Class A inside masonry chimney
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snowtime
Minister of Fire
I only have a 15 foot run, so the install wouldn't be too bad. I have a line on some for basicly free. Cheaper than buying insulation for my rigid liner that is already installed.
Renovation
New Member
Free is good, and I don't see why not. Anyone?
One caution--my understanding is it is okay for Class A to touch masonry, but *not* insulation, as that can cause hot spots and failure. So don't jam any insulation in there within 2" of Class A pipe.
One caution--my understanding is it is okay for Class A to touch masonry, but *not* insulation, as that can cause hot spots and failure. So don't jam any insulation in there within 2" of Class A pipe.
offroadaudio
New Member
We need verification from an expert here, but I think the manufactures of class A forbid it's use as a liner inside a masonry chimney.
Therefore, also a possible code violation.
Therefore, also a possible code violation.
Renovation
New Member
http://www.oldhousejournal.com/Chimney_Liners/magazine/1465
Well according to that article you're not suppose to.
"Stainless steel flue liners come in rigid and flexible formats. Rigid flue pipes are available in diameters ranging from 3" to 10", while flexible corrugated metal tube runs from 2" to 10" in diameter. Rigid flue liners shouldn't be confused with double- or triple-wall chimney pipe, which is designed for unenclosed chimneys and shouldn't be used as flue liner. Rigid liners are best only for straight chimneys with no offsets or bends."
But why is it okay to run it inside a wooden chase on the side of your house? (maybe it's not, but I know ive seen it done)
Well according to that article you're not suppose to.
"Stainless steel flue liners come in rigid and flexible formats. Rigid flue pipes are available in diameters ranging from 3" to 10", while flexible corrugated metal tube runs from 2" to 10" in diameter. Rigid flue liners shouldn't be confused with double- or triple-wall chimney pipe, which is designed for unenclosed chimneys and shouldn't be used as flue liner. Rigid liners are best only for straight chimneys with no offsets or bends."
But why is it okay to run it inside a wooden chase on the side of your house? (maybe it's not, but I know ive seen it done)
If the tee and thimble are also free and the pipe easily fits, it may work, with some adaptation and cement.
Renovation
New Member
I would support it of the top of the chimney. I would be connecting the flex coming off the insert directly to the class A. Being connected to the flex would add some support as well.
Something like this
http://www.duravent.com/?page=4a1.php
Something like this
http://www.duravent.com/?page=4a1.php
That stuff can get pretty heavy. Class A chimney is typically supported at the bottom as far as I know. If you support it at the top, it is essentially hanging there. It may want to pull apart.
Yeah it is designed to be supported from the bottom.
I could fab up a bottom support plate with legs that would sit on the smoke shelf, and the flex pipe would come up in between the legs.
I could fab up a bottom support plate with legs that would sit on the smoke shelf, and the flex pipe would come up in between the legs.
Renovation
New Member
kgrant said:
Now you're talking. Once you get the pipe, look up the installation manual and the supports they sell--like on northlineexpress. Not to buy, but to see how the pipe is supported. Then you can mimic that, remembering not to make it out of anything flammable.
I'm still curious to hear if/how/why manufacturers say not in a chimney, since it's enclosed in masonry anyway. The worst I can imagine is stresses of fitting it in the flue cause it to leak at a joint like a cold Morton Thiokol booster, but still, it's inside masonry. That's not so say there isn't a reason, I just can't figure it.
Good luck!
offroadaudio
New Member
I'm trying to find where I read that - so far Excel DOES allow it per the PDF install doc on their web-site.
SteveKG
Minister of Fire
Free Class A is good. Very good. I just bought some to add another chimney to my house, and it shocked me, having not bought any in over a decade.
I also recommend figuring a way to support the stack from the bottom. If nothing else, some sort of steel plate with a hole cut in it. I only know Metalbest [Selkirk], but they offer a small base piece, just a ring-sort of thing into which the bottom section of pipe will screw. You can bolt that little piece down, if wanted. I've never used it, just seen it in catalogues. You could use that to attach the pipe to a steel support plate of some kind. It would last forever. I would also secure the pipe run at the top of the masonry chimney, something simple would work. Particularly if a stove pipe section or even the cap extends out beyond the masonry. You don't want wind rocking that pipe around.
Also, as you lower the pipe into the masonry chimney, make double sure you have tightly secured the locking bands that go on each connection between sections. I have seen one case in which winds moved the stack very slightly, and over time, somehow, one section of this run had come loose. It had unscrewed, in other words. It did not come apart, the upper sections of pipe were too heavy, but it was quite loose and an unusually high wind or storm could have made life interesting. I doubt there would be any trouble with your Class A protected down inside the masonry, but just be sure.
I also recommend figuring a way to support the stack from the bottom. If nothing else, some sort of steel plate with a hole cut in it. I only know Metalbest [Selkirk], but they offer a small base piece, just a ring-sort of thing into which the bottom section of pipe will screw. You can bolt that little piece down, if wanted. I've never used it, just seen it in catalogues. You could use that to attach the pipe to a steel support plate of some kind. It would last forever. I would also secure the pipe run at the top of the masonry chimney, something simple would work. Particularly if a stove pipe section or even the cap extends out beyond the masonry. You don't want wind rocking that pipe around.
Also, as you lower the pipe into the masonry chimney, make double sure you have tightly secured the locking bands that go on each connection between sections. I have seen one case in which winds moved the stack very slightly, and over time, somehow, one section of this run had come loose. It had unscrewed, in other words. It did not come apart, the upper sections of pipe were too heavy, but it was quite loose and an unusually high wind or storm could have made life interesting. I doubt there would be any trouble with your Class A protected down inside the masonry, but just be sure.
Renovation
New Member
snowtime
Minister of Fire
Class A can be supported from the top as mine is. You just have to get the right fitting. Basically its a ring that screws into pipe with support brackets and its rated to have up to 16' below the support if I remember correctly. To be careful I used 2 supports but then I have pipe above and below brackets.
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