I'm no expert, but do believe the roofs come w/ something like a 12 year warranty. That being said, I wash ours couple times a year w/ Spic-N-Span liquid soap and use a sponge mop. Rinse area 1st, wash a 3x3-4x4 area at a time, rinse again. End up doing a lot of rinsing. Then wash awnings and coach afterwards. While up on the roof, I take a good look at all the areas of caulking to see if any need addressing or not.
Not that a 2 year old coach should need it, but one could also consider a roof coating like RV-Armor and probly never have to worry about leaks at all. Don't hear much about it (albeit a lil pricey), but may be easier to clean VS a rubber roof.