Leaking "Dry" Stack Vent

You wouldn't normally think of this plumbing issue, but theres a reason why vents need slope. If this vent had been plumbed through the roof with this backwards slope, it is foreseeable that it could fill up completely and occlude the vent.

[@LuminairPrime]

Good example of a building code rule that smart people think they don't need to follow... and even with that vent sloping properly, the humid air will still condense inside the roof and grow mold over the decades. Ask me how I know! Vents need to be vented outdoors.

[@MyFortressConstruction]

Yeah, you're right. Especially in an attic that doesn't move a lot of air. Vent it outside!