Barbara and Phil Johnson, of Mobile, Alabama, faced the same problems other deck owners do. Over the years, the elements as well as their kids and pets took a toll on their backyard deck. The damage and the appearance were bad enough for the Johnsons to consider ripping the whole thing up and starting over.

But before taking that drastic step, they spoke with Danny Lipford, owner and president of Lipford Construction in Mobile, for advice. According to Lipford, the Johnsons’ deck was in better shape than many others. “This area of the country is tough on decks,” he says. “I’m sometimes asked to replace pressure-treated decks that are less than eight years old.” He adds, “Most of these decks are victims of neglect. With regular maintenance, a deck will easily last for twice as long.” The good news is that most decks, like this one, can be rejuvenated for a lot less than the cost of replacement.

Following are some techniques you can use to give an old deck a new lease on life, or to help maintain the look of a new one. For this project, we enlisted George Graf, a lead carpenter with Mobile’s Lipford Construction, and John Starling, owner of John the Painter. Hiring pros is easy on the schedule but hard on the budget—the cost of repairing a 700-sq.-ft. deck is $700, or about $1 per square foot. Restoring a deck yourself will cost a third as much.

A deck rejuvenation project like this can be done in two days, but it’s best to spread the work over two weekends to ensure the wood is completely dry before you apply stain.

Step 1: Making Repairs

Begin by inspecting the entire deck. Pay special attention to any part of the deck that is in direct contact with the ground, such as the posts, stair stringers or joists that are at ground level. Graf uses a screwdriver to check for structural damage. “If you can sink the tip of a screwdriver into a post or joist, it means the you’ve got rot and it’s time for a major renovation,” Graf says.

Also, inspect the deck-to-house connection. “Screws and bolts can loosen and rust,” he says. “Without the proper use of spacers and flashing, moisture can cause your band joist to rot.”

Tighten the fasteners that attach the deck to the house, look for any missing, bent or rusted flashing and carefully inspect inside and out for any telltale black stains that suggest moisture is working its way into your home.

Next, look for any cosmetic damage. For example, tap down any popped nails or consider replacing them with screws. For the Johnsons’ deck, Graf used galvanized ring-shanked nails when he replaced a few damaged boards. “Screws don’t pop like nails, ” he says “but we want the new boards to match the rest of the deck.”

Tip: If you need to rip replacement decking to match existing boards, use a tablesaw. Ease the sawn edge using a router fitted with a ⅜-inch roundover bit.

Carefully inspect railings and decking for loose wood. “No one likes to catch a 2-in.-long splinter on the hand or foot,” Graf says.

Step 2: Cleaning the Surface

Here’s the bad news: Every deck should have an annual cleaning. Assuming they have been maintained regularly, most decks can be revived with just a deck cleaner. Some products, like Thompson’s Deck Wash ($10, 1 gal. covers 250 sq. ft.), you mix in a bucket and apply to the deck; others, like GE’s Weathermate ($30, 1 gal. covers 500 sq. ft.), come in containers with integral applicators that you hook up to a garden hose. Once on the deck, most still require a stiff-bristle brush and a lot of elbow grease to work the mixture into the wood.

Always wear eye protection and gloves when working with concentrated chemicals. You’ll also want to protect nearby plants. The level of plant protection depends on the type and concentration of the chemicals you choose. For weak solutions and “plant-friendly” cleaners, you may need to only mist the plants before and after using cleaning. Powerful deck restorers can burn leaves on contact; in that case you should cover nearby plants with plastic sheeting.

For tackling tough stains, use a pressure washer (about $70 a day), which is the best way to remove sun-damaged wood fibers and tackle scrub-resistant stains. Graf recommends using a fan-type nozzle instead of a pinpoint nozzle that can dig into the wood. For removing the mildew, Graf mixes his own cleaning solution (see “Choosing the Right Cleaner,” on the facing page), which he feeds into the intake hose on the washer.

Go over the deck with a stiff-bristle brush to work the cleaner into the wood fibers, and then rinse. The boards should be kept damp in order for the cleaning solution to work effectively. Allow the deck to dry thoroughly before staining.

Choosing the Right Cleaner
There are dozens of deck-cleaning products on the market. Most contain one of the following four chemicals as their main ingredient. Each is effective for different types of stains.

Sodium hypochlorite: This chemical—chlorine bleach—is good for removing mildew but isn’t effective on dirt or other stains. So mix it with an ammonia-free detergent. Thoroughly rinse the deck after using this chemical because it can eat away at the wood, resulting in fuzzing and premature graying.

Sodium percarbonate: When mixed with water, this chemical forms hydrogen peroxide (an oxygen-based bleach) and sodium carbonate, which acts as a detergent. It is good for removing dirt, mildew and weathered wood.

Oxalic acid: This is effective in removing iron stains and the brown-black tannins that frequently occur with cedar and redwood decks. This acid is commonly found in deck brighteners. Oxalic acid isn’t effective against mildew, so you may want to use it after cleaning the deck with a bleach-based cleaner.

Sodium hydroxide: Also known as lye, this is the key ingredient in most finish lifters or removers. Don’t leave it on too long, or it can eat away at the wood.

Be very careful when working with any of these chemicals, especially when they’re in their most concentrated (premixed) form. Wear the proper safety equipment and follow the manufacturer’s directions to the letter. Rinse the surface thoroughly and allow it to dry before refinishing.

DIY CLEANER
Here’s a deck cleaner you can make yourself. Recommended by the U.S. Department of Agriculture Forest Products Laboratory, it’s good for mildew and dirt.

• 1 qt. sodium hypochlorite solution (household bleach)
• ⅓ cup powdered laundry detergent
• 3 qts. warm water

In a 5-gal. plastic bucket, add the bleach and detergent to the water, then brush the cleaner onto the deck. Rinse thoroughly before applying a finish.

Caution: Do not use a detergent that contains ammonia. Ammonia and bleach react to form a poisonous gas.

Step 3: Applying the Stain

Once all of the repairs have been made and the deck is clean, it’s time to apply a protective finish. Clear finishes and transparent stains are fine for new wood, but for older decks, Starling recommends using a semitransparent stain.

“The grain still shows through, but the pigment gives the old wood a clean, uniform color and helps the new wood blend in,” he says. The pigment also provides extra protection from the damaging effects of the sun and will last longer than clear finishes. Unlike paint, stain is absorbed by the wood and does not form a film on its surface, so it will not peel or chip.

Starling uses a sprayer and 2-in. brush to apply the stain. “Spraying is fast, and puts more stain on the wood than rolling or brushing,” Starling says. Most painters and homeowners are better off spraying on a generous coat of stain and then following up with a roller or brush to spread out puddles and work the finish into the wood. Starling, however, uses a modified technique. “Rollers push the stain off the wood and down the cracks,” he says. “I don’t get paid to paint dirt beneath the deck.” Starling sprays on a light coat, most of which is quickly absorbed into the wood. He uses the brush to remove puddles. “If the stain’s too thick, it dries blotchy,” he explains. Starling recycles the excess stain for use on exposed end grain.

Starling recommends starting at an inside corner and working out, applying the stain parallel to the deck boards. To avoid staining the nearby brick, he uses a small piece of cardboard as a spray shield; the brush provides even more control around deck railings and posts.

This 700-sq.-ft. deck required about 5 gal. of stain — almost twice as much as the estimates indicated on the can. Explains Starling, “Old wood can get thirsty. On some decks, I’ll need to apply two or three coats of stain in order to get a uniform finish.”

Subsequent coats should be applied while the first coat is still wet or they will not be absorbed into the wood. Stain won’t peel, but it can wear away, especially in high-traffic areas. Starling recommends applying a fresh coat every other year. A clear water repellent can be applied between stainings for extra protection.