Spic-N-Span General Purpose Cleaner, water and a bristle brush. Elbow grease and rinse, rinse, rinse. Do NOT let the chalky substance and spic n span dry on the sides of the RV.

-- Edited by 53 Merc on Tuesday 13th of July 2010 08:37:31 AM

I use OxiClean powder that comes in a small bucket. Wet the roof, toss the OxiClean by the handful, and scrub with a rough surface mop. You won't get imbedded black marks out, but it cleans well. The only drawback, and I suspect it's true with any roof cleaner, is that it puts all that roof dirt down the sides of the rig when you rinse.  So do the roof first then wash the sides.

You can also use a handheld pressure washer. Unlike the standard wheel based washer, they don't put out enough pressure to do damage unless you hold the nozzle real close to the roof. The drawback there is that you have to drag around the electric chord and water hose that attaches to them.  

While in Fredricksburg, TX this week, I found the very best roof cleaner. Called him Alex. He runs a come-to-you cleaning service. This guy is an energizer bunny when it comes to cleaning. I guess practice makes perfect. He spent about 1.5 hours on my 32 ft rig, and when he left, the rig was clean, the roof sparkled, the windows were clean, the tires were shiny and I was happy. I was more than willing to pay him his price (even kicked in an extra 20) cause he was so good. I did not even break a sweat.

I bet if you checked at the office of any of the RV Parks in or near Austin, they have several business cards of mobile wash companies. The one I had was called Next Step Mobile Wash. Thing that impressed me was his water system. It was softened water (anion and cation treatment) and RO (reverse osmosis). Since in a past life I did a lot of water treatment for boiler feed water, I knew why he had the system. No wipe down required. Scrub with soapy water and rinse well, no streaks and no window washing required. It all dried spot free. Unfortunately, I do not have the card.