I use a sheetrock scaffold I got from home depot. http://www.homedepot.com/p/PRO-SERIES-6-ft-x-6-ft-x-29-in-Multi-Use-Drywall-Baker-Scaffolding-with-1000-lb-Load-Capacity-GSSI/100645165
had it delivered to the house and liked it so much I went out and wash/waxed the RV. Only problem I had was getting under the overhang. It was easier to lay down to get to it and of course once laying down one can close ones eyes and look like your working ;-) easy set up and one person operation for this 7 decade oldie.