What's the quickest method to remove black streaks from roof?

There are chemicals sold at your local hardware store that you can attach to the end of your hose and spray on your roof. I don't recall what it is called, but you can ask at the store. We have used it in the past with success. If the black streaks are really bad, you may need to get up on the roof with a push broom and loosen up the grime. Good luck!

Hi Myrtha,

That is very difficult to do. Many people think a pressure washer will work, but the problem is that a pressure washer will erode the pebbles in the roofing so that it will need to be replaced sooner and/or develop leaks. The black streaks are a combination of dirt and mold/mildew or defective shingles. We've had ours cleaned but always from someone who got onto the roof. I'd suggest getting several quotes from professionals if you don't know someone who can safely get on the roof. Wishing you the best.

You'll see immediate results, should you follow Linda's advice.

You can use a garden sprayer and liberally apply Wet n' Forget as an alternative. You may have to ascend a ladder part way, to reach highest points. This method takes months, but is effective. Cover any ground plants nearby, before applying.

Installing a ridge cover of copper or zinc should eradicate the streaks, as well.

Wet n Forget has a hose end sprayer kit now that claims to shoot 30 feet. Might save a trip to the roof.