"Speedy Jim" wrote in message
...
G wrote:
SNIP

Since it doesn't seem to drip/leak when I use my plumbing fixtures, I'm
going to assume that the leak starts somewhere ABOVE all the joint areas
and hopefully a nice long-term remedy will be that 180 deg "Return Bend"
as you suggest. I guess the worst thing is that I'll have a tiny bit of
air escaping from the vent pipe into the house, but I assume it won't be
enough to cause problems with smells & things like that.....

Sound about right on all this?

Yep~!

As long as when you run the water into the vent from the roof and most of
the water goes to the drain, you are ok, if the vent is filling up then
overflowing from the hole into the house, you have a seperate problem and
need to clear that clog as well.

If it does drain, the leak is probably at a bend where the pipe runs nearly
vertical for short distance.