A deck, be it redwood, cedar, pine or other, is a pleasant place for warm-weather entertaining.

More often than not, a deck will be a little worse for wear following the ravages of the fall and winter seasons. This likely is true even if the deck previously was treated with a stain or wood preservative. Dirt, mold, leaf stains, tannins and rust can detract from the beauty of a backyard deck. What's worse, left untreated, mold, algae and moss can lead to significant damage.

The key to keeping a deck looking good is maintenance. Grit, grime and environmental fallout should be removed via periodic washings. In most cases, a couple of thorough washings each year will do the trick. That together with regular hosings will make your deck the envy of the neighborhood. Or almost. There's a bit more to it:

A solution of detergent and water is typically all that is needed to conquer most stains. Try one cup of powdered laundry detergent in a gallon of hot water applied with a nylon truck brush. This brush has a soft bristle with a broom handle and is used for washing vehicles. The soft bristles are effective in dislodging the most minute of particles, and the pole saves having to work on your hands and knees.

Even after the most thorough washing, a deck might still have stains such as wax from a candle or drippings from a cookout. If your deck hasn't been the subject of periodic washings and maintenance, the detergent-and-water solution, mentioned earlier, might fall short. If such is the case, and a complete sanding isn't appealing, a washing with more effective cleaners might do it.

Synthetic trisodium phosphate (TSP) and water is a safe and generally effective way to clean a deck and prepare it for a new coat of finish. Commercial deck-cleaning products are another alternative. Applied with a pump garden sprayer, these products can remove the gunk, but can dull the finish. Hence, be prepared to apply a fresh coat of deck stain or wood preservative once clean. This is a wise procedure, especially for decks that have not received ongoing care.

Leaves that have made a home of your deck's surface through the fall and winter, even when removed, will leave their mark. Leaf stains best can be removed by spot-scrubbing with a one-to-one solution of household bleach and water. Work the solution in, using a nylon scouring pad or 0000 steel wool working in the direction of the grain. In all cases, rinse with fresh water.

Tannin-rich woods can result in black streaks and stains. These stains are often found around nails and screws, and can be virtually impossible to remove. We suggest using a deck-brightening product if this condition occurs.

These also are referred to as wood bleaches. A deck brightener that contains phosphoric acid as the active ingredient is effective and safe to use when applied in accordance with the manufacturer's instructions.

Candle wax can be stubborn. Place a rag saturated with mineral spirits on the dried wax. The rag will absorb the wax. Be sure not to allow the rag to dry out and never perform this procedure in the heat of the day or in direct sunlight, due to potential combustion.

Barbecue grease stains are unsightly and can attract pests. If they don't come out using one of the general cleaning solutions described earlier, try using a water-soluble automotive degreaser or carburetor cleaner. As with the candle-cleaning method, do not apply this product in the heat of the day or in direct sunlight. Rinse thoroughly with fresh water.

Lumber-grading stamps are nearly impossible to remove from the surface of a deck. We have found that even the best of cleaners won't phase them. The only way to remove these enduring marks is by sanding.

Algae, moss and mildew are a slip hazard and the precursor to significant rot. Scrub with a solution that consists of four parts liquid chlorine bleach to one part water. Once clean, a high-quality stain or wood preservative that contains a mildewcide will help to prevent them from returning.

Rust is another stain that one would think could be removed by nothing short of explosives. Actually, the phosphoric acid-based deck brightener that we mentioned usually will handily remove rust stains. In fact, many rust-removal products contain phosphoric acid as the active ingredient. Also, a 5-percent solution of oxalic acid in water applied directly to the stain likely will do the trick. In either case, more than one application might be required.

Finally, the key to maintaining an appealing deck is to protect it from damage by ultraviolet sun rays and water. We suggest that a high-quality oil-base deck stain or wood preservative that contains a mildewcide be applied every two or three years, depending upon exposure and wear and tear. Oil-base products replace the wood's natural resins, moisturizing and preventing cracking, cupping and curling. Although a clear-wood finish can contain ultraviolet inhibitors, a pigmented product offers added protection.