What's the best way to kill moss on the roof?

50/50 nleach is correct also metal strips will stop futher growth if you do not like the look you can buy cap shingles that are imprehnated with zinc, to match your roof alot more work ,but if your roof has alot of years left much more cosmetically appealing, one brand of shingles that sells this type of roof cap is "Elk"  more

The attached article explains how to control moss growth on your roof. Good luck!  more

Bleach works good to start of with. After that go to Home Depot & get some bars that go across your roof. When it rains they give off a solution that stops mold.  more

Clean the moss off the roof and then spray the roof with a 50/50 mixture of bleach and water. Let it stand about 15 min and rinse.  more