What should I use to finish an 8-year-old pressure treated deck after pressure washing and sanding? Will teak oil work?

Maintaining a wooden deck finish is more work than most people realize, and that’s why it’s important to consider the long-term consequences before you make a finishing choice. Although I do like teak oil as a finish for exterior wood, it’s not usually recommended for decks. Foot traffic is the reason why. The grit and abrasion that happens to any deck will wear out an oil finish pretty quick. A better option is one of many different approaches, depending on the look you like and the maintenance responsibilities you want to take on.

• The Natural Approach: The easiest approach is to strip, pressure wash and sand what you’ve got, then leave the wood to weather naturally. This won’t shorten deck life, though it will lead to a grey, barn board kind of look that doesn’t appeal to everyone. If weathered grey sounds good to you, I recommend you treat the wood with a one-time application of spray-on, water-based wood treatment. The kind I’m thinking of creates an even, weathered appearance that’s much nicer than the spotty, natural weathering that sets in otherwise.
• The Clear Water Proof Approach: If you’d like to preserve the look of bright new wood as long as possible, then a clear water repellent is worth looking at. Thompson’s WaterSeal is one widely available option. Just be careful to apply only one, thin coat on the wood, and be prepared to refresh the finish every year or so. Preparing the wood for reapplication is easy, since the previous coat is so thin.
• The Clear Stain Approach: Transparent stains are another option that I know makes decks looks great. The best I’ve used last for up to 36 months in full sun, though they do require the use of stripping liquids and sanding to re-establish the finish later. It’s a lot of work.
• The Opaque Stain Approach: The longest lasting deck finishes are opaque like paint, and they maintain a good appearance for 3 to 5 years. The main downside is that they don’t let wood grain show through.

To learn more about the details of finishing old decks and new ones, download a free copy of my deck finishing report.