re: DIY Roof Wash

I’ve tried a few things from Home Depot and nothing seemed effective. I scrubbed a small area under a tree shade area with a brush and that helped a little. Too much to do the whole roof though. I know the commercial guys use something that will kill all your plants if they don’t cover them below the roof. My neighbor had this happen. I prefer something I can spray since I don’t want a pile of people stomping around on my roof. Next roof i get, I’ll have the Zinc strips installed at the top to kill the algae.