What is the right way to remove moss on composition roofing?

[Guest]

What is the right way to remove moss on composition roofing?

[Dana]

I haven't tested it, but I've read that a strip of copper or zinc flashing peeking out from an upper course of shingles has sufficient toxicity to kill & prevent moss from growing down-slope of the exposed copper.

I'm sure it would take some time if the moss was well-established. You can kill the moss by spraying concentrated bleach on it, then hose it off weeks later when it's dried up & crumbling.

[Dana]

Make that copper flashing, not zinc, and skip the bleach (unless you're very careful about it). see:

http://counties.cce.cornell.edu/oneida/home%20garden/fungus%20&%20moss/Moss%20on%20Roof.pdf