Single Wall Black Pipe...

[aeneas1]

can single wall black pipe be used for indoor installations assuming an 18" clearance from combustibles? i'm considering installing a pizza oven indoors in a location where the run from the top of the oven to the cieling would be about 15 feet. given the steep price of double wall pipe, i thought i might be able to use single wall black pipe for most of the run and double wall pipe through the roof....

any thoughts would be very much appreciated.

[dmun]

Single wall

Once you go inside, you have to go to code, even if you aren't getting a building permit. If, god forbid, you had a fire, your insurance company could disallow your claim if you had single wall flue pipe walled up somewhere. That stuff is only for connecting an appliance, like a wood stove, to an approved chimney in an open room, where it can be examined for corosion or leaks, and be disassembled for cleaning.

I'm a great one for saving money, but this could be a very expensive shortcut.

Building code is not just bureaucracy. It's the distilled and applied experience of hundreds of years of people trying to build fires in wooden buildings.

[CanuckJim]

Single Wall

Please, please don't do that. Everything Dmun says about single wall pipe is true. My wood stove in the kitchen has single wall pipe up to within 8 inches of the ceiling, where the double wall takes over, for exactly the reasons he outlines. However, enclosing it for such a long run invites disaster. Some years ago, I was involved in a research project that required reading more than a few 19th century letters and newspaper reports. The litany of remorse about chimney fires was endless. Sometimes, only an isolated house went up, sometimes a city block, sometimes an entire wood frame town. These people heated with wood, and, mostly, they knew what they were doing, but they only had single wall to build with. You don't. Go for the double wall. I'd like you to be around for a few more years to contribute to this forum.

Jim

[maver]

He might be asking if he can set it up like yours is, Jim. Unfortunately, he talks about ceiling (inside cover for the room) and roof (outside cover for the house) both and is not clear which he means. But it sounds like code would allow single wall up to a certain distance from the ceiling, then double wall through the ceiling and up through the roof? If he has a 15' ceiling he's probably ok?

[aeneas1]

Once you go inside, you have to go to code, even if you aren't getting a building permit.

actually you have to observe all codes whether the planned installation is inside or outside - and what i suggested, single wall black pipe 18" from combustible material, is to code for interior installations. if i decide to go forward with this project i would install a "free standing" igloo type oven as opposed to an oven that was mounted, recessed or enclosed into an existing or new structure - because of this a building permit would not be required, only a mechanical permit.

God forbid, you had a fire, your insurance company could disallow your claim if you had single wall flue pipe walled up somewhere.

i'm not sure what you mean by "walled up somewhere" - my plan is to have the pipe exposed throughout the run with a clearance of at least 8 feet (even though code requires just an 18" clearance) from the nearest combustible material. i would use double wall near the oven and i would also use double wall through the roof along with approved support box, anchor and cap.

My wood stove in the kitchen has single wall pipe up to within 8 inches of the ceiling, where the double wall takes over, for exactly the reasons he outlines.

this is exactly what i am proposing.

However, enclosing it for such a long run invites disaster.

again, i never said anything about enclosing the pipe

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so what do you think? is single wall a bad idea given what my plan would? also, i very much apprecaited your quick and informative responses - this is an absolutely wonderful forum.

[CanuckJim]

Single Wall

Sorry for that; I was a bit confused. If the single wall is exposed and such a great distance from combustible material, you should be just fine. I got the impression it would be boxed in somehow, and I was worried that if you couldn't see it you couldn' monitor it. Sounds fine. Try to get the thickest gauge pipe you can.

Jim

[aeneas1]

He might be asking if he can set it up like yours is, Jim. Unfortunately, he talks about ceiling (inside cover for the room) and roof (outside cover for the house) both and is not clear which he means. But it sounds like code would allow single wall up to a certain distance from the ceiling, then double wall through the ceiling and up through the roof? If he has a 15' ceiling he's probably ok?

exactly my sitch - distance from top of oven to cieling would be about 20 feet. i thought i would use a 3' section of double wall at the oven and enough double wall through the roof (which is about 1' thick) which would satify clearance requirements on the inside of the building (cieling) and outside of the building (roof). that would leave a distance of about 15' (from the top of the double wall pipe at the oven and the bottom of the double wall pipe at the cieling) which i would fill with single wall black pipe.

btw it's my understanding that single wall pipe wil get very, very hot in this application - if so, how hot do you think we are talking? i ask because i'm thinking that i might be able to make great use of this heat as the oven would be in a large, open room that is generally very cool throughout the year and even more cool during the winter. i thought i could use fans to circulate the heat the pipe gives off and junk my propane space heaters.

Sorry for that; I was a bit confused. If the single wall is exposed and such a great distance from combustible material, you should be just fine. I got the impression it would be boxed in somehow, and I was worried that if you couldn't see it you couldn' monitor it. Sounds fine. Try to get the thickest gauge pipe you can.

no apologies necessary jim! obviously i wasn't very clear! the reason i started this thread is because i did not see any mention in this forum of single wall black pipe being used nor did i see it for sale on any of the wood fire oven sites. but it appears that my situation is unique and that most oven installatiions would not have runs as long as mine...

[CanuckJim]

Single Wall & Heat

I can only talk about the single wall pipe on my indoor wood stove. Obviously, it's hottest right at the junction with the stove proper, and my exposed run is quite short, about five feet. You would avoid this by using double wall at the exit from the oven. The pipe is noticeably cooler where it enters the double wall, even after that short a run. The pipe gets quite hot, too hot to touch, but it never gets so hot it glows. Then again, I do not stoke it so much that flame shoots up the pipe. It would radiate considerable heat into your large room, and I'd go for the fans.

One consideration: creosote participates out of smoke as it cools. With such a long run, you might, maybe, perhaps, have to be on the lookout for creosote deposits in the single wall pipe. This, of course, is the major reason for chimney fires. I would definitely try for a straight run to the ceiling, without elbows if at all possible, because this is where creosote, if any, will build up. I'd install a flue gas temp gauge in the pipe, so you could monitor how hot the gasses get.

I doubt creosote would be an issue with oven temps, but try to burn well seasoned wood, and try to avoid resinous woods like red pine.

Sound like fun.

Jim