I just thought I'd blab my tale of woe.
A number of years ago, I had my roof replaced along with the skylights (of course). The previous ones were those square acrylic bubble types, the new ones, rectangular and glass.
This left framing work to be done on the inside. Called a guy, he took care of it, sheetrocked it, thanks.
(sigh) New skylights, one of them has a leak. Can't pinpoint it for anything, and there is no rhyme or reason when it would leak. Frustrating, to say the least.
Finally called this guy who advertises No More Leaks, I think that's the name of his company. Older German/Polish? guy he got up there with some expensive roof stuff (I read about it somewhere, it's not really available to the public and it's hundreds of dollars a roll if you could get it. I digress.)
The source of my leak? The framing guy had nailed up through the flashing. Thanks a lot. How annoying is that.
nancy