6" stovepipe into 8" thimble

[wtyamamoto]

In setting a new stove where an old one was, I was wondering if the above is possible. The exising mansonry chimney has an 8" steel thimble mortared in with the 8" pipe extending out and to the stove. My original plan, as recommended by everyone (thank you), was to run the 6" from the stove to the entry and use an adapter at that point.

I was wondering, is there a method whereby I can run the 6" all the way through the thimble to the flue and seal or gasket around the 6 inch?

Thanks for everyone's collective wisdom!

Wayne

 

[elkimmeg]

That is also a compliant way of doing it. Can you cut out the thimble and then cement in a 6" thimble in its place?

 

[wtyamamoto]

Hello elkimmeg,

I guess I could, but if possible I would prefer not to. In the event that the existing chimney can't draft properly, I would be going with a stainless liner anyway and that would double the work (am I wrong?). Is there a way to seal the 6" pipe in the 8" thimble - a non-mortar, easily removed way?

Wayne

 

[BrotherBart]

I burn into one just like it except the thimble is clay. I have a six to eight inch adapter inside the thimble with the eight inch part exiting even with the clay flue tile. I run the six inch pipe the length of the thimble and it is attached to the adapter. With the adapter wedged in tight it cuts down on the chimney sucking air around the pipe and up the chimney. Of course I also have the six inch pipe running through one of those doughnuts on the inside wall and it is sealed too.

If I get my self moving I am going to go through the pain of installing a liner and tee in the thing in September. I do not look forward to installing the tee in that thing. Not to mention that the thimble exits four feet above the cleanout. I don't know how the heck I am going to cap the bottom of that tee or get the cap off for clean-out working through that little clean-out door hole.

But I bet Elk is going to suggest again that I knock a hole in the back of the chimney. No way GI.

 

[Todd]

I burn into one just like it except the thimble is clay. I have a six to eight inch adapter inside the thimble with the eight inch part exiting even with the clay flue tile. I run the six inch pipe the length of the thimble and it is attached to the adapter. With the adapter wedged in tight it cuts down on the chimney sucking air around the pipe and up the chimney. Of course I also have the six inch pipe running through one of those doughnuts on the inside wall and it is sealed too.

If I get my self moving I am going to go through the pain of installing a liner and tee in the thing in September. I do not look forward to installing the tee in that thing. Not to mention that the thimble exits four feet above the cleanout. I don't know how the heck I am going to cap the bottom of that tee or get the cap off for clean-out working through that little clean-out door hole.

But I bet Elk is going to suggest again that I knock a hole in the back of the chimney. No way GI.

Forget the tee, just bring the liner right through the crock. That's what I did and cleaning is a breeze. I sweep the chimney, then disconnect the stove pipe at the thimble and all the soot is right there.

 

[clambdin]

I had the same setup, I just made a 6inch thimble by taking a length of 8 inch pipe and centering a length of 6 inch pipe inside of it I then poured mortar in the gap between the 6 an 8 inch,then just slide the whole thing thru your existing thimble hole, works like a charm just let the mortar set up for several days before you install it.

 

[BrotherBart]

Forget the tee, just bring the liner right through the crock. That's what I did and cleaning is a breeze. I sweep the chimney, then disconnect the stove pipe at the thimble and all the soot is right there.

Oh I have dreamed and dreamed of doing just that. But with only a 7 inch width on that flue tile I would put a kink in that liner that nothing could get through when I did the 90 degree bend at the thimble.

 

[elkimmeg]

BB I wish we lived closer I would surely help you with that liner That is if we could get past one liners. old war stories and the occasional brewski. I promise you we would get it installed and have plenty of time to Kick back. Got any mushrooms growing around there? Now if Warren can Convince Christy to help. I'm there and I agree she is still hot. and now available.

We probably could get Corie if the misses lets him off the lease. He is legal so we can give him a Sam Adams. I would send Lime 4x4 an invitation but it would get lost in the mail. We could get Mo there but he would analize it to death and nothing would get done. But he sure could record the goings on and put quite a spin to the events
On the way I would stop by harry' establisment pick up a bag or motar and a few bricks and another concrete cutting wheel for my grinder a so I can cut that cleanout in, brick up the old one and make the installation child's play

MSG would be invited with two stipulations, he brings rocky mountain high and the two coor's light twins to assist us.

 

[jabush]

Forget the tee, just bring the liner right through the crock. That's what I did and cleaning is a breeze. I sweep the chimney, then disconnect the stove pipe at the thimble and all the soot is right there.

Oh I have dreamed and dreamed of doing just that. But with only a 7 inch width on that flue tile I would put a kink in that liner that nothing could get through when I did the 90 degree bend at the thimble.

The tee at the bottom of my liner does not have the cap on the bottom. The installer said he left it off so I could sweep my liner into the original cleanout for the chimney. The tee is around 2-3 feet above the cleanout and the door fits tightly.

Is this wrong?? Should I have the cap on the bottom of my tee?

I also have a tee connected to the back of my stove (capped of course) for easier cleaning inside.

The above setup worked well last year, just now wondering about the tee at the bottom of my liner.

Sorry for the hijack....

 

[elkimmeg]

The Tee is designed to have a cap installed. I supose if the ash dunp area was completely air tight and that it does not open to other flues like a furnace/boiler it would be ok Typical of chimneys having multi flues. is the ash dump area is an open area. Each flue should be partitioned off, But a bit of cheating occured and partitions were omitted. Your stove could be opperating ok but untill you seal or cap that bottom tee. You will never know if a sealed draft system opperateds even better and your stove more effecient.
It is possible that open tee is drawing in air. Any air drawn in can inhibit draft and stove preformance. If in an open ash dump area, the tee opening, could lessen the draft to other appliances connected to that chimney. Back drafts are possible. Also dependent is how tight a seal for all ash dump doors Me I caulked them tight. They are notoreously leaky..

 

[jabush]

Thanks Elk. Chimney is for the stove only...20' tall and drafts good. At this point I guess my best bet is to caulk the door shut and cut the seal when it's time to sweep. I don't know how I would get to the bottom of the tee (to install the cap) from the cleanout door.
Prior to having the chimney lined I did have back puff issues on very windy days if I didn't wedge something against the cleanout door to keep it shut tight. So I know what you're saying there.
I'm thinking if I seal the door I can accomplish the same thing as adding the bottom to the tee. Not the perfect fix, but your suggestion may improve my draft. And caulk is cheap.

Thanks again...

 

[BrotherBart]

You're right Elk it would be a good time. I am afraid we would spend so much time laughing we might not get the job finished.

What I am going to try is attaching a piece of six inch pipe on the bottom of the tee and capping it. Essentially just extending the bottom of the tee down 48". That also gives me a way to just stick a trash bag under it for cleanout instead of having to scoop up the stuff from the bottom of the cleanout chamber.

That will also give me something to work with from the bottom when I align the tee during installation.

Like everything else, it looks good on paper.