Expert: Bart Ogden - 9/12/2009

Question
I'm doing preliminary design work in an CAD program before later paying the big bucks to my architect to finalize the design. I am looking at "stacking" my fireplaces from the basement to the 1st, 2nd and attic floor (4 total) to minimize construction costs and to only have one chimney if possible.

I have seen 3 flues in a single chimney before, but is there a limit?  Is there configuration issues related to cross winds that need to be considered?  I don't want to put this much energy into my CAD drawing if my chimney design isn't even feasible.

On a separate, but related note, the house has a belvedere with a cupola on top that is above the center of the roof.  In order to be code compliant on the minimum distances, I'm going to have to have a fairly tall chimney.  To break up the "visual mass" I am considering using chimney pots.  Does the height of the chimney pot count into the minimum height requirement for a chimney?  I'm hoping the answer is "yes," because it will sure make the house look better!

And lastly, with the chimney on the windward side of the cupola and belvedere, should I have any concerns about the impact of the exhaust?  Anytime we are using the fireplace, the cupola and belvedere windows should be closed.  The upper most windows will be opened to function as a "solar chimney" for passive cooling in the warm weather months.

I appreciate your help!

Answer
Hi Grant,

There is no limit to the number of flues that can share a chimney.  Adjacent Flue terminations should have at least 4.5" difference in height.

The height of the chimney pot is the height of the finished termination.

I have no opinion on the impact of the exhaust.  However, if you meet or exceed the draft rule which requires the termination to be at least 2' about anything within 10', you will likely have no issues.

Thanks for using AllExperts.Com and good luck with your project.

Sincerely,
A. Bart Ogden, President
Home Safe Hearth & Chimney, Inc.
Wichita, KS
Voice 316-265-9828
Fax 316-265-9890
www.HomeSafeKS.com

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