never seen before!

[Brian59]

We moved into a new (to us) old house and had a chimney sweep of some experience come out and inspect the chimney. He looked up into it and said he'd never seen "something like that" before. Someone had put 2 6" pipes down the rectangular opening side by side, plugged the bottom just above the damper and then poured concrete down from the top to fill the space inside the chimney and outside the pipes. Then (I think) the pipes were removed. The pipes were a few inches apart near the top of the chimney but pressed together near the bottom with the result that the 2 openings merge near the bottom in a figure 8 sort of shape. The chimney is an interior to the building and in good shape. It extends above the roofline, is longer than 14' and there is little or no creosote buildup inside it. I don't know about distance to combustibles from masonry because my xray vision is not what it used to be.

I'd like to install a wood burning stove venting up the chimney for cheap cheap cheap, 3 times cheap. Can I avoid installing a flue liner and just remove the rusted damper and shove a stove pipe up one of the flues, past where they become a single figure 8 type opening?

Can I run it without a cap for a year?

I've been looking for a "hearth stove" with a rear exhaust that will clear the 34" tall opening of the existing fireplace. Is there a good brand?

I've got a lead on a used Hearth Mate model DFP-1 for $300. Will that fit? There's some sort of plate involved.... but precious little information.

Is there another brand I should look out for in my search? The tiled hearth area in front of our fireplace is 29" deep. The fireplace is another 18" deep to the rear wall. I'd love to get a basic black box but with a flat top and swanky glass door. All ideas welcome and thanks in advance for your help.

 

[branchburner]

Then (I think) the pipes were removed.

I'd like to install a wood burning stove venting up the chimney for cheap cheap cheap, 3 times cheap.

Welcome, Brian. I think you need to know, not think, what material your flue consists of. What did the sweep say? And before you proceed, what will your insurance agent and building inspector say?

You need to balance cheap cheap cheap, 3 times cheap with safe safe safe, 3 times safe. Plenty of stoves to consider, but first things first. Figure out the flue first.

 

[Pagey]

What shape are the chimney tiles in? Was the sweep able to inspect the tile liner with that concrete poured in place? Something to consider is that most stoves on the market today have a 6" exhaust and are thus designed to perform best when vented into a 6" flue/liner. If you do a "slammer" install like you describe, every time you sweep the flue you will need to pull the stove. Keep those things in mind as you proceed, and welcome to the forums.

 

[Brian59]

The sweep didn't say what the liner was made of. He was a good egg and competent but also wanted also to sell me a 1000+ dollar install. "No man is allowed to be a judge in his own cause, because his interest would
certainly bias his judgment ..." and all that rot. My little burst of exuberance shouldn't be taken to mean that I think that cheap should outweigh safe. I'm a family man and safety is of prime concern, cost second ... but a broke family man ... and I need to break even over the run of our first heating season. Otherwise, it's no dice and no stove either. I'll just fire up the oil heat and let it blow through my bank account one gallon at a time.

I looked up the flue again and scratched it with the tip of a screw embedded in a 5' stick. It's not lined with metal. It might be sections of tile. It's not nice and even all of the way up. That's consistent with sections of clay tile I imagine. (oops ... I said the word "imagine" ... am I in trouble for saying that too?) The "section 8" part of the flue where the two more or less cylindrical sections join in the middle extends at least 8' upwards. I could probably get a 6" stove pipe up that far but I'm not sure. If I can and if the flue is a mix of concrete, mortar and tile .... do you think the result might operate safely for one heating season?

 

[Pagey]

It would be interesting to see pics of this particular setup. From what I am reading, I am imaging a masonry chimney with a clay/terra cotta liner, which (it sounds like to me), has been partially closed off/filled with concrete. As in someone put a 'form' of sorts into the flue, then filled it concrete, and then pulled the form leaving behind two round chunks of concrete. Or am I way off base?

I can't see how one would vent a stove into a flue filled with concrete. Please correct me if I am off base here.

EDIT: Wait, I see what you're saying now. They poured the mix on the OUTSIDE of the 'form' and then pulled the pipes/'form'. So whatever was lining the flue before is now covered by the poured mixture.

That's interesting indeed. I would want to find out what material was used, exactly. I'm not sure I'd want creosote deposits building up on something porous, for example.

 

[Brian59]

I can take a picture looking upwards. I'm not sure how much you'll see. Usage has been light but there is a light coating of soot obscuring the details. It looks like 2 circles next to eachother when looking upwards. The concrete was poured into the space between the tile and the masonry, ie. not into the interior of one of the flues.

 

[Pagey]

I wonder why this was done and what the material used was composed of?

 

[midwestcoast]

I thought I followed you & started a reply, until I read: "The concrete was poured into the space between the tile and the masonry, ie. not into the interior of one of the flues." That has me totally lost & if true then disregard everything that follows.
Before getting totally lost I wrote:

The sweep couldn't tell you if the pour-in was concrete, or an insulated concrete-mix? Insulated mixes were used for a while to create smaller flues instead of metal liners. The sweep company or others in the area may know who was doing those type of liners years back & give you insight. You need to know what the material is that was poured/pumped into the flue.
It sounds to me like a previous owner wanted to run 2 flues up, but ran out of room near the bottom & ended-up with a bit of a mess. I hear you want this done fast, cheap and safe, but that's gonna be tough.
You can do what you want, but I wouldn't just slam a stove-pipe up there & start burning.
I can see 1 possible way. IF the "concrete" is actually an insulated concrete mix AND at least one "flue" is pretty smooth, uniform shape/width and right at or slightly over 6" I.D AND it has the required thickness to the clay tiles all around (maybe 1" depends on what the mix is?), you MAY be able to get a 5.5" flex liner inside from stove to cap.
If you don't meet those conditions you will have to bust out that concrete & re-line.
Oh, just thought of another wacky idea. If you can get a 6" liner up past the 2-flue joint, then make a strong block-off plate at the bottom you could then fill that 2'nd flue & half of the jointed section with insulated conc mix poured in from the top & have your one 6" flue. You'd still need to meet most condtions above.
I'd hold-off stove shopping 'til you have the chimney figured out.

Why run without a cap? Caps are cheap & quick to install.

 

[Brian59]

Thanks for all of the replies to my original post. I may have to wait a year to join "the woodstove community" as the general opinion seems to be that it won't be safe without a liner. I've looked up the chimney a few times and down it once. I've listened to what the sweep said and still there's an element of conjecture here about what I'm seeing. I'm guessing that someone installed 2 cylindrical clay liners. They cracked and someone thought it might be a good idea to pour concrete down the chimney, between the masonry and the cylindrical clay liners. Then perhaps some of the clay broke near the bottom and fell out or was removed, resulting in this strange figure 8 look to the flue. I will take a photo and post it here so we can all conjecture together. I know that there's supposed to be airspace between the clay and the masonry.

 

[Pagey]

I think you are definitely doing the right thing by holding off and investigating further. And some pics will help tremendously.

 

[midwestcoast]

+1 You're making the right call. Hold your nose while paying those oil bills for another season.

 

[weatherguy]

Maybe this was their way of repairing a damaged flue. I saw them do this one time on of those this old house type shows where they put a round inflated tube down the chimney then poured some type of mixture down through the top then removed the inflated tube after it set. They did this to make the fireplace workable again whereas if you install a wood stove an insulated liner would probably be sufficient.

 

[branchburner]

I'm guessing that someone installed 2 cylindrical clay liners. They cracked and someone thought it might be a good idea to pour concrete down the chimney, between the masonry and the cylindrical clay liners. Then perhaps some of the clay broke near the bottom and fell out or was removed, resulting in this strange figure 8 look to the flue.

I think that makes sense. You could probably stick a stove pipe up there and burn without incident for some time. The problem that would arise is creosote buildup, and if a chimney fire eventually occurred, how would this unique flue respond? Unfortunately I don't see anyway to predict that, but concrete often cracks at high heat. Maybe it's worth finding a chimney mason to throw in his two cents.

 

[thechimneysweep]

Could be a UL Listed poured liner system,

Like Supaflu, shown at http://www.supaflu.com/products/products.htm

Or Golden Flue, shown at http://www.hickorymountain.com/old_files/gfliner.html

Or Guardian, shown at http://www.virginiachimney.com/procedure.php

How these work: inflatable tubes are inserted down the existing flue, and a slurry is poured around them. As the slurry begins to harden, the tubes are deflated and removed. For fireplace flues, two tubes are often used, side-by-side, to provide the required CSA to handle the exhaust volume. Sounds like in your case the spacers failed somehow, and the two tubes came together at some point (where the two individual 0's become one 8).

Because of the area where your two flues come together, it will be tough to clean this chimney if you vent into it as is. You might consider installing a 5.5" stainless liner through one of the openings, and sealing the other one over at the top.

 

[branchburner]

Could be a UL Listed poured liner system

Is there an easy way for the OP to tell if this is a UL material or simply concrete?

 

[thechimneysweep]

Only by logic: the various slurry mixtures used in the UL systems must be superfine consistency, very liquid when freshly mixed, and extremely light weight in order to be pumped through the application tubes to the chimney top. Anything grainier or heavier would need to be mixed on the roof or carried up in buckets and poured by hand. Anyone with access to the inflatable tubes would have access to the slurry mix, so that's logically what they would use.

 

[Brian59]

I haven't checked in for a while. I can see that you've all been busy speculating etc and have arrived at the same conclusion that I have. Thanks very much for that.

I spoke to a man in our town yesterday whose safety conscious fireman father had a poured chimney liner installed in the house where he grew up. He vented a woodstove through it for decades. It was done as several people have described and the way my chimney is (minus the lack of spacing near the bottom that results in the figure 8 shape). Two inflatable bladders went down the rectangular opening and a slurry was poured or pumped in to the top. Then the bladders were deflated and removed. I don't know what was poured but I think that use of the bladder would indicate someone knew what they were doing and would have used a concrete mix appropriate ... someone else's logic train. I will look at the 3 links someone posted "golden" etc. Perhaps they even have a record of having lined our chimney or someone who could verify the material and method for the insurance company. I could see burning a stove for a few years like this if the insurance company agrees that it's adequate and then going to a stainless liner in a few years if we decide we like burning wood.

Meanwhile, my conversations with local wood stove users make the economics look good. I might burn 3 cords or so, split and delivered for 750. My stove and pipe might only cost 300 or so. Our oil bill looks to 3500-4000 based on past usage. If I could reduce that by 2000-2500 I could reduce my heating costs by 1000 in the first season. I like those economics.

Brian Shriver
lined chimney person and
wood stove user wannabe
Walpole NH

 

[Brian59]

If the flue liner turns out to be adequate then I hope to perhaps purchase a hearthmate stove second hand off of craigslist. Someone is offering one for 300 or so. From what I can tell it's a front loading box, rear venting. It has a pair of legs in the front but in the back it extends through a vertical plate that can be used to seal off the entire fireplace. I think it might fit into or over our opening with some modification. The idea was propbably to vent into the space behind the plate without the need for stovepipe. The owner said that stovepip could be attached. I think I would install one. The damper is operational but damaged. Part of the cast iron "throat" fell off and some masonry behind fell out leaving a 1" by 4" gap between the frame and the masonry. I might remove the damaged damper when I install the stove pipe. I'd appreciate some comments on the feasibility of that. I have some basic concrete and masonry tools and experience having remortared 150' of granite block foundation and having formed and poured steps.

I have attached a diagram of the stove to this post. I don't know if that means it will display. I'll just let her rip and find out.

Brian Shriver
wood stove wannabe
Walpole, NH

 

[70marlin]

I haven't checked in for a while. I can see that you've all been busy speculating etc and have arrived at the same conclusion that I have. Thanks very much for that.

I spoke to a man in our town yesterday whose safety conscious fireman father had a poured chimney liner installed in the house where he grew up. He vented a woodstove through it for decades. It was done as several people have described and the way my chimney is (minus the lack of spacing near the bottom that results in the figure 8 shape). Two inflatable bladders went down the rectangular opening and a slurry was poured or pumped in to the top. Then the bladders were deflated and removed. I don't know what was poured but I think that use of the bladder would indicate someone knew what they were doing and would have used a concrete mix appropriate ... someone else's logic train. I will look at the 3 links someone posted "golden" etc. Perhaps they even have a record of having lined our chimney or someone who could verify the material and method for the insurance company. I could see burning a stove for a few years like this if the insurance company agrees that it's adequate and then going to a stainless liner in a few years if we decide we like burning wood.

Meanwhile, my conversations with local wood stove users make the economics look good. I might burn 3 cords or so, split and delivered for 750. My stove and pipe might only cost 300 or so. Our oil bill looks to 3500-4000 based on past usage. If I could reduce that by 2000-2500 I could reduce my heating costs by 1000 in the first season. I like those economics.

Brian Shriver
lined chimney person and
wood stove user wannabe
Walpole NH

I feel if you can find a good price on a flex liner, go that route. spend the money on the liner save money on the stove.

 

[branchburner]

The "section 8" part of the flue where the two more or less cylindrical sections join in the middle extends at least 8' upwards. I could probably get a 6" stove pipe up that far but I'm not sure.

Have you thought anymore about making this connection? First off, you might want to get a section of ss pipe (maybe used?) instead of regular stovepipe. What you have is basically a partial 6" liner, and you are going to try to turn it into a full 6" liner, so you want to use materials consistent with that. Regular stovepipe is not.

Secondly, if the connection is not tight where you intend the metal pipe to mate with the existing flue/liner eight feet up, won't that effectively be the same as having a leaky/cracked liner? I'm not saying your hybrid metal/cement flue won't be safe, just saying you want to explore all the potential challenges in making it so.

 

[branchburner]

The idea was propbably to vent into the space behind the plate without the need for stovepipe. The owner said that stovepip could be attached. I think I would install one. The damper is operational but damaged. Part of the cast iron "throat" fell off and some masonry behind fell out leaving a 1" by 4" gap between the frame and the masonry. I might remove the damaged damper when I install the stove pipe.

You definitely don't want to vent without a pipe. Taking the damper out is fine, but regarding masonry damage: make sure the masonry is in good enough shape to be protecting whatever is behind it. That stovepipe will be throwing a lot of heat. What kind of shape is the smoke chamber in, or is that all filled in with the poured liner material? Would love to see a pic of this!

I don't know a thing about that stove, but for a few hundred more you could find a newer, better, more efficient heater.

 

[Brian59]

I'm not sure what you mean by full and partial liner. I'd like to understand how you are using those terms.

smoke chamber? .... The fireplace looks quite normal below the damper except where the cast iron piece is broken off. The concrete liner starts a few inches above the damper and fills most of the space. There's just enough room for the damper to swing upwards when it opens. I tried to take a picture but couldn't get anything worth looking at. Maybe my wife's little camera would capture more.

I guess the general feeling on this forum is that stainless is best. I thought it might be interesting to get a rep from one of those 3 companies still doing poured liners to express their opinions on this forum about the benefits of their poured liners.

I think that I will pass on the $300 used stove. I may see if she'll sell at 200. I've been shopping around but have expensive tastes and ended up wanting a 1500 soapstone stove. What a beauty and it fit our hearth so nicely. I'd welcome ideas about where to go for a new stove of a basic nature. I'd like a front loading unit with a glass door, a flat top and a rear exhaust and more wide than deep to fit our hearth. Any suggestions? Is there a post that includes good links to vendors?

Regards,
Brian Shriver
Walpole NH

 

[branchburner]

I'm not sure what you mean by full and partial liner. I'd like to understand how you are using those terms.

What I'm saying (based on what you're saying!) is you have a partial liner, meaning the existing length that is 6" is not the full length, it is just the upper part. The remaining lower part is that weird "section 8" shape, which will be tough to connect to a stove pipe. As you stated, you will have to shove the pipe way up and hope for a good connection. Once you make that connection, only then will you have a complete or "full" liner. It will consist of two sections: one metal pipe, one cement pour-in.

So "full liner" meaning a continuous, unbroken path for gases to travel all the way from a bottom connection at the stove to the very top of the chimney. Does that make sense? I hope my mental image actually correlates with your chimney! Visit a few stove shops and start picking the brains of whoever you can. Maybe take a drive up to Woodstock Soapstone in West Leb.

PS - Did you see my PM about the free wood?

 

[midwestcoast]

I guess the general feeling on this forum is that stainless is best. I thought it might be interesting to get a rep from one of those 3 companies still doing poured liners to express their opinions on this forum about the benefits of their poured liners.

I think that I will pass on the $300 used stove. I may see if she'll sell at 200. I've been shopping around but have expensive tastes and ended up wanting a 1500 soapstone stove. What a beauty and it fit our hearth so nicely. I'd welcome ideas about where to go for a new stove of a basic nature. I'd like a front loading unit with a glass door, a flat top and a rear exhaust and more wide than deep to fit our hearth. Any suggestions? Is there a post that includes good links to vendors?

Really I think the preference for stainless steel liners is due to the economics. As far as I know there aren't real prolems with the pour-in liners, just that mostly the industry has moved on to the simpler installation of SS liners. Maybe there's something I don't know.

Good quality stoves at reasonable cost: Englander, Drolet..., plenty really, just try some searches here. If you're looking for soapstone, there are many very satisfied folks here with Woodstock stoves.