To liner a masonry chimney or not

[woodconvert]

I've been reading various threads in here about chimney liners and i'm wondering about the benefits. If you cannot use cannot fit an insulated liner in the existing chimney is there any benefit??. With the flex liners, is it hard to brush with all the ridges??. If I can fit double or tripple wall rigid in there would that be better than insulated flex (if it would fit)??.

I've got a pretty tall chimney (two story house on a 12-12 pitch roof and the chimney is just off center of the house), I run a Jotul firelight and burn 24/7 until spring. I typically sweep the chimney once or twice a year and generally get 3 or 4 gallons of creosote out of it. It draws real good when hot and it's hot more than not. I "think" it's an 8x8 clay liner all the way to the top. With this basic info, would it be worth it to put a liner of some sorts in it???. A typical morning, when it's at it's coolest, the stove top temp is 300-350 and it may take an hour + to get it back cranking to 500-525 (which is all I need to cook us out). Would it be a waste of money or would it make a noticeable difference in performance and creosote buildup??. I don't know anybody who runs a liner in their setup but it sounds like many in here do.

 

[ansehnlich1]

Good question, I have a Jotul Oslo and an outside masonry chimney. My chimney is about 18ft high. Now, my 8x8 clay liner runs up the middle of a brick chase that is 2 feet square, so there's an air pocket surrounding the clay liner all the way up. Wonder if this makes a difference as opposed to the masonry/brick being flat up against the clay liner. My stove seems to work fine, I crack the door for a few minutes on startup, then with a decent load of wood it'll go up to 600F or more, I shut down halfway, then almost the whole way, leaving the draft open just a bit and get decent secondary burns. I'm able to reload in the morning on a good bed of coals but after 8 hours the stovetop temp is down to 200F.

I've wondered if I line my chimney if that would improve the thing too. Don't think I could get insulated liner down there, but at least it would be 6" pipe all the way up, it may improve my draft and allow for a quicker trip up to that 600F degree on the stovetop and possibly a longer secondary burn.

 

[JimWalshin845]

Burning a larger all cast iron stove will take an hour+ to get it to operating temps. Sounds like you are doing it all correctly and I doubt there would be many benefits in lining the flue.

 

[begreen]

woodconvert, is this an exterior chimney? 3-4 gallons of creosote would be a lot for me with an interior chimney.

 

[jbrown56]

Hi, I just got my stove about seven weeks ago after using my old steel box stove for 26 years. For the first five weeks I drafted into an 8 x 12 clay liner and had to leave the side door cracked for 15 to 20 min. to get the fire going . I installed a 20' rigid liner and now only crack the door for 1 to 2 min., close the door and the fire takes off at half damper. I would say it has improved the draft a whole lot. It also seems to burn much cleaner.

Jim

 

[JimWalshin845]

Hi, I just got my stove about seven weeks ago after using my old steel box stove for 26 years. For the first five weeks I drafted into an 8 x 12 clay liner and had to leave the side door cracked for 15 to 20 min. to get the fire going . I installed a 20' rigid liner and now only crack the door for 1 to 2 min., close the door and the fire takes off at half damper. I would say it has improved the draft a whole lot. It also seems to burn much cleaner.
Jim

Jim,
Now I do think you would benefit since you didn't meet the '2X' flue dimension requirements. You were pumping into a 96" sq/in flue and the max would be about 60" sq/in.

Warm burns!

 

[webbie]

A properly built interior 8x8 can be a very ideal chimney, and therefore nothing may be gained from lining it. The only real reason to do so would be if said chimney was built wrong, all cracked inside, didn't pass basic inspections, etc.

 

[woodconvert]

"woodconvert, is this an exterior chimney? 3-4 gallons of creosote would be a lot for me with an interior chimney."

Yes, exterior. Maybe 3-4 gallons is for a year...I don't know but that's consistently what I get. I am going to sweep it one last time tonight and i'll see what I get. (I do recall a fella in a different thread saying he got a wheelbarrow full hh: ). It's basically a masonry chimney inside a bigger masonry chimney. I thought by doing it that way, having an air pocket between the chimneys I was doing the right thing (I should have done tripple wall rigid liner right from the get go though).

"A properly built interior 8x8 can be a very ideal chimney, and therefore nothing may be gained from lining it. The only real reason to do so would be if said chimney was built wrong, all cracked inside, didn’t pass basic inspections, etc."

I agree the sizing may be ideal but I have to believe the last 1/4 to 1/3 of the chimney doesn't get very hot...that's where most of the creosote is at when I do sweep. An insulated liner (if it would fit) wouldn't be much benefit??

 

[Hogwildz]

I ran rigid insulated double wall from first lower flue tile all the way up, with flex from flue tile to stove. My existing chimney is 13" x 13" which is 11'" x 11" interior measurements. I really had to line it with something as that is way too much cross sectional area for my insert's 6" outlet design. Used to be an exterior until a breezeway which is now becoming addition now will envelope all but about 8-10' now. I went with the rigid for reasons of easier cleaning, pre insulated so no added work, and I had the room to do it. I honestly forget the outside dimensions of insulted rigid double wall, next time I am up there I'll measure. If your chimney is 8"x8" outside dimensions.
I am not sure a rigid or flex 6" will fit in there. Y9ou may have to drop down to 5-1/2" or possibly 5". I am guessing your inside measurements are around 5-3/4
to 6"? If you have no draft issues, no flue tile issues, and everything is working well. You might be better off leaving well enough alone. If it works, and works well, don't fix it. I can see how it may be tempting to jump on the liner bandwagon. For safety concerns, for draft concerns, but if your set up is in good shape & works, your ahead of the game. Personally I think a liner is good in many situations, as its just gives me an added feeling of extra protection & safety. Plus its easier to clean than the old direct connect I had. But I had no choice. A properly taken care of direct connect that is in top shape, will give the same performance and prolly last just as long if not longer. The exterior part on yours is the only downfall. But as I said, if it works................
I think its going to be tough for you to get a s.s. liner in that 8" x8". Good luck, either way you decide to go.

 

[woodconvert]

Yeah, I don't HAVE to do anything. It's just i've been reading all the threads on liners and rigid and i'm wondering if there would be a bang for the buck amount of improvement. If no it's no biggie, just curious.

I do believe it's 8x8 outside dimensions but i'll measure it tonight when I sweep it.

 

[mnowaczyk]

Anybody still on this post?

I really want to start burning again. I had a taste of the heat from an insert (with a quick slammer install), and now I just listen to my oil burner all day long while feeling cold.

My chimney is over 40 feet, and appears to be 12 x 12, with probably no more than 11x11 clearance on the inside. I just bought two old inserts that suggest 8 inch connections. I'm wondering if I should just get a connection up to the stright section of chimney, (past the firebox and shelf above the damper), and make a rough connection up there with some type of sheet metal at the end of some flex duct taking me past the fireplace damper. I'd block off the chimney with a "block off" or damper place.

Would this simple solution, and regular cleanings be all I need?

over 40 feet of chimney has some serious pull. Do I need a damper? Or should the damper on the insert be sufficient.

Does this length of chimney make me need a liner more, or less than a shorter chimney?

 

[guest5234]

Since I put a flexible 6 inch liner in my 12 inch by 12 inch chimney the stove burns so much better and hotter.