Roof Looks Like a Zebra - Bleach or Roof Cleaner?

Yeah, good call on wetting the plants - seen a few flower beds bite the dust from bleach runoff myself. About the shingles, I've heard mixed stuff too. My mentor swears bleach is fine if diluted properly, but I've also seen roofs that seem brittle after repeated treatments. Makes me wonder if it's more about concentration or frequency? As for specialized cleaners, we used one last summer and honestly...the streaks seemed to stay away longer compared to bleach. Could've just been luck though.