I invested in a lightweight scaffolding platform that has wheels and I roll it around the van so that I can wash the complete roof.
That way I do not need to protect the van from ladder dents as nothing touches it at all.
You could always get a folding platform ladder as that would do the same job.
I know that our van is small but I took a small ladder inside the van I then opened the skylight put my bucket on the roof and then put my head through the opening and from the ladder I reached outwards and was able to clean all around the skylight. The rest of the roof was done from a ladder outside. After I had closed the skylight of course
A day of all things motorhome and campervan. The show is held both in the main indoor arena and across the grounds. Catering, hot drinks and food options are available. Easy access to the site and free parking included. Win one of five pairs of day tickets