No one wants to spend his summer cooking and entertaining on a splintery deck. Summer means bare feet; bare feet and splinters simply don't mix. If you haven't treated your deck in a few years, it's likely that water has seeped into the wood causing it to crack, splinter, and even warp and twist. A neglected deck can be repaired, even if you can't get it back to its original splendour.
Mix a cleaning solution of half bleach and half water. Spray down the deck with the help of a power washer. The bleach will bring the wood back to a uniform colour and help bring out the natural wood look you're trying to recover. Keep the tip of the power washer away from the deck to avoid further damage to the wood.
Let the deck dry for three to four days.
Sand the deck with a random orbit sander and 80-grit sandpaper. You can sand the railings, stairs and anything else by hand or with a belt sander.
Clean the dust off the deck with a power washer on a low setting.
Treat the wood with water sealer or wood protector if you're concerned about maintaining the natural wood colour. Wood protectors require more frequent application than sealers, according to HouseTask.com. The sealer can be sprayed on or applied with rollers and brushes.