My efforts using search did not yield any useful information. I have an existing metal roof. I added a bathroom and need to run the exhaust fan through the metal roof. To make a long story short, the interior ceilings are all cathedral so there is no attic adjacent to the eaves, etc. My thought is to drill a hole through the roof, cut it to the appropriate size for the exhaust outlet and then install a roof vent on the outside. My concern is how to do this without creating a leak. Most applications talk about installing shingles over the flashing. That doesn't apply, of course, with a metal roof. Can someone direct me to a product or instructions for this application? Thanks.