I clean and put EPDM roof protectant on it as well as wash/wax the entire rig every six months. Now the truth: It is done every six months, but I don't do it. Vertigo problem so no roof for me and too lazy for the waxing. Fortunately I have a couple of locals guys that do it for a reasonable price. The wax guy does my truck also.
2006 GMC 2500HD CCSB 4x4 Duramax/Allison, Titan 52 gallon fuel tank, Prodigy Controller, B&W Companion Hitch
2010 Jayco Designer 35RLTS, Cummins/Onan RV QG 5500 EVAP, Progressive Industries EMS-PT50C, TST Systems 507 TPMS, RV Flex Armor Roof