The roof vent/skylight worked great for the four years it was installed. It was in the ceiling of an interior bath and it provided light and natural ventilation. The ceiling was masonry, about 9″ thick. No problems with leaking. Last year we did have to remove it because we added a second floor to the clinic. It was not needed in the new roof, so we didn’t reinstall it. It was a great product, perfect for the application.