My masonry chimney has a flue for fireplace and also for oil stove. Do I need to do anything special, or be concerned with top of chimney(for the two openings) when I install the liner and cap?
2 flues 1 chimney question
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A common practice is to stagger the heights. Meaning the liner and cap should extend 9" higher than the adjacent flue
My set-up is with 2 Class A chimneys next to eachother, so it's a little different than yours, but I set mine up with the chimney that gets hit with the prevailing wind first higher than the other and it has not caused any downdraft issue for me.
elkimmeg said:
just so i know , which would you set higher , the wood or the oil, id think the wood one , but i dunno for certain, hence, im asking
good question I would set the wood higher Why? the wood employs a constant draft where the central burner is intermitten.
Ever more so if the wood stove carries more of the heating load
Ever more so if the wood stove carries more of the heating load
elkimmeg said:
I've asked this before, not gotten a real clear answer - How does staggering the heights of a multi-flue chimney mix with the 2-3-10 rule? Seems like if you are staggering, then the lower flue is in violation? Also how mandatory is it? My chimney has two flues, at approximately the same height, covered by a single common cap - is this an issue?
Gooserider
Goose long story for short answer/. These people buy their home a year go last sept. They had a chimney sweep come out and clean the chimney and recomended a single cap installation $250 and installs it
( masonry flue chimney home built in 1996)
New years day they have a get together and fire up the fireplace, The day was cool damp drizzle . Things went well and as the fire smolder going out they went to bed The wife remembers she has a load of laundry in the washer that needs to be placed in the dryer sh opens the cellar door and the entire cellar and play room is filled with smoke
for some reason the smoke alarm did not sound they call the fire dept and while blowing it out with fans the smoke was commoing out the sah cleanout doors the the burner vent pipe
Why that cap that services both flues acted as a block trapped smoke in since the burner was not comming on it down drafted the burner chimney the ash cleanoi=ut was not separated but
two doors in a common area. the cause yes the weather no air movement heavy cool air and the Cap had the cap not have been installed the smoke would have continud its spiral path upward
and probably not have been down drafted in the adjacent flue and if it did it would have never been that consentration..
I not a fan of the common chimney cap I have never had a cap for my masonry chimneys
( masonry flue chimney home built in 1996)
New years day they have a get together and fire up the fireplace, The day was cool damp drizzle . Things went well and as the fire smolder going out they went to bed The wife remembers she has a load of laundry in the washer that needs to be placed in the dryer sh opens the cellar door and the entire cellar and play room is filled with smoke
for some reason the smoke alarm did not sound they call the fire dept and while blowing it out with fans the smoke was commoing out the sah cleanout doors the the burner vent pipe
Why that cap that services both flues acted as a block trapped smoke in since the burner was not comming on it down drafted the burner chimney the ash cleanoi=ut was not separated but
two doors in a common area. the cause yes the weather no air movement heavy cool air and the Cap had the cap not have been installed the smoke would have continud its spiral path upward
and probably not have been down drafted in the adjacent flue and if it did it would have never been that consentration..
I not a fan of the common chimney cap I have never had a cap for my masonry chimneys
Well having had a duck come down the chimney and trash our summer cottage one winter, I am a big believer in having some sort of cap on all chimneys.
The problem we had with our old setup was that the roofs on the two seperate caps overlapped so that rain falling on the roof of the upper cap would run onto the roof of the lower cap, which would dump it down the flue of the upper cap. I don't think it was a big volume, but still that didn't seem like a good thing.
Now we have the shared cap, and don't appear to be having a problem as yet with downdrafting.
If we do is there a solution, like possibly putting a divider in the cap?
Gooserider
The problem we had with our old setup was that the roofs on the two seperate caps overlapped so that rain falling on the roof of the upper cap would run onto the roof of the lower cap, which would dump it down the flue of the upper cap. I don't think it was a big volume, but still that didn't seem like a good thing.
Now we have the shared cap, and don't appear to be having a problem as yet with downdrafting.
If we do is there a solution, like possibly putting a divider in the cap?
Gooserider
Goose, That is the exact same thing that happened to me. Water from one running off into the other, but I guess a little water is better than no cap? Elk, is your stove getting water in it?? when it rains in the summer doesnt water get into your stoves? Or is there just a cap on your stove and not your furnace flue. I'm preparing to install a multiflue cap this spring. I just hate the thought of water in my masonry chimney.
Metal said:
This is why I'm confused... :-S The manuals I've seen say (in part) that "the chimney must be at least 2 feet higher than any part of the building within 10 feet" - now unless you have a really HUGE, BIG chimney, then if one flue is sticking up higher than the other, then the lower one is not "2 feet higher than any other part of the building within 10 feet" unless they don't cound the other flue as being part of the building....
It seems like it would put you in the position of one of those "Mine is bigger" competitions you sometimes see in cartoons...
Or are they only talking about the overall chimney structure, and not worrying about the individual flues within that chimney?
Gooserider
I understand the 2 and the 10, so what is the 3 of the 2-3-10 rule. I did a search on this rule and still didn't quite understand the explanation.
the 2/3/10 rule is the chimney extention must extend 3 feet above the roof 2' higher than any other structure within 10 feet.
Note 3' above the roof not 2' but 3'
Note 3' above the roof not 2' but 3'
bcnu said:
There are two basic scenarios possible when a chimney sticks out of a roof...
1. The chimney comes out right at the peak of the roof, or out of a flat roof - In that case the distance from the peak to the top of the chimney must be at least three feet.
2. The chimney comes out somewheres in the middle of a slanted roof - The chimney top must be 3 feet above the highest point where it comes through the roof, plus if you draw a 10' radius circle around the chimney, it must be at least two feet taller than anything inside the circle.
In other words, there are two different tests, and you need to pass BOTH of them. In the case of our house, the chimney comes out of the middle of a very steeply pitched roof, so in order to get past the two feet higher test, our chimney is over SEVEN FEET above the point where it comes out of the roof. Our neighboor has a chimney that comes out the peak of their roof - since it is the peak, there isn't anything within 10 feet that they have to worry about, so they just have to be three feet above the peak.
Gooserider
Thanks guys. I understand your explanations. I think my chimney meets the rule and will double check before I put in the liner.
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