We also noticed during numerous rainstorms prior to repairing the roof that the current gutters did not hold the rain in the gutters but allowed the water to cascade over the edge. When we looked at doing this work, we had the option of doing it ourselves or hiring a contractor to do the work. After looking at the logistics of stripping off the old roof, making what we assumed were extensive repairs, making the section waterproof, and then doing the roofing on a large curved section, we realized this was more than we could do by ourselves. The three most challenging parts of the reroofing were the flat section by the door, the two curved sections, and rebuilding the built-in gutter. We decided to hire a contractor to do the work.
Flat roofs do have unique problems, and the section of our porch roof that is flat is no exception.
Our section is also a balcony that is open from the master bedroom. So not only is it flat, but it doubles as a walked on space. Our contractor recommended a rubber membrane roof using the thickest material. The pitched roof section had a gable, and more problematic, curves on both ends of the porch. We had seen several ways of handling these round sections and we knew we did not want some of them.