Assuming it's an EPDM rubber roof, most any "wax" type product will work for awhile, but I doubt if any will last a year. Maybe 3-4 months. A household floor wax works - gives some protection without making the roof dangerously slippery. Harder wax products last longer but may be dangerous to walk on when needed. So-call Rubber roof sealers aren't any better than a floor wax, but it does help the economy by increasing the amount of $$ in circulation.
If its a fiberglass rood, re-paining iot the solution and the Dicor fiberlgass roof paint is one good choice. A marine deck paint would work well too, as would an automotive type apray paint.
