Question on Roof Cleaning

Hey Guys,
I have a quick question. I have a customer that I have cleaned and sealed his deck for years. However, this year he wanted to know if I would clean his asphalt roof. A fairly simple roof to get up on. Safety is not a big concern. The big question is- what cleaner should I use? The roof has a lot of mildew and dirt cling to it. I have a bottle of nu-again I received a few years ago and remeber being told it can clean asphalt roofs. Is this true? If so, do you thin with water? Any other cleaners? Thanks.

Tom,
I used Nu Again to clean my shingle roof and it worked good. I dont remember what ratio I used but think it was 5 to 1 with water. I sprayed it on and waited about 10 mins,,very lightly scrubbed it with a soft broom, waited about 10 min more and sprayed it off with my garden hose. Worked good, and still looks good after a year or so.
Be careful as the run off might kill your plants near the house.

Roy Moren
Decks and Docks
Odessa Fl