Decks will often need cleaned and protected approximately every 3-5 years. It varies on the quality of the products used to protect the wood. The process is not difficult, but it can be time consuming. It is important to do so as to protect the value and pleasure a deck can give.
Be sure to remove leaves and debris off the deck and especially from the cracks. Stuff trapped in these areas will hold moisture and help cause premature aging of the wood.
After the deck in cleaned, time to apply a protective coating. There are many to choose from. You will need to visit a store to see all the possibilities.