I noticed a water bubble on my bedroom ceiling, so I went in the attic
to investigate. It turns out a pipe that vents to the roof had become
disconnected at the first joint, so I just re-connected it. I assume
when it rained hard enough, rain water was leaking down the pipe and
on to the ceiling (we just had a hard rain).

But that got me thinking.. Even if the pipe didn't become
disconnected, should rain water still be leaking down the pipe?

Thanks,
Dan