Roof on my RV is built so I can was it. When I have work on outer edges I use a 10' stepladder to access those areas.
For the cab-over area I use the same 10' stepladder and a 7' stepladder. Clamp a 12" X 12' plank between between them. This allows access to the front cap and small part of roof. I have seen where others get a rolling scaffold from Harbor Freight that give them access to high areas.
When I do not have access to the stepladders I use a brush on a 8' pole to wash the cab-over. Waxing the cab-over will have to wait until I get back home.
2004 Gulf Stream Endura 6340 D/A SOLD
2012 Chevy Captiva Toad SOLD