We have a good long term game plan approach for roof cleaning and roof maintenance. A no pressure system, no brushing or washing. It involves regular treatments for good maintenance and regular air blowing of the dead moss. We are able to get most of the moss off within a year to a year and half ish. Each situation is a little different. If you need all the moss removed in one day, we can do that as well. Each roof tells its own story and we can whisper to it to figure out which method will be the best game plan long term.
This photo shows after just one treatment one air blow. The white streaks on the roof is another application of treatment (suds) which will dissipate in less than an hour. Again, this is without even putting a brush or washer to the roof.
I can very evidently spot the difference in the picture uploaded above. But can you elaborate a bit on the procedures, methods and the costs?