How long does your fireplace burn?

[jinman]

JB and Randall, I had not thought of using the inside of the clay tiles to route a chimney. I guess I'm confused, because the SS pipe you are talking about would be mostly below the firebox, surrounded by the fireplaces filler brick. Once the pipe is inside the clay tile, there would be no need for it to run all the way to the top. It would just dump the exhaust gasses into the regular chimney. It only needs to extend into the smoke box above the current damper. Is that right? If the main fireplace is not in use, I'd just close the damper so no gas would backflow into the upper part of the house.

I may have enough room in the back part of the firebox to route a SS pipe that would accomplish this and not interfere with the normal fireplace. It would enter the basement wall below the raised hearth and into the fireplace base structure. Then it would turn upwards and into the back of the firebox. The middle of the base structure below the firebox is mainly just loose brick with little or no mortar. They are just stacked inside the fireplace wall. This should allow easy removal so the pipe and additional support can be installed. Only a small section of the current basement wall would be disturbed.

 

[Egon]

Once the pipe is inside the clay tile, there would be no need for it to run all the way to the top. It would just dump the exhaust gasses into the regular chimney. It only needs to extend into the smoke box above the current damper. Is that right? If the main fireplace is not in use, I'd just close the damper so no gas would backflow into the upper part of the house.

Check out your local codes first. Where I am this would not acceptable. Each appliance must have it's own separate flue.

 

[jinman]

Check out your local codes first. Where I am this would not acceptable. Each appliance must have it's own separate flue.

Egon, we have zero codes here with the exception of septic systems. Even so, I would not do something that is not considered safe, like dumping the exhaust directly into the current firebox. If it's above the current damper and into the smoke box, I just don't see how it could ever be a problem, cold air and reverse flow are not a problem with this fireplace in my experience. Of course, I could put the chimney on the outside of the current fireplace chimney, but it would be an eyesore in my opinion. I think I'd tear out the fireplace and rebuild it before I'd do that. As JB noted, it would be a simple thing to route a 4" pipe up the inside of the current chimney tile if I had to. Dealing with bypassing or going through the current firebox is the biggest problem.

 

[JB4310]

What I was talking about was a separate SS 1 pc flex stove pipe from the basement to the crown. Most of that chimney is hollow chase. the big problem is finding a way around the firebox, looking at the pics of yours it may not be possible if they made the firebox as big as possible.
Your only hope would be in one of the outside corners behind the the back corner of the fire brick, it would require opening the veneer on the out side of the chimney to clear a path for the new pipe, it doesn't need much room but that might be some valuable real estate, making it impossible or at least cost prohibitive.

What Randell was referring to is if you wanted to put an insert in, or for sure if you put a wood stove in the existing F/P, you would have to run a SS pipe up the flue, smaller than the 12x12 or 8x12 existing clay liner, probably ~6" round.
Not for draft or safety but to keep the stack temps high enough, with the larger flue the temps would be to low and that causes a few different problems when using modern solid fuel burning stoves.

Regardless of codes you don't want to share a flue, I've seen hokey set ups where they've run a steel pipe right thru a fireplace, but you're NOT gonna do that. Seen others where they sacrifice the F/P on the upper floor to have a working flue in the lower floor, that's pretty easy but requires running a flue right thru the fireplace then bricking up the front, and I know you're not gonna do that either.

The easy thing to do is, if you can track him down, ask the mason who built it if there is any room in there, he should be able to tell you, unless you have some more detailed pics.

Not to rub it in, but it would of been so easy during construction, that chimney is big enough for 3 flues.

 

[jinman]

Not to rub it in, but it would of been so easy during construction, that chimney is big enough for 3 flues.

JB, you can rub it in, but you'll have to stand behind me in line. I've been kickin' my butt continually since I built this house for not incorporating another flue into the fireplace casement. As a matter of fact, the casement is not hollow. The builder and masons ordered "filler" brick to lay inside the casement all the way to the top. Essentially, this fireplace is solid brick from the base to the top, but I don't think all the filler brick were mortared in as the outside brick and the firebrick. Some mortar was used for stability, but essentially the inside brick are just sitting in there with little to hold them in place.

I should have taken more pictures at the time, but here are a couple more. As you can see, there is only about 4" on each side of the firebox and none behind the firebox. Also in the outside picture (2nd one), the stack of brick in the middle are not the same as the casement brick. They are cheap brick used to fill in the middle of the fireplace stack and around the tile flue. In the last photo, you can see the huge tile used for the stack. If I had asked for it, we probably could easily have made the fireplace a bit wider and put in a second flue or used smaller tile and allowed for two flues. Hindsight is so wonderful.

 

[JB4310]

As a matter of fact, the casement is not hollow. The builder and masons ordered "filler" brick to lay inside the casement all the way to the top. Essentially, this fireplace is solid brick from the base to the top, but I don't think all the filler brick were mortared in as the outside brick and the firebrick. Some mortar was used for stability, but essentially the inside brick are just sitting in there with little to hold them in place.

As you can see, there is only about 4" on each side of the firebox and none behind the firebox.

You know your house better than anyone, but that's not normally how it's done. Typically there would just be a single wythe going up one or both sides of the flue to stabilize, those bricks would be mortared, to fill that whole core with dry laid masonry units would/could collapse the throat at the top of the FP under the weight. When the bricks are mortared in they transfer the weight to the foundation via the veneer.

Do you remember how they did the floor of the firebox, could of been done a couple different ways, usually double course walls up to the bottom of the fireplace and a bed of cement on a steel pan resting on the inner course. or a block or brick frame work coming all the way up under the floor of the fire box.

Either way there should be plenty of straight shot in most of that core, except at the fireplace, though that first pic you show here has some promise, you can see there is nothing at the back but at the inside corner where the floor of the fireplace is the narrowest, shows some space there. Hard to tell how much space, it's ok to ovalize stove pipe to a certain degree to fit a narrower space.

Anyway It might be doable but would require some intrusive and destructive inspection, which could be done from the outside or maybe the basement.

Your flues look large, hard to tell by pics but maybe 12x16 or 16x16?
Around here new FP usually has 12x12, 25 years or older and all are 8x12.

Just a couple of show off pictures of me on a huge house, I use to do alot of chimney repair, not as much anymore.

JB.

 

[zzvyb6]

I had to replace the cement cap on my fireplace chimney this summer. Its a dual flue for upstairs and downstairs fireplaces. While I was at it, I made a copper Mayan type of chimney cap out of sheet copper and copper water pipe as the support structure. It glistens in the bright sun and I can see it for quite a distance. The water pipe and elbows are Home Depot. The sheet copper is from a 3' x 10' piece of 16 guage roofing material available from a supplier just down the road. I finally learned how to solder copper pipe....

 

[jinman]

You know your house better than anyone, but that's not normally how it's done. Typically there would just be a single wythe going up one or both sides of the flue to stabilize, those bricks would be mortared, to fill that whole core with dry laid masonry units would/could collapse the throat at the top of the FP under the weight. When the bricks are mortared in they transfer the weight to the foundation via the veneer.

JB, one of the original pictures I posted may have a clue. Above the fireplace in that picture, you can see that the filler brick are indeed mortared in as you suggested. I was not there for the complete construction of the fireplace and only saw the beginning, middle, and end. I do remember seeing loose brick filling the middle below the firebox, but I may have been mistaken as to the mason's methods. They may have just put loose brick in and then applied mortar similar to a grout over the course of brick and then added a second just to save time. There's no need to have neat brick laying in the middle of the fireplace. They may have just opted for the quickest method. I do remember that the contractor had to go and get an extra two stacks of filler brick because there were not enough to fill the void.

Also, I believe there is no metal pan below the firebrick. I don't remember seeing one, but I do remember some type of special mortar for the firebrick and they may have used something similar to make a mortar "pan" below the firebrick and on top of the solid filler brick structure. Looking at the linked picture above, you can see that the side walls of the finished firebox are set in from the edges of the firebox floor seen in a previous picture. I believe the side walls are double thick firebrick laying on their edges. The top of the firebox's brick veneer sits on a steel angle iron similar to garage door openings in brick veneer houses. I just don't think there is any open void inside this fireplace structure except the smokebox and flue pipe. All the rest is solid brick and will not lend itself easily to modification.

My wife has suggested that we might add a flue to the side of the existing fireplace and brick up around it so that the entire fireplace chimney tower is a foot wider. If we could find matching brick and a good mason, that might be the easiest way to proceed.

 

[jinman]

I had to replace the cement cap on my fireplace chimney this summer. Its a dual flue for upstairs and downstairs fireplaces. While I was at it, I made a copper Mayan type of chimney cap out of sheet copper and copper water pipe as the support structure.

Bill, that certainly is a beautiful setting you have for your house. I love houses at the tops of hills with lots of landscaping like yours.

I'm curious about your cap. Does the smoke vent out the ends and the top is solid? It sure is bright, but will soon have a nice green patina.

 

[JB4310]

It sure is bright, but will soon have a nice green patina.

At the risk of sounding like a "know it all" this is another of the few areas I have a little experience in the construction and restoration fields.

I do a tiny amount of copper work, like gutters and leaders for the churches I work on. I can solder factory made copper gutter/leader components together, with a little bit of custom bends etc. I solder with a torch.
The real pros do it with heavy irons that they heat with open flames or special kettles, that's a skill and a half, it will blow you away what a skilled tinsmith can do with sheet metal.

Anyway what I'm getting at is, you say it will patina soon?
Don't hold your breath, none of us may still be around by the time that new copper turns green, it could take decades! It will just turn brown after a season or 2 and stay that way for a long, long time.
To get to a full, all green patina could take 40-50 years.

You can speed up the process by treating the metal with an acid mix. Duplicating all those years worth of environmental fall out "acid rain"

Sorry Jim, Now this is way off your OP, just something that sparked my interest

Oh and yeah, A beautiful place you have there zzvyb6.

JB