Strip and renew wood before restaining
If the stain on your deck is weathered and peeling, the first step in renewing your deck is to remove all the stain. Solid-color stains protect wood decks and look great when new, but even the best eventually flake and wear away. At that point they need to be scraped and stripped off before the deck can be recoated.
First, scrape off as much of the old finish as you can with a paint scraper. As you scrape the wood, reset any nails or screws that stick out from the wood surface.
Next, strip the deck with a special deck stain remover (1 gallon covers 100 sq. ft.). Tape plastic over nearby siding, cover or wet down bushes and grass around the deck, then spread a heavy coat of stain remover over the stained boards. Cover 20 to 30 sq. ft. at a time, keeping the wood wet until the finish is soft enough to be scrubbed off with a stiff brush (Photo 1).
Rinse the residue off with a hose and allow the deck to dry. Use a stripping disc on areas that are heavily discolored or where the stain doesn’t come off (Photo 2). The rough discs work much faster than belt or orbital sanders. They’re available for either angle grinders (the fastest option) or drills (much slower).
Finally, apply a deck brightener/conditioner (Photo 3) to neutralize the stain remover and clean and restore the wood to something close to its original color. One gallon covers roughly 200 sq. ft.
After the wood dries, restain or apply a clear penetrating finish. Clear finishes show more of the wood’s original color but must be reapplied every year. Solid stains protect the wood longer but can be a pain to scrape off. Penetrating stains also need to be reapplied more frequently, but unlike solid stains, they don’t need to be stripped off.