Hi, I've been asked to do a roof clean on a 5 bed house. (would be my first ever roof clean, apart from small flat roofs) First thoughts were to use a pressure washer but I've read so many horror stories and bad things about using them on roof tiles - so I'd rather not. I've been looking at this system : http://www.algoclear.com/content/14-equipment Trouble is although they mention some of the stuff they use, they don't appear to sell the system. Does anyone know where I could get a ready made spray system? If I can't get hold of one/too expensive, I was just going to use the moss-go treatment on the roof and get up there using a scaffold tower/roof ladders and a couple of those "backpack" spray things with a lance. Any thoughts?