5 Ways to Protect Your Deck

It's easy to think a sturdy wood deck should be relatively impervious to the elements, for a few years, at least. The truth is, though, that decks take a lot of punishment over even a single season. The flat surface of a deck responds to the elements somewhat differently from, say, a wooden wall. Water dwells on the wood longer, and sunlight can be more concentrated and damaging because there's no overhead protection. Foot and pet traffic, as well as moisture problems caused by landscape plants and other objects obstructing good air flow can make your deck age prematurely, too.

Over time, nails can partially work their way out of deck floorboards and cause injuries. Boards may warp or crack, dirt and dead leaves can accumulate between the floor boards and bird droppings, dirt and pollution can stain and discolor the finish. These things don't happen all at once, but keeping a sharp eye out for evidence of insect activity, mildew growth, loose treads on the stairs, ponding and wobbly railings can do a lot to help you understand how your deck is aging and develop a strategy for effective seasonal maintenance.

You can keep your wood or composite deck looking good longer by getting a jump on potential problems. Sweep your deck frequently. Don't let leaves, especially wet leaves, accumulate. Keep shrubs from growing within a couple of feet of your deck, especially on the shady side of your property. Use a five-in-one painter's tool to keep the gaps between the deck's floorboards free of accumulated debris. Clean food stains and bird droppings as soon as you notice them. If you have potted plants on your deck, elevate them to allow airflow underneath, or move them periodically.

There are other measures you can take, too. Like the hardwood floors in your home, your deck is vulnerable to scratches and gouges. Your dogs' nails and even high heeled shoes can scratch the wood if you aren't careful. Lift furnishings before moving them onto or across your deck, keep your pets' nails trimmed, and think of your deck as another section of flooring in your home.

An unprotected deck will deteriorate quickly. Even though pressure treated wood resists rotting and insect predation, it will still crack and split from water exposure. The only way to protect your deck successfully over time is to apply a deck preservative. There are sealers, stains and paints on the market especially designed for deck use. Aesthetically, they look very different, but they protect wood and composite decks from moisture damage, fungus growth and ultraviolet light. Some also have built-in fire retardants.

Deck protection products are effective, but they have one big drawback: They lose their ability to protect wood over time and have to be reapplied. Usually, the more expensive the product, the longer it will last between applications, but there's no magic bullet that will offer lifetime protection for a wood deck. The most important thing you can do to protect your investment is to reapply a wood sealer on a regular basis, typically in fall when the temperatures are stable and rain isn't forecast for a week or more. Once a year is considered pretty standard, but newer formulations may reduce the reapplication frequency to once every three or four years -- if you're lucky.

No deck preservative will work effectively unless you apply it when your deck is clean, and prepping a deck for its periodic coat of waterproof sealant can be a big job without the right tools. Many of the pros use pressure washers together with cleaning and pretreating products designed to lift grime and remove loose wood particulates. One of the most popular and effective pretreaters these days is oxygen bleach. It has a foaming action that helps cut down on the amount of scrubbing required and is an environmentally friendly and landscape neutral choice. Chlorine bleach and TSP (Trisodium Phosphate) are other popular options, but both can be caustic and have a negative impact on the environment.

There's some debate among the experts about the use of pressure washing equipment to clean wood. Detractors say that high water pressure destroys the surface of many common wood products, leaving wood so rough that it may require resanding. Proponents claim that the wear and tear is minimal while the advantages of a quick cleanup make it worth the risk. If you do go the pressure washer route, use the lowest setting that will do the job. Try starting with a pressure of around 500 psi (a rating of pounds per square inch), and work your way up from there. Read up on using a pressure washer on wood, too. Cleaning spindles and stairs may require a shorter wand for tight corners. Maintaining a smooth, even motion is important, too. When it comes to deck cleaning, good wand work isn't just reserved for Harry Potter and the wizarding world [source: Haege].

After your deck is clean, give it plenty of time to dry completely. Three dry days at temperatures above 40 degrees Fahrenheit (4 degrees Celsius) will insure that the deck is dry enough to apply sealer effectively [source: How to Clean Things].

Building your deck may have been about aesthetics, but maintaining it is about following directions. Wood looks pretty indestructible, but it isn't. When you use a power washer or opt for a particular stain or protector, you're using powerful solvents and equipment. Deck maintenance products are designed to be used in a specific manner. Almost all of them will cause problems if they're not applied in accordance with the manufacturer's instructions.

It may sound hokey to reinforce the fact that you should read the instructions carefully on the products you use, but the fact is that not doing so can cause headaches you don't want when maintaining your deck. For example, using a pressure washer against the grain of the wood can cause unsightly cut marks that won't go away without sanding. Applying sealer in cold weather, before a rain or on damp wood could keep your deck tacky and sticky for days or even weeks -- and never net you the sleek, finished look you want. What's even worse is that any mistakes you make this year will come back to haunt you next year and the year after that. Keep it sweet and simple: Read and follow the directions every time.