Streaks on Roof
Went topside to do some cleaning of leaves and pine needles and notice several black stripes across the roof. Looks like mildew. There is a slight ridge there, and they are 4' apart, so I guess they are at the seams of the sheathing.
Anything I should be concerned about?
We boondock with no utilities, so I can't wash the roof, but I could wash the stripes if necessary.