In preparation for the roofers to come, I set about cleaning the moss off the roof before the install the standing seam, and let me tell, that stuff is not easy to remove. The roofers told me that it was a good idea to clean off the excess moss, otherwise they would do the rest.
Figuring it would be a piece of cake, I took out the ladder and got up there, and ended up spending hours in the hot sun trying to get that stuff off.
I later learned that when the stuff is dry, it cakes on like rubber cement and requires a fair degree of effort to scrape it off. Everyone says it'll come right off with a push broom, but I ended up using a pry bar to scrape it off. Factor in the fact that it is amazingly prolific, and it's a tough job that is nearly impossible to clean thoroughly.
What is really a drag is that unless you get every little bit off, the darn stuff returns with a vengeance at the first sign of cool moisture, i.e. the next morning. I couldn't believe it.
I noticed that when the stuff is moist and plumped up from the rain, it is much easier to scrape off, so that's good to know for the next roof I need to clean, which may be never. Also, I had to remove some fairly well established wasp's nests to work up there, which always makes the job more fun and interesting, especially on top of a roof.
Then again, a real man wouldn't complain about these things, so neither will I.
Until the next time, thanks for reading.
PS I was told later by the roofers that the moss will simply die beneath the metal roof, so I didn't need to fret over removing it, though stressing over life's details is like breathing for me.