I like blogging about more sustainable home designs, new appliances with high Energy Star ratings and ways to save on your utility bills, including solar panels pointing south on your roof. Think GREEN!
I happened to drive by this house in Fairfax County the other day and was aghast at the amount of moss growing on its roof. I'm posting here to illustrate what can happen if you don't keep your roof clean, especially if it doesn't receive a lot of direct sun light. You don't want to be this 'green' on your roof!
To keep your roof clean under similar conditions, simply wash it with equal parts water and bleach once a year. If you have any shrubs and showers next to the home where that water and bleach will drain, be sure to thoroughly drench them to minimize the harm it could do.
For this home, which has been exposed to a lot of rain this spring and early summer (haven't we all !), I would hire a handyman to get up there an scrape it off with a strong brush and then wash any residue away here too with equal parts water and bleach. DON'T power-wash it because that could hurt the shingles.
To prevent moss and the algae the preceeds it off your roof, insert 6-inch-wide strips of zinc or copper under the row of shingles closest to the roof's peak. Leave an in or two of the lower edge expose to the air. This way, when it rains some of the metal moelcules can wash down the roof and kill any algae trying to get a foothold.