With Michigan's weather as it is, deck and patio surface maintenance is an important and time consuming chore. There is a product I have tried by Synta Inc. called Deck Restore.
This product actually encapsulated the decking boards and fills cracks for a durable long lasting finish. Synta Inc. also has a product for concrete called Concrete Restore.
You can watch a product video here: http://synta.com/deck_video.html or go to the Synta Inc. website here:http://synta.com/index.html Restore is available at Home Depot and possibly other retailers in the area.