These homeowners moved into a house with a beat-up deck. The orange paint was peeling and there was rot in some of the planks. The budget didn't have room for a replacement, so instead, we renewed the deck they already had! Let me walk you through the steps:
1) To start we hand scraped the flaking paint off the surface and sanded down the boards.
2) We replaced the rotten sections with new wood.
3) We pre-filled the cracks and then double coated the deck surface with a pretty great product called Deck-over. It provides a thick layer of protection from the elements as well as traction for human and puppy feet.
While it's a bit labor intensive, there are significant advantages to refinishing rather than replacement. There is a cost savings to be sure, but there's also the gratification of keeping used building supplies out of the landfill.