I received the following question:
I had a metal roof installed over existing shingles two years ago. I have continued to have a laeking problem on my carport 10-15 feet below an old sky light. I had it re-flashed but still have some leaking below. I suspect water above the skylight somehow permeates and gets under the roof and leaks below on the carport. The installer blames it on the need for a new skylight. Any ideas?
Probably about 30% of all problems I see with skylight leaks are indeed related to the skylight itself. Probably about 30% are related to a problem higher up on the roof such as at the ridge, a pitch change, or a pipe where water is getting under the panels and running down on top of the underlayment until it hits the skylight and then enters. The remaining 40% are due to improper flashing of the skylight.
Send me pictures of your skylight and roof if you like for further input. You can email me at firstname.lastname@example.org