I must have a small roof leak in my 1.5 story, 2 dormer, roof.
There is a small darkening spot, about 6" in diameter, on our 1st level bathroom. It's about right at the point where the 1.5 story dormer meets the roofline. From that bedroom I looked out onto the roof and see the shingles as they come up to the roof nailed at the very top where the roof meets the dormer. The top row of shingles are nailed and the nails are exposed. One nail in particular seems to have broken through the shingle. I'm thinking I need to start there and somehow seal that nail. How should I do that?
What else do I need to look for? How should the roof shingles as they meet the dormer walls be installed? It just seems like that is a leak waiting to happen with a wall running down to a roof where it cannot be properly capped. Is there some sort of flashing there?