Can (or should) this smoke chamber be salvaged?

[werhat]

Hi folks,

I bought a 1967 ranch house last year with an original masonry fireplace. The sellers had the flue relined with a stainless steel liner that looks to be about 12" diameter. The liner is (now) clean and in perfect condition. The firebox had a golfball-size hole in one of the front corners that I've patched and still has hairline cracks in the mortar that could be fixed with caulk-tube refractory cement.

I'm confident I can take care of the easy stuff, but the smoke chamber that I'm not sure about. The back corners of the smoke chamber have 1/4" wide vertical cracks where the two sides meet, running most of the way up. There are some defects in the parging near the top and other hairline cracks here and there.

One chimney technician said it was fine to use right away--before I found the golf-ball sized hole he missed. A second company offered to patch the cracks by stuffing refractory mortar in there with a tool on a pole. Of course, there are other defects visible (such as bare cinderblock at the very top), and I'm not confident that a simple patch of those cracks would be a permanent repair. Somehow the material shrank enough to open up those cracks in the first place.

At least one local company offers the Smoktite system, which looks like a good concept if it adheres properly to the underlying material. If it works I still have the original masonry fireplace to use, but the durability would also depend on the care and skill of the installer. The cost would be about $900. Does repairing the original masonry fireplace improve the home's value more than an insert?

Complicating the situation is the fact that the plywood molds under the hearth were never removed. Removing it would require knocking out cinderblocks in the crawlspace to access--not a pleasant proposition. I discovered plywood pieces sticking across the hole--the home inspector didn't bother checking this, of course. I then cemented a cinderblock piece into the bottom of the hole as a plug and filled the ash dump chute with 12" of poured concrete. Altogether there is probably 28" of masonry--firebricks on top of regular bricks on top of two levels of cinderblock on top of 12" of concrete which is then on top of the plywood. I would think the risk of conducting enough heat to start a fire down through all that concrete and concrete block is pretty slim.

Is the Smok-tite system really a permanent repair? In general, is it more beneficial to home value to maintain the original masonry system versus switching to an insert? The heat efficiency of an insert is somewhat appealing. It, too, would draw combustion air from the surrounding space, necessitating an open window, correct?

I did some preliminary search of the forum archives before posting and didn't come up with as much as I'd like, but I'd appreciate a nudge toward existing threads if this has been discussed many times before. Thank you!

 

[HomeinPA]

So you've basically sealed off the opening of the ash dump and the plywood is now not accessible? If that's the case I'd go ahead and back fill the entire hole with block or rubble to the level of the concrete hearth, plug the edges with ceramic wool and fill in the remainder of the hole and then fill in the hearth with firebrick. Or just pour the concrete all the way up.

As for the smoke chamber - It looks like the damper is gone so I'd get ChamberTech and do the entire smoke chamber from the top down. Keep a spray bottle handy and smooth the walls as you come down. If you put it on the right way and proper thickness you can actually achieve a zero-clearance coverage. I use CT2K on all my smoke chambers. There are other similar products out there but I like CT. Keep in mind my comments are based on your photos and assessment. I have no idea what else may be going on that I can't see.

 

[bholler]

Technically to meet code that plywood still needs to be removed. But in reality you have ernough masonry there it is safe. As far as the smoke chamber goes like said above chamber tech or a similar product will work but the one crack is concerning to me. The one with white on it is either very fresh of has air leaking in it. Either way it needs more investigation.

 

[HomeinPA]

I'd also want to know who did the half*ssed job on the liner installation so I didn't accidentally call them back to do something else.

 

[werhat]

So you've basically sealed off the opening of the ash dump and the plywood is now not accessible? If that's the case I'd go ahead and back fill the entire hole with block or rubble to the level of the concrete hearth, plug the edges with ceramic wool and fill in the remainder of the hole and then fill in the hearth with firebrick. Or just pour the concrete all the way up.

That's exactly what I've done. I smashed a couple wads of quick-setting cement on opposite sides of the hole from below, let it set up, and raised a custom-cut cinderblock cap into the hole. Then I smashed more cement all around the border from below and poured about an inch of cement on top. Once that set up, I poured a foot of concrete over it and then parged the top 16" or so to seal any air gaps. My thought is to pour another round of concrete all the way up and then add a firebrick to replace the ash dump door.

As for the smoke chamber - It looks like the damper is gone so I'd get ChamberTech and do the entire smoke chamber from the top down. Keep a spray bottle handy and smooth the walls as you come down. If you put it on the right way and proper thickness you can actually achieve a zero-clearance coverage. I use CT2K on all my smoke chambers. There are other similar products out there but I like CT. Keep in mind my comments are based on your photos and assessment. I have no idea what else may be going on that I can't see.

Actually, the damper is still present. I popped the door out and stuck the light and camera above it. The damper assembly seems to be cemented thoroughly into place, and I don't see how I'd get it out short of cutting it. So while I can see the crack, I can't reach above the first couple feet while I'm kneeling in the fireplace. I definitely can't fit through the hole.

A local sweep carries the Smoktite system which looks similar. There seems to be an investment in tooling required for Smoktite such that it costs about the same to have them do it as to buy the tools! It must be tricky to do a good job while the damper is present.

Technically to meet code that plywood still needs to be removed. But in reality you have ernough masonry there it is safe. As far as the smoke chamber goes like said above chamber tech or a similar product will work but the one crack is concerning to me. The one with white on it is either very fresh of has air leaking in it. Either way it needs more investigation.

It seemed like it should be okay since there's at least 3 times the distance as there is likely clearance in the chimney. There's also framing touching the structure in the crawlspace. I wish I knew how it was constructed above floor level internally.

I can't tell what's going on with the cracks. I did recently hire a "pro" to clean and inspect it. Perhaps the cleaning scraped a previous repair out of the crack. They netted a whole garbage bag full of crap. I also noticed there is a bare exposed concrete block right near the liner, where parging might have been knocked off.

I'd also want to know who did the half*ssed job on the liner installation so I didn't accidentally call them back to do something else.

Okay, I'll bite: what's wrong with that installation? I was wondering how the bottom flange seals to the masonry, or how Chamber Tech or Smoktite would seal to the stainless in a way that is removable, should the liner ever have to be replaced.

 

[HomeinPA]

If that smoke chamber isn't accessible then how would they have set that bottom plate into place? There is supposed to be an airtight seal around the plate, smoke chamber and liner to prevent exhaust gasses from going up the outside of the liner. If the liner had been installed and finished properly there would be no reason to ever replace the liner under normal circumstances. If it did need replaced then the person doing would theoretically be a professional and know what they would need to do to get it back out. I myself have never used a stainless plate at the top of a smoke chamber in a fireplace over the last 20 years. I don't trust that there would be a proper seal between the cement and the steel over time.

I remove dampers and frames all the time when necessary and possible to do safely to do interior fireplace smoke chambers.

 

[werhat]

If that smoke chamber isn't accessible then how would they have set that bottom plate into place? There is supposed to be an airtight seal around the plate, smoke chamber and liner to prevent exhaust gasses from going up the outside of the liner. If the liner had been installed and finished properly there would be no reason to ever replace the liner under normal circumstances. If it did need replaced then the person doing would theoretically be a professional and know what they would need to do to get it back out. I myself have never used a stainless plate at the top of a smoke chamber in a fireplace over the last 20 years. I don't trust that there would be a proper seal between the cement and the steel over time.

I remove dampers and frames all the time when necessary and possible to do safely to do interior fireplace smoke chambers.

The damper frame appears to be cemented and possibly bricked into place. I don't know how they would have placed the bottom plate except possibly by dropping it in from above. There's no sign that the damper frame has been removed, nor does the cement around it appear new. As you can see I'm a fireplace novice, but I don't see how that frame would come out without seriously damaging the brick. The damper flap, of course, comes out easily.

What would have been a good alternative be to the stainless plate? The opening of the smoke chamber is larger than the liner diameter. Wouldn't some sort of adapter be required? (I agree--it's hard to trust the seal between two different expansion coefficients with unknown sealing agent in the joint.)

It's looking more and more like ripping out the liner and installing an insert is the best course of action. There are so many variables, and I can't find anyone who's willing to spend more than five minutes looking at it with a flashlight. This region seems to be a black hole for talented tradesmen.

 

[HomeinPA]

Interior or exterior fireplace?? Is the fireplace on an outside wall or interior wall.....

 

[HomeinPA]

The damper frame appears to be cemented and possibly bricked into place. I don't know how they would have placed the bottom plate except possibly by dropping it in from above. There's no sign that the damper frame has been removed, nor does the cement around it appear new. As you can see I'm a fireplace novice, but I don't see how that frame would come out without seriously damaging the brick. The damper flap, of course, comes out easily.

What would have been a good alternative be to the stainless plate? The opening of the smoke chamber is larger than the liner diameter. Wouldn't some sort of adapter be required? (I agree--it's hard to trust the seal between two different expansion coefficients with unknown sealing agent in the joint.)

It's looking more and more like ripping out the liner and installing an insert is the best course of action. There are so many variables, and I can't find anyone who's willing to spend more than five minutes looking at it with a flashlight. This region seems to be a black hole for talented tradesmen.

There is virtually no way that plate came down from the top and seated squarely like that. If it did then the installer would be rich now from having played the lotto that day and won millions. The damper and frame could likely be removed either partially or completely with a grinder and mallet.

The alternative would be to seal the opening and then cement the entire smoke chamber.

There is no need to rip the entire liner out. Install an insulated liner down the inside through the damper and connect to the stove. You're going to have to insulate it since you have no idea whether the current liner was installed properly.

 

[werhat]

Interior or exterior fireplace?? Is the fireplace on an outside wall or interior wall.....

Interior wall!

 

[HomeinPA]

Well, I'd have to see more pictures of the entire setup but unless there is something really odd about that fireplace I'm fairly certain that myself and quite a few others on here could remove the damper frame, either completely or partially, to allow access and finish the smoke chamber as needed. That being said, I wouldn't do that AND guarantee that installation is done properly unless I pulled the entire liner and made sure the rest of it was put in to code. If I did that then the install would look different all together. To much liability to do it any other way.

If you're considering an insert - which will be more heat efficient in the long run, I'd go that route over spending money on the fireplace.

 

[jzimmer6]

If that smoke chamber isn't accessible then how would they have set that bottom plate into place? There is supposed to be an airtight seal around the plate, smoke chamber and liner to prevent exhaust gasses from going up the outside of the liner. If the liner had been installed and finished properly there would be no reason to ever replace the liner under normal circumstances. If it did need replaced then the person doing would theoretically be a professional and know what they would need to do to get it back out. I myself have never used a stainless plate at the top of a smoke chamber in a fireplace over the last 20 years. I don't trust that there would be a proper seal between the cement and the steel over time.

I remove dampers and frames all the time when necessary and possible to do safely to do interior fireplace smoke chambers.

Hello, I am new to this forum, I am a first time home buyer, My wife and I just bought a house last year that was built in 1941, is a cape cod with a center chimney with 3 flues in it. I have a fire place that I can not use due to cracking of the clay liner. I want to install a liner myself as I don't have the estimated 5 grand. I can't find any good directions on how to install the bottom termination of the liner into my firebox. All I can find is how to install it to an appliance such as a stove or insert. I want to use the original masonry firebox. I am interested in doing away with the damper on the inside of the firebox and would like to install a top mounted damper, so cutting out the damper is not an issue. How do I do this?

Thank you, Jason

 

[Destructor]

What size flue? Often the depth of the smoke chamber is close to the flue size. I can see a skinny person being able to access a 12” deep chamber but how does one access one that is only 8” deep, as many would be if they lead to an 8” X 12 flue. Also the flue can sometimes be quite high up depending on the angle of the chamber walls.

 

[HomeinPA]

Hello, I am new to this forum, I am a first time home buyer, My wife and I just bought a house last year that was built in 1941, is a cape cod with a center chimney with 3 flues in it. I have a fire place that I can not use due to cracking of the clay liner. I want to install a liner myself as I don't have the estimated 5 grand. I can't find any good directions on how to install the bottom termination of the liner into my firebox. All I can find is how to install it to an appliance such as a stove or insert. I want to use the original masonry firebox. I am interested in doing away with the damper on the inside of the firebox and would like to install a top mounted damper, so cutting out the damper is not an issue. How do I do this?

Thank you, Jason

Not to doubt your abilities Jason but to be perfectly honest, the installation you're considering isn't something that is really a DIY project. There are so many considerations that go into relining a fireplace that it makes it practically impossible to go through them all without being there. Not completely impossible, but even for the above average kinda guy....not easily done. I don't know where you are in Ohio or what the particulars are of your home but 5 grand for a fireplace is certainly on the high side of things but again, not knowing your details I won't say for certain. My suggestion is to get a few more estimates and then come back with ideas of what they want to do and we can discuss the virtues of those approaches.

I'd also suggest copying and pasting your question and setting up an original thread so that we don't have 2 conversations going at the same time here and screw somebody up.

 

[werhat]

Well, I'd have to see more pictures of the entire setup but unless there is something really odd about that fireplace I'm fairly certain that myself and quite a few others on here could remove the damper frame, either completely or partially, to allow access and finish the smoke chamber as needed. That being said, I wouldn't do that AND guarantee that installation is done properly unless I pulled the entire liner and made sure the rest of it was put in to code. If I did that then the install would look different all together. To much liability to do it any other way.

If you're considering an insert - which will be more heat efficient in the long run, I'd go that route over spending money on the fireplace.

After considering the options, I'm strongly leaning in the direction of an insert. It seems like it would be a much safer proposition. My insurance carrier (Liberty Mutual) tells me that, so long as it's not the primary heat source in the home, there is no issue with coverage and no increase in premium. The primary heat is radiant ceiling cables and a mini-split heat pump. The heat pump is great in two rooms down to about 25 degrees outside, while the radiant cable heat costs a fortune to run.

I visited the local dealers, one that sells only Quadrafire and the other Regency. I like the look of the Regency CI1250 and CI2600 (catalytic) and some of the more contemporary designs that I found online but can't seem to obtain locally. I'd like to avoid the complexity of the catalyst but don't want a super small insert in my 40x27 fireplace. Anyway, thanks again for the discussion!

 

[HomeinPA]

Good luck. Give us an update and some pictures of the finished project when you can.