People love the easy-maintenance of Mendocino Redwood decks, as well as the beautiful color of this natural, extraordinary wood. For this reason, many redwood homeowners, when 
constructing their deck, choose to go with a clear stain that shows the grain and color of the wood. Generally, all that is required to keep a Mendocino Redwood deck looking like new is an occasional rinse with water and a reapplication of finish approximately every 12 to 18 months. Mendocino Redwood’s natural resistance to insects and decay make this material particularly durable and long-lasting. Even more stubborn discoloration from dirt or mildew can be easily removed by cleaning redwood with a solution of warm water and mild soap and scrubbing with a soft bristle, non-metallic brush.
Over time, however, wood exposed to direct sunlight or frequent rain can weather and fade. In this case, with a little effort and appropriate supplies, refinishing redwood and restoring it to its original color is easy.
First, remove all dirt and debris with a power washer (use low setting to avoid damaging the wood fibers) or warm soap and water and a bristle brush. For mild cases of mildew, scrub with the soap and water solution, and then rinse with a household bleach solution to kill any living spores. Rinse thoroughly with water to remove excess bleach.
Next, to remove more extensive mildew stains and to restore the deck to its natural color, mix a solution containing one cup trisodium phosphate (TSP) and one cup of liquid bleach for every one gallon of water. Scrub with a soft bristle brush and then thoroughly rinse the surface of the deck. Next, make a second solution containing 4 ounces of oxalic acid crystals for every one gallon of warm water. Apply the solution evenly with a soft brush, and then wait until the surface dries. Then rinse with water. After the surface has completely dried, apply a coat of stain to the newly restored surface.
