re-coating roof

I use an all-purpose cleaner and a scrub brush.

I was given CamCo roof cleaner available at Walmart. It sat on the shelf for a long time, but then I went to clean the roof and didn't have my usual Spic & Span so I used it. Was not enthused while cleaning, but the rinse water was brownish. But when it dried, boy what a difference - very white and bright. Here is a picture I used for selling it taken after cleaning it and laying down caulk.

Moderator edit to re-size picture to forum recommended limit of 640px maximum width.

Thanks 2012coleman Ill try that