Stack extension

[fourustircom]

Hi!

Anyone know if I can use single wall vent pipe above the roof line? I've got the double wall stuff extending out of the shed about a foot, but feel like the stack is too short even with the rain cap I installed. 8" fuenace pipe fits pretty well over the double wall pipe.

Thanks!

 

[leon]

double wall to single wall pipe.

Hi!

Anyone know if I can use single wall vent pipe above the roof line? I've got the double wall stuff extending out of the shed about a foot, but feel like the stack is too short even with the rain cap I installed. 8" fuenace pipe fits pretty well over the double wall pipe.

Thanks!

I would be more worried about the stack temperature cooling to quickly and developing a lot of creosote, and the single wall pipe may not fit properly/flex too much due to the inner and outer walls of the double wall pipe.

I have a 8 by 12 block chimney with natural draft that is tile lined and I had a rain cap on it to reduce down drafts and rain etc. and the cap was plugged with creosote so I pulled it. I am usure if I will try to use it again.

I had a vacu-stack on it years ago but its size allowed blackbirds in it so I removed it too.


I don't honestly know but a reputable stove dealer would know as the diameters of the pipes may not slide together.


leon

 

[fourustircom]

Thanks for the reply. I'm not as worried about the creosote since I'm burning mostly hardwood and have a great chimney brush. I, too, have a rain cap, so I'll keep an eye on that.

 

[fourustircom]

Also, the double wall stuff is pretty pricy just to see if it solves my smoke problem.

 

[avalancher]

Just to try it to see if it helps your problem,sure. But I wouldnt leave it there as a long term solution. Unless you can find some single wall pipe that is stainless, it wont last long. Being exposed to the elements on top of conducting a lot of heat through it will cause it to rust out really quick. Think of a burn barrel. How long does it last? Not long. It will rust out quick.
I might try a single wall just to see if it helps, but I wouldnt leave it up there more than the time it takes to run through your experiment.
If you are having a down draft problem, look at your roof line. If your pipe does not extend about the roof peak, that could result in a downdraft situation, as well as just a poor draw even when the pipe is hot.

 

[clawmute]

Mine extends up from below the eave line to a couple of feet higher than the ridge. I have it guyed off so wind doesn't take it down. Where it comes through the wall is triple wall pipe and the vertical is supported by a bracket I made and screwed to the outside wall. where it turns vertical I have a tee there with the down branch capped for clean out. Works great. 6" galv. stove pipe w/galv. rain cap.

 

[kevin j]

Long term, I'd second the concerns on temperature. condensation, even icing up on top (had it happen), and poor drafting if the top is single wall and cold.

I would also try the experiement, then go with double wall if the experiment is successful. Maybe find some craigs list double wall if the cost is a show stopper to buy new.

k

 

[Blowncrewcab]

Rule of thumb is, the stack has to be 2' higher than any roof within 10'. that way you'll eliminate the waterfall effect of the wind coming over a ridge and slowing the draft.