Q - Our roof has dark streaks in various places even though there are no trees directly around our home; our neighbor says it needs to be cleaned. How would we clean the roof?
A - Your neighbor says it needs to be cleaned? Your neighbor?
The guy with his Christmas lights still out on the house. The guy whose trash can sits at the curb for two days after the trash is collected. The guy whose house hasn't seen the business end of a paint brush since the Clinton administration.
That neighbor says you should clean your roof?
Do you always do everything your neighbor says?
Tell your neighbor to mind his own business.
Now then, if you want to clean your shingles because you are suspecting that it may be time, know this - never use high pressure water on an asphalt shingle roof as doing so will blow granules off the shingles and lessen the longevity of your roof.
The best way to clean them is by getting on the roof (be careful, roof walking is a recipe for disaster - especially when it gets wet) with a garden spritzer filled with a 3 to 1 bleach to water mixture.
Spritz the mixture on the roof and allow it to sit for, well, for a while. Then rinse it off with your garden hose. You may notice the mixture changing color - that is a good thing, as it cleans off the mold and mildew.
When you rinse it off, the bleach will go down the gutter and the downspout, so if you have tender vittles at the end of the spout you will need to protect them from the bleach.
Enjoy your clean roof. If you really want the last laugh on your neighbor, hook your hose up to their outdoor spigot for the rinse job.
It's the least they can do.