in his traditional masonry fireplace. He understands it is best to install an insulated liner and wants to do everything tip top best.

We checked his current flue tonight and we have our first hurdle.

The current flue is terracotta liner. Inside dimensions are 6.5 x 11.5 rectangular.

The stove he has chosen requires a 6" flue.

His idea is to smash out all of the terracotta tile and install a traditional flex liner with wrap insulation.

I think we should leave the terracotta lining since it is in good shape and run a flex liner with pour in Vermiculite insulation.

Is one plan better than the other?

Thanks for the quick help!

ac

Depending on the stove, you may be able to use a 5.5" liner if it's a dead smooth rigid type. Then you can either wrap the insulation or pour loose vermiculite w/o breaking up the current tile. Stay away from the pour type insulation that you mix water with. Rigid liners are smoother so they can flow more with less diameter.

 

[Heatsource]

I am the naysayer I guess. Use poured in insulation. Bust those tiles out of there and you ain't gonna believe what happens when you try to sell that house to somebody that doesn't want a wood stove in that fireplace.

\

typically need to remove the damper, and section of back plate.
no matter what, it cant be used as an open FP again...

 

[webby3650]

Is the chimney on an outside wall or internal to the house?
I'd leave terra cotta and install un-insulated liner, with good block off plate at bottom and some roxul stuffed around top.

If its uninsulated, it might be better to block it completely at the top instead of the block off plate. That way the liner will stay hotter. It proba

\

typically need to remove the damper, and section of back plate.
no matter what, it cant be used as an open FP again...

The firebricks can be replaced and a lock-top damper installed if an open fireplace is ever wanted again.

 

[avc8130]

So for the fun of it he called the local Jotul dealer today to get their opinion.

"Insulation? For what? We never insulate liners and never have any problems!"

LOL

ac

 

[webby3650]

So for the fun of it he called the local Jotul dealer today to get their opinion.

"Insulation? For what? We never insulate liners and never have any problems!"

LOL

ac

Well, they are crazy! It makes a huge difference on most installs. They are just trying to cheap it up, I bet they are cheaper than other stores that actually do it right.

Most of the time the clay flue liner is cracked, therefore insulation is required to meet code. It's uncommon to see a flue that doesn't have a nice big crack going from top to bottom. Most uninsulated liners are dirtier than insulated liners. When I look down a flue I can usually see where the insulation stops a foot or so down. It'll be all dust up to that point, then it's black a flaky.

I don't think it's a must on all installs, uninsulated is better than no liner at all. If it doesn't fit, it doesn't fit. But if it does, why not? It's safer and more efficient. Just my 2 cents.

 

[avc8130]

Well, they are crazy! It makes a huge difference on most installs. They are just trying to cheap it up, I bet they are cheaper than other stores that actually do it right.

Most of the time the clay flue liner is cracked, therefore insulation is required to meet code. It's uncommon to see a flue that doesn't have a nice big crack going from top to bottom. Most uninsulated liners are dirtier than insulated liners. When I look down a flue I can usually see where the insulation stops a foot or so down. It'll be all dust up to that point, then it's black a flaky.

I don't think it's a must on all installs, uninsulated is better than no liner at all. If it doesn't fit, it doesn't fit. But if it does, why not? It's safer and more efficient. Just my 2 cents.

I agree 100% with you. The plan is an insulated liner. At this point we are down to 2 options:

1. Oval rigid insulated liner.
Advantages: It fits! Rigid=smooth.
Disadvantages: Figuring out how to fit through the damper area. The liner will need to "jog" through this area down to the tee. Cost: this thing is PRICEY. What to do about extending the top. Do we just extend 4' with an oval rigid? That's gonna look weird and I don't see a cap available.

2. 6" Round flex w/ insulation wrap.
Advantages: Cheaper. Flex should jog through the damper area with no problem. We can transition to a 4' rigid piece at the top for the extension and use a common cap.
Disadvantages: We may have to ovalize a tad.

ac

 

[Mitch Newton]

How about a pellet stove and liner? 4". Sorry, I know that's heresy for wood burners

 

[avc8130]

How about a pellet stove and liner? 4". Sorry, I know that's heresy for wood burners

My buddy is an arborist by trade...

ac

 

[webby3650]

My buddy is an arborist by trade...

ac

And he wants heat!

 

[webby3650]

Ovalizing it a tad on site is no big deal at all. Ask the chimney liner manufacturer if its ok. National chimney supply doesnt have a problem with it.They will ovalize the very same liner that comes round if you want. They use a big fancy machine, but as long as your careful its not hard. Just make sure you don't smash it, apply even pressure and you'll be fine.

 

[Heatsource]

If its uninsulated, it might be better to block it completely at the top instead of the block off plate. That way the liner will stay hotter. It proba

The firebricks can be replaced and a lock-top damper installed if an open fireplace is ever wanted again.

I suppose you are right, but
most we deal with are heatilator types, you cut out lots of metal that isn't practical to fix after the fact.

 

[begreen]

I agree 100% with you. The plan is an insulated liner. At this point we are down to 2 options:

1. Oval rigid insulated liner.
Advantages: It fits! Rigid=smooth.
Disadvantages: Figuring out how to fit through the damper area. The liner will need to "jog" through this area down to the tee. Cost: this thing is PRICEY. What to do about extending the top. Do we just extend 4' with an oval rigid? That's gonna look weird and I don't see a cap available.

DuraLiner has several pieces to complete there system. Download the M&G DuraLiner catalog to look at options. Use a section of oval flex to round right above the damper area and then to the stove flue collar. The top of the chimney is a bit more of a problem. You will need to transition to round at the top. This might require busting out the top tile liner. Once you are at round you can extend it with a length of round rigid. M&G has an extend a cap system for this. Instructions are in their Duraliner install manual. If you chose to use DuraLiner, call M&G tech support. They will verify the pieces you need to order. Sean at dynamitebuys.com is pretty helpful too.

So for the fun of it he called the local Jotul dealer today to get their opinion.

"Insulation? For what? We never insulate liners and never have any problems!"

The chimney is short and exterior. It is going to need all the help it can get to draft well. Insulate, regardless of the chosen option. And plan on putting in a damper sealing block off plate too.