I would add that you should wear some really soft bottomed tennis shoes. I have a couple of pairs of cheap tennis shoes that are about worn out but, that have super soft soles. Don't spin your feet as you move around up there. Plant it and pick it up to change the angle. I keep my feet spread apart so as not to direct a lot of weight into a small space. On my old class A I was on the roof a lot. The materials up there should be plenty substantial to hold your weight. I would try to avoid leaning a ladder up against the top corner as well. I use a tall folding ladder and step over onto the roof. The ladder never touches the RV(s). And, be careful. You'll get comfortable being up there and can misstep right off of the thing. I've seen it happen. Almost done that once or twice.
