Upgrading stove and unsure how to upgrade chimney

[emorems0]

When we moved into this house, they had a 1979 Frontier (I think) with an 8 inch stove pipe connected to a thimble(?) in the masonry chimney. There are 2 terracotta flues, one goes to the stove pipe and I'm not sure where the other goes, maybe to the fireplace? The damper on the dire place is rusted and I'm not sure how to open it.

Our plan was to put in a 6-inch chimney liner for our newer 2015 Magnolia stove. Unfortunately, when I went up on the roof to measure things, I found the masonry chimney is only 5 1/2 ft to the thimble and the terracotta flues are about 6 1/2 x 7 in. I believe our stove needs at least 12ft chimney for proper draft and we won't be able to fit an insulated 6-in chimney liner inside the terracotta flue (and the current flues are all cracked up so we can't use them as is) and so now I'm not sure how to make our chimney work for our stove.

We are pretty competent DIYers but fairly inexperienced with masonry. We planned on repointing the brick in the spring, as it shows some wear on the one side where water runs down from the roof peak. I'm a little afraid of the prospect of removing the terracotta flues, which I'm imagining is going to be the answer we get on the proper way to proceed (my husband is not a fan of that at all). We don't have thousands of dollars to throw at a chimney rebuild, I had budgeted about a thousand dollars for the chimney liner and stovepipe before I realized that probably wouldn't work so I'm hoping that we can figure out a fix that isn't too much more than that, assuming it's something we can do ourselves or with limited hired help.

Hoping the photos load correctly, the thimble is mostly hidden behind a picture at the moment, the flue with all the cracks is the one that goes to the thimble. Any additional info needed, please ask!

 

[bholler]

Yeah the clay tiles will need to come out

 

[emorems0]

I figured there wasn't a way around having to remove the clay tiles... but where do we go from there? Do we need to remove the whole top concrete part and then re-do it (that's very intimidating... and would also affect the unused fireplace flue). I did find this video of a tool that looks like it would make easy work of the tile removal

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I'm just not sure what our final chimney pipe needs are and how to make the transitions at the existing thimble and especially at the top of the chimney... Would I need an insulated, rigid chimney liner for the 5-ish feet inside the masonry chimney (I assume with a Tee coming through the existing 8" thimble)?

How would I extend the chimney height to the necessary 12ft that the stove requires? I'd estimate there will be 2-3ft worth of stovepipe between the stove and the thimble, plus the 5.5 ft in the masonry chimney, which means I still need an additional 4ft of chimney. Wouldn't I need double-walled chimney pipe above the masonry chimney? How would I connect the two different types of pipe?

And how to handle the top concrete part, what if the hole left by the clay tile isn't big enough?

Last question is if I raise the top of the chimney by 4ft somehow, I won't be able to reach it to clean it out from the top and there isn't a cleanout below the thimble. I'll have a 90 at the thimble (I'm hoping I can do 2 - 45s from the stove to the thimble), what's the best way to accommodate cleaning in that situation?

 

[emorems0]

I just had a thought.... the two clay liners are only about an inch or 2 apart and it looks like that's not acceptable anyway. Would it then make sense to knock out both clay liners since they are clearly in the same cavity and try to run an extension from the T (at the thimble) down through the fireplace damper (if I can figure out how to open it) for a cleanout? Then I could probably clean it from the bottom. Any tricks or examples for running a cleanout through a fireplace damper?

 

[bholler]

I just had a thought.... the two clay liners are only about an inch or 2 apart and it looks like that's not acceptable anyway. Would it then make sense to knock out both clay liners since they are clearly in the same cavity and try to run an extension from the T (at the thimble) down through the fireplace damper (if I can figure out how to open it) for a cleanout? Then I could probably clean it from the bottom. Any tricks or examples for running a cleanout through a fireplace damper?

View attachment 306742

That may work but really it's pretty hard to say without being onsite

 

[emorems0]

I think if I could figure out how to remove the fireplace damper, I could do something like this https://www.hearth.com/talk/wiki/make-a-damper-sealing-block-off-plate/
I priced out rigid vs flexible chimney liner and it isn't much more expensive to get 15-ft of flexible liner vs 5-ft of rigid liner and the 15-ft should be more than enough to go from the top of the masonry chimney to a tee at the thimble and then down to this fireplace plate thing... I would just need to figure out how to connect the liner through the plate to a cap of some sort that can be removed for cleaning. Unfortunately, the thread links at the bottom of the post are all broken... it would have been nice to see other examples and how they connected the liner, etc.

I suppose my next task is clearing off all of the stuff that has accumulated on my hearth during the renovation and moving the stove over so I can try and remove the fireplace damper.

 

[emorems0]

UPDATE: I had a chimney service come out to take a look and I'd love to get an opinion on what they said...

Regarding the chimney height, he said as long as the chimney height in relation to the roof is appropriate, they haven't seen issues with not getting enough draft (for reference, my stove manual says we need 12ft for proper draft but we only have about 8ft), so he doesn't think we need an extension of the chimney.

He thinks they can fit a 6" stainless liner inside the existing clay flue, there would be a half inch of clearance and he says we do not need to insulate the liner since it will be insulated by the clay flue. He says it doesn't matter that the clay tile has cracks because it is above the roof line and it's only serving to insulate the steel liner (there may be some lower cracks, but it's hard to see).

Both of the clay flues appear to end at the same level and he thinks they both likely go down to the fireplace but are just 'full of junk' because there hasn't been a proper cap to keep debris out of the flues. He thinks that's contributing to my inability to open the fireplace damper. He says that realistically, we won't be able to get all of that crap out of there, but they'll shovel enough out to get the tee lined up with the thimble (I had assumed there was an elbow at the thimble because the flue seemed to end at that level). Is it really safe to use a woodburner if there is a bunch of stuff just under the tee in the chimney? *added a photo looking into the thimble/tee. Obviously I would make sure the clay flue and thimble area are cleaned before we put in a liner, but I'm concerned about leaving any of this stuff down below the new tee.

Since he says I wouldn't need to add a 4ft extension to the top of the chimney, I could clean the chimney from the top and would have to disconnect the stovepipe at the thimble for cleaning because I wouldn't be able to get a cleanout down below (which is fine if I really don't need the chimney extension).

This is all much simpler (and cheaper) than I had anticipated, so if it's really okay to do it this way, it's what I'd prefer.

 

[begreen]

Cheaper, but a poorer solution. The stove is not being connected straight up, but via stovepipe to a thimble. This is introducing two 90º turns to the flue path and will definitely slow down the flue gases, effectively reducing the equivalent chimney height by 4 ft. This might work for an old smoke dragon with no baffle, but his proposed setup is unlikely to provide sufficient draft for the Magnolia.

 

[emorems0]

I'm not sure if I can attach a PDF, so I may need to figure out how to convert it to an image. This was my plan before talking to the chimney guy, I was worried I was overthinking and overcomplicating things (something I tend to do). It is MUCH more involved than the chimney guy's proposal because we'll have to remove the clay flue liners and figure out how to clean out and open up the fireplace damper in order to put in a cleanout since I won't be able to clean it from the top with a 4ft chimney extension up there. Pricing everything other than the Duravent round-to-oval flex pipe from Rockford Chimney supply so I can have more confidence that it is all compatible, it is more expensive, but my biggest concern is that it is much more labor intensive. We'll have to remove the clay flue pipe and figure out how to get it all cleaned out of the chimney, especially challenging considering there is about 2ft worth of junk piled on top of the fireplace damper that is also rusted shut.

 

[begreen]

That's certainly a lot better but use the chimney pipe manufacturer's anchor plate at the top of the chimney.

 

[emorems0]

That's certainly a lot better but use the chimney pipe manufacturer's anchor plate at the top of the chimney.

View attachment 307325

The transition plate is Rockford's solution to connect chimney liner to class A pipe, I'm guessing I will probably want to add a storm collar or something up there, but I do believe that transition plate piece is the correct 'anchor plate.'

I am not sure how I'm supposed to do a bond break between the pipe and the concrete in this scenario though... the actual logistics of the masonry has me a little stumped. Maybe if I got a short piece of clay liner to form a bridge between the top of the masonry and the transition plate, secured by heat-safe silicone?

And also, the logistics of cleaning out the bottom of the chimney above the fireplace damper...

 

[begreen]

If this is to transition to Rockford supplied class A chimney (Olympia brand?) then it's fine as long as they are providing a complete solution. DuraVent's preinsulated DuraLiner also offers a transition anchor plate solution to DuraVent chimney if comparison shopping. A slip connector makes the actual transition between the liner and the class A.

 

[emorems0]

If this is to transition to Rockford supplied class A chimney (Olympia brand?) then it's fine as long as they are providing a complete solution. DuraVent's preinsulated DuraLiner also offers a transition anchor plate solution to DuraVent chimney if comparison shopping. A slip connector makes the actual transition between the liner and the class A.

View attachment 307326

Yep, it is all Rockford supplied. They were the only place I found that had all of the parts I'd need to go from class A, to rigid chimney liner, to black stovepipe.

 

[emorems0]

Any tips on cleaning out the junk between the thimble and fireplace damper and getting the damper open?

 

[bholler]

Yep, it is all Rockford supplied. They were the only place I found that had all of the parts I'd need to go from class A, to rigid chimney liner, to black stovepipe.

View attachment 307352 View attachment 307353

Why rigid liner?

 

[bholler]

Any tips on cleaning out the junk between the thimble and fireplace damper and getting the damper open?

There is really no way for us to know what will be needed there honestly

 

[emorems0]

Why rigid liner?

A couple of reasons, the first is that I only need 5 or so feet and I haven't been able to find flexible in lengths less than 15ft, that's a lot of waste. The second is that being new to chimney maintenance, I think rigid will be easier to clean and more durable since it is a thicker gauge steel. It is a perfectly straight run so there isn't an inherent need for a flexible liner.

I understand that flexible lining is the new norm and there are a lot of situations that require it, but if a situation doesn't require it, wouldn't it make sense to use a heavier gauge, easier to clean option? Unless I'm missing some downsides? There will only be 1 seam, I'll probably get a 2ft piece and a 3ft piece since they don't sell 5ft lengths.

 

[emorems0]

There is really no way for us to know what will be needed there honestly

Bummer, I had hoped there was some kind of industry trick for clearing debris above a damper. My dad suggested a plumbing auger to loosen things up for a long shop vac hose through the thimble. I'm afraid of what could be in there though... there hasn't been a proper cap to keep animals from going down and getting trapped in there 😫

Could it be possible to remove the damper door with debris on top of it? If was able to figure out how to remove the screw thing, could I shimmy the door/plate out of place without having to fully open it?