Just to explain further, a double walled duct combines intake and exhaust in
one pipe. If the inner wall cracks, the idea is that the flame will go out
as a safety measure. If it is a single wall duct then unless you enjoy
carbon monoxide poisoning, replace it.


"PipeDown" wrote in message
.net...
Is the Flue double walled. A crack in the outer wall but not the inner
may not expose you to fumes.

I wouldn't consider metal tape to be perminant but might use it until the
contractor can get to you. Though they may stand up to HVAC ducts, an
exhaust flue can get very hot and I don't know of any tape adhesive that
will last long like that.



"Robert11" wrote in message
...
Hello:

Just found a crack/tear in the 3" diameter round sheet metal duct that
funnels the exhaust from a gas fired water heater (the typical
cylindrical type) to the main duct going to the chimney.
Probably about 1 to 2 inches in length.

Looks like it is a big job to replace the duct.

Was wondering -

Is it code permissible to place a conforming metal patch, perhaps held on
with two pop-rivets,
over the cdrack ?

That sure seems to me like a simple approach, but before I get a
contractor in I wanted to ask here. If a good idea, and code allowable,
should some kind of "gunk" be placed under the metal patch also ?

How about that metal duct tape ? It certainly would seal it, but could
this be considered a "permanent" fix ?

Any other suggestions would be most appreciated.

Thanks,
B.