Doesn't need sealed? That's a myth that needs busted. Cedar decks will turn gray within 30 days without sealer. Today's cedar is not the old heartwood that our parents and grandparents are used to. It's younger cedar that is harvested earlier. It's not as dense and doesn't have as much natural protection as the old stuff, but at any rate, cedar needs sealed or it's going to do just what you said; crack, peel, and check.