We pressure clean: Houses, Condos, Pool Enclosures-cages, Decks, Driveways and Sidewalks.
We don't power wash roofing, because it's the wrong way to do it! Roofing requires a gentler process, simply because pressure washing is too rough on the roofing, as it is necessary to get quite close, in order to remove the black algae discolorations. The method and cleaning agents we use are those specified by roofing manufacturers and by the ARMA roofing association. You can read what they say here- http://www.bergmanpressurewashing.com/Manufacturer_Specifics.html
My business is licensed and insured and I am a "Certified" roof cleaner and roof cleaning instructor, through the RCIA.
Here you can watch me cleaning a couple of roofs on Youtube -
Here is another, of a tile roof-