ok i have plenty of 20ft 6-7-8-10″ round steel pipe most with 1/4″ wall
i have a factory fireplace steel with firebrick liner… requires the double wall 8″ flue pipe… i just think i’d be more comfortable with 1 pc vs have’n the joints… and 1/4″ thick vs 20ga or less… i can make mine double wall… 1/4″ pipe inside with a sheet metal surround with the proper air gap ect…
would all my issues be code ones or is there some reason mine would worse than the factory sections?
p
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Beats me, but it is an interesting question.
How would you stabilize the two pipes in relationship to each other?
Need to ensure air flow between the two pipes, openings in the outer pipe at the bottom are a must.
I don't see why it wouldn't work , but code will be an issue as most codes require a certified assembly that has been tested and carries a approval with it.
An extension type spring coiled around the inner pipe would work. One every few feet.Spheramid Enterprises Architectural Woodworks
"Success is not spontaneous combustion, you have to set yourself on Fire"
Good idea!
They can't get your Goat if you don't tell them where it is hidden.
simple sheet metal rings with holes cut for a friction fit... or i could tack weld spacers on the inner pipe so that the outter pipe would "float and always have a min space between then as set by the spacers...
the UL thing kinda has me... who puts the UL stamp on a site built masonary unit?
what if i wanted to weld say... 1.5" pipes in a ring around the main pipe so that i could capture the heat and redestribute it?
i'm not sure how it'd go with an inspector... but then i've never seen an inspector as for much on a site built masonary unit?
p
I know that site built fireplaces here do have to be inspected and the chimney must meet our codes for liner, reinforcement, flue size etc. As for the actual masonry units like the prefabs I would bet they have UL certification on the plans and supplied parts. UL certification is gotten by passing a set of tests. Not sure who lays out the procedures or standards but I think it is AASTM. UL labs are around you would have to start searching for them. http://www.ul.com/info/standard.htm I worked for a while with a wood fireplace place manufacturer ( metal , prefab unit) he actually created his own testing lab , got the lab certified by hiring certified testers and then essentially ran his own test to the necessary standards pass his own fireplace. To pass the tests he had to fire the unit with a specific type of man made log (like a Presto log)and put that info in his test results.Test results and procedures were referred to in his literature but not spelled out clearly. He couldn't get it passed any other way . I wondered how many people are going to keep using just that type of log over the life of the unit?
They can't get your Goat if you don't tell them where it is hidden.
Someone else mentioned that what most call double wall meta chimney is actually 3 pieces . They were correct . Something to think about , I don't remember who posted the info but they were factual in what they were stating IIRC.
They can't get your Goat if you don't tell them where it is hidden.
There isn't a "UL approval" on the site built masonry fireplace, but there are standards governing the size of the firebox, smoke chamber and the size of the chimney... in addition to firebox and chimney construction details.
Things like combustion air are also addressed by building codes.
Ash pit doors, log lighters and flue damper assemblies are also UL approved or constructed to meet approved standards.
Masory fireplaces are inspected here.
I'd go for it myself.
Bear in mind its gonna be heavy to support and not UL listed as such..so a fire might leave ya with pants down for Ins. Co. to have at ya.
Even if the fire is in no way related to the flue. They'll find a way to weasel out. And if a tenent should die..well...your call.
Spheramid Enterprises Architectural Woodworks
"Success is not spontaneous combustion, you have to set yourself on Fire"
i have a factory fireplace steel with firebrick liner... requires the double wall 8" flue pipe...
Double wall or triple wall? Some (if not all ) of those factory builts use the two outside chambers of the chimney as an intake and on outlet to cool the box to reduce the clearances as well as keep the flue warm. 1/4" steel pipe has more mass and consequently will take longer to heat up, creating more creosote. Also, the actual flue pipe is stainless steel in the factory built chimney. Corrosion will be fairly rapid inside the steel pipe. I see your reasoning, but the chimney does more than just remove the smoke in these things. It certainly won't meet the UL listing which would be a problem if something goes wrong.
http://grantlogan.net/
Today we's learnin' about rawks. They's all kinds of rawks. These [picks up rock] is rawks which you throw. These here [throws rock at Rusty] is rawks that you get hit with. E.Cuyler
I've 6" cast iron water pipe on the woodstove in one of the barns. Works great, but using it as just single wall.
Only problem years ago when first fired it up was the popping sounds as the cement lining heated and cracked off <G>
don't do it, follow manufacturers instructions = insurance, building code, mortgage, wife, kids, dog, fish .... if it's a gas unit, the rust build up will be huge, if it's wood burning the extra steel will transmit and hold even more heat, don't do it!
Even though it may function as a chimney, your home made solution *does not* have a UL listing. That will be a problem for you should anything ever happen.
Given the diameter required, I suspect your manufactured fireplace is a woodburner. Factory made chimney assemblies for this have a stainless steel inner liner... and a UL listing.
The joint laps are designed to go with the flow of flue gases. It is also damn near impossible to get the sections of pipe apart without destroying either the joint or the locking mechanisim once they have been snapped together properly.
Your Sch 40/80 pipe is also quite heavy and would need significant support so the fireplace did not collapse.