I use
Camco Wash and Wax for cleaning the RV. I use it on the roof, the sides and front and back and even the awning both top and underneath.
I do this once in the spring and once in the fall.
Once I wash it, I check all the seals around all the roof fixtures (Vents, AC, Antenna, Ladder mounts, Fridge vents, plumbing vents, etc.). If any have cracks, pin holes or places that water may be able to seep into, I apply some
Self Leveling Dicor or some
Eternabond tape, which ever seems to be the best fit for the situation.
Water intrusion is the number one enemy of campers. Your roof, the seams in it near things mounted to it along with the edges where it meets the front, sides and back are high risk area's water can get in. Being faithful about doing inspections and catching any tears, holes, punctures or wearing BEFORE you notice a water stain on the ceiling is the best way to keep your camper in good working condition for a long time.