To remove mildew and fungus from a deck, clean the surface with a stiff-bristle broom; use either a commercial deck cleaner or mixture of 1 cup of chlorine bleach to 1 gal. of water. Rinse thoroughly– chlorine-salt residue turns wood gray. To brighten the deck, use a commercial brightener, or mix your own with sodium percarbonate (1 cup per gallon of water), a powdered bleach ideal for removing dirt, mildew and gray residue. To remove dark spots on redwood, cedar or oak, use diluted oxalic acid.
