If you have a cedar deck, you should make sure that the deck legs are not sitting on dirt or exposed ground. A new deck should never be installed with such either. Doing so will cause excess rot and decay of your deck's support system, making it dangerous to use and enjoy. All deck legs should have footings that are above grade (ground level). Here are some steps to fixing the deck yourself. 1. Raise the deck back to level using jacks under the legs. 2. Cut the rotten portion