I'm surprised that, after living in wet and rainy Seattle for so many years, we've never had a problem with roof moss before. I recently started noticing that a portion of our roof was getting a little green, even though it was in an exposed area that gets lots of daylight and no shade. Well, our roof is about 10 years old, so I guess it's time for the embedded shingle chemicals to stop doing their moss fighting duty.
So, what's a green homeowner to do about the green? Well, the classic method of treating moss and algae, whether on roofs or sidewalks, is good old-fashioned bleach. But, this is an environmental quandary since bleach presents all sorts of problems in general and, when used outside, causes even more issues specifically dealing with runoff into storm water drains and groundwater.
I've read that 1/4 vinegar to 3/4 water solution will kill the algae. Has anyone had any success with this or does it just come right back? Or is some sort of allegedly eco-friendly commercial product the way to go?
What about oxygen bleach? Is that just as harmful as chlorine bleach? What about zinc sulfate or zinc/copper strips installed on the roof line? Or do I need to just scrub the bejeezus out of the shingles?
Do any of you have any suggestions for an eco-friendly method of removing roof moss that someone can easily do themselves? Or is it just better to hire someone with the chemicals, the skills and a roof pressure washer to take care of business?
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