Why is my skylight leaking?
Condensation can form on more than just glass. In some cases, the installer neglects to use roofing felt and insulation between the frame of the unit and the rough opening. This allows warm, moist air to escapefrom the room and come into contact with the underside of the flashing and/or cladding. The resulting condensation will drip back into the room between the frame and rough opening, giving the appearance of a leak.
Having the roofer or installer add felt and insulation between the frame and rough opening should prevent this problem.