"aemeijers" wrote in message
...
Situation- only thing left in original chimney stack is the vent for the
gas water heater. (Furnace goes out side wall just above ground level
now.) Chimney stack and flashing above roofline is failing, and may be
slightly leaking, judging by stains on bathroom ceiling right below it. I
have been quoted $800 to demo and rebuild chimney stack from roofline up,
using proper flashing instead of sheet goods and tar and gravel like
roofing company used. My father, the 83 YO house designer, suggested that
I should simply demo top part of chimney, patch roof deck and shingles,
and use a prefab metal exhaust pipe instead. How tall would it have to be?
Wind and snow load is a consideration. 5-12 roof, and current chimney is
higher than ridge line of roof. I'm concerned that a real tall metal stack
would look funny and unacceptable to any future buyers and house
inspectors.

Thoughts and ideas?

--
aem sends...

You probably have to maintain the height to be in compliance. I forget the
exact working, but it must be x higher than anything within 10 feet. I'd
consider removing the chimney completely and getting a new high efficiency
water heater with an outside vent rather than a chimney. Total cost may be
similar and no headaches later.