How to Remove Stains on Decks & Porches

Weather, pets, messy eaters, and landscaping conspire to make decks and porches lose their good looks. Here's help for removing specific stains.
Wood Surfaces

These remedies will help remove stains on wooden decks or porches.

Stain
Remedy
Mildew
Clean the surface with a commercial deck cleaner/brightener. If it is not in liquid form, mix the powder concentrate with the recommended amount of water and apply with a garden sprayer, brush, or roller. Wait several minutes, then brush briskly with a stiff brush or broom. Rinse with a garden hose. Some cleaners may contain acids or chlorine, which can harm plants; check your label.
Candle wax
Saturate a rag with mineral spirits. Set the rag on the dried wax until it absorbs the wax. You may rub lightly.
Barbecue stains (including grease and sauce)
Scrub with a strong household detergent or water-rinsable automotive degreaser or carburetor cleaner. Rinse the area before it dries.
Tannin
Remove the black streaks of tannin-rich woods with a specially formulated tannin cleaner.
Rust
Apply a solution of water and 5 percent oxalic acid to the stain. Let it sit for several minutes, then rinse.
Leaf stains
Spot-scrub the area with a 1-to-1 solution of household bleach and water.
Green algae or moss
These stains are difficult to remove and usually reappear once the roots are formed in the wood, but you can temporarily eliminate them by scrubbing with a solution of 4 parts bleach to 1 part water.
Sap
Scrape excess material with a putty knife or steel wool. Wipe with turpentine.

Continued on page 2:  Concrete, Flagstone, or Brick