Had the pleasure of having Alberto Rivera in from Tarpon Springs Fl today and tomorrow attending my school. Here is a job we did today. The owner is a member of our church and we did this for free to help them out. The roof really needs replaced but they cant afford it so we are hoping we can get some more life out of it for them. I included pics of some of the shingles showing the grit loss and the gutters with grit in them. Someone actually PRESSURE WASHED this roof a few years back and now the roof is paying for it. I think the grit loss pics will be great for showing what the gloeo and using pressure can do to a roof.
The spraying of the bottom 3-4 shingles first really helps to control run off and slow it down. I started doing this back in the 80's in Florida when I use to downstream my chemical on a roof and then rinse with a soap tip. Very Archaic method to clean a roof by todays standard but that method still works for soft washing to control run off.