Matt
Yeah I know it has roof tiles ::)are they slate,granule coated concrete?I can clean most slate roofs from the ground with my kit but anything else you are probably looking at p/w with safety harnesses,access lifts,life lines the full monty(Health & Safety :-/) I wouldn`t recommend using cherry pickers for this kind of work Power washers and ladders don`t mix I`m afraid,my machine can put out 12ltrs a min at around 4,500psi which adds up to a kick like a mule when you pull the trigger!