Here's a demo I did for a customer on a very conspicuous area of their metal roof, right over their front porch. They had used pressure washers (for $500) in the past to blast away at their roof and said they couldn't justify the $2400 to SoftWash.
I used a 3% CH solution, sprayed, agitated, rinsed, then applied bleach wash to neutralize and act as a final buffering agent. They were blown away and committed to the whole job. Their next door neighbor came over and saw the demo patch while we were wrapping up and, having the exact same kind of roof, also pulled the trigger on his roof for $1500.
Sometimes going the extra mile for a customer goes a long way to closing the deal... Demos sell!!
I have to see a client today he has a metal roof he does not want them to climb over the roof. Is a second floor. Here I need your help tell me what the mix to use. Chlorine and final wash. I do not know how much to charge