This is a rough cross section side view of the front of my house. It's amazing the crappy drawings one can make with MSPaint. :-)
That small section of roof has no attic type access. There is no way for us to get in there at all. I took the fan out but there's a metal bracket which i think i'd have to rip right out of the drywall if i wanted to get a better view up there. I didn't do that. And there are no other vents of any sort in that small section of roof.
Questions: Is this venting of a powder room directly into the soffit a problem or a regular practice? Since there's no shower or bathtub to produce excess moisture, maybe it's not a problem.
Why did the builder put a flappy vent right above the fan and never use it? My assumption was that they meant to connect the fan to the vent and forgot, but my builder is respectable and so seemed the repair guy. I don't automatically assume he's giving me a line to avoid doing work.
The only other thing it could be is just a way for that small roof area to breathe to the outside air. But if that was the case i would have expected just a roof air vent like the ones that are up on the attic roof (not in my picture).
Kevin