I cannot find anything on the web that indicates that the flue has to extend
2" beyond the crown.

The chimney has to be 3' beyond the portion of the roof where it emerges.
The chimney also has to be 2' higher than anything that is within 10'.


"DerbyDad03" wrote in message
...
wrote:
On Sep 13, 1:07 pm, DerbyDad03 wrote:
Sheldon wrote:
Why are so many chimneys built with the flue(so) that extend above the
crown?
For Looks?
To improve the chimney draw? I would think the small increase in
height
would make little or no difference
To allow the chimney to meet code? I would think the chimney could
just
have been built at the correct height in the first place.
Sheldon
AFAIK, the code requirement in most areas is that the flue must extend
at least 2" above the crown. YMMV

Picture wind gliding across a sloped crown with no flue extension. You
can almost imagine the wind sort of sealing the flue opening.

Now picture wind gliding across a sloped crown and hitting the wall of a
2" extension. The wind is forced upward instead of flowing across the
opening.- Hide quoted text -

- Show quoted text -

extension helps screw chimney cap on......... try to do it with "
flush flue"

But is that why it's code?