When it comes to deck maintenance, there are two distinct approaches: You can either let the wood age to a natural gray or you can refinish it every few years. Each has its advantages and disadvantages, but taste and temperament also come into play. Decks are usually made of rot-resistant lumber, so a low-maintenance approach is at least reasonable. On the other hand, a deck regularly treated with a quality stain and sealer will always outlast and look newer than an unfinished deck.
Deck stain is available in a wide array of colors so you can simulate the look of new wood or choose a stain that matches or contrasts with your house. However, once you've applied a finish, you're sort of committed to refinishing. Sealed decks don't weather uniformly. After a few years, areas exposed to direct sunlight may hold no trace of the old finish, while shaded surfaces may show little degradation. At this point, it no longer looks like a finish, it looks like neglect. This is not to say that you can't strip off the remaining finish and then let it all go gray. It's just that most people put on a new coat of stain.
Refinishing can be a lot of work, but when you consider that decks are costly additions, and that most can be refinished for under $100, refinishing makes sense. Of course, if your deck is built with any wood but redwood, cypress, cedar or treated lumber it should be sealed yearly.
Methods and Materials
Deck refinishing is usually a three-step process, consisting of stripping off any existing finish, washing the entire deck with a strong cleaner to remove dirt and mildew, and resealing all the exposed wood surfaces with a clear, semitransparent or solid-color sealer.
You'll find a variety of deck refinishing products at your home center or hardware store. Deck cleaning has really drawn a lot of attention since the proliferation of affordable pressure washers. While pressure washers do a nice job of peeling away old layers of dirt, grease and mildew, as well as old finishes, they're not essential to the task. You'll need to do a little more scrubbing, but if you don't own a pressure washer, and can't easily rent one, a garden hose is a reasonable substitute.
Every deck refinishing job should start with a structural inspection. Check for exposed nail- and screwheads and loose deck boards, steps, railings and benches. You'll find that simply resetting nails and screws will fix many problems, but occasionally you'll need to add new fasteners or replace and upgrade the existing ones. Our box step is a good example. We found that most of the screws securing it to the deck were broken and the step had separated from the deck on one side. To repair it, we removed the tread and refastened the step box with 5/16 X 4-in. lagscrews. Bore clearance and pilot holes in the back of the box and the deck rim joist. Drive lagscrews with washers through both timbers with a socket or open-end wrench. Then, reset the tread and secure it with new 3-in. galvanized deck screws.
Stripping the Old Finish
A mild stain/sealer stripper works best on oil-based finishes and on horizontal surfaces. One gallon treats 150 to 250 sq. ft. If you need to remove a heavy, full-color stain, either latex or oil, then Flood's StainStrip would be a better choice. Before applying strippers, thoroughly wet the vegetation around the deck and cover flower beds with inexpensive plastic tarps. Sweep the deck thoroughly and use a garden sprayer or thick-nap roller to apply a heavy layer of the stripper. Allow the stripper to set for 15 to 30 minutes. Then use a stiff-bristle brush to scour the surface. Don't work on an area larger than you can manage comfortably, and wear rubber gloves when hand scrubbing hard-to-reach spots.
When you've scrubbed the treated area thoroughly, use a hose or power washer to rinse the stripper from the deck. A small piece of plywood set against the house and moved along as you work will help protect the siding from too much overspray. When you're finished, rinse the siding lightly to remove any stripper debris. When using a more aggressive stripper, tape plastic film over the siding, windows and doors.
Washing the Wood
Dekswood needs to be applied to wet wood, so begin by wetting the entire deck. Then, mix one part Dekswood with four parts water and pour the mixture into a deep roller pan. Working on a manageable area, apply the cleaning solution with a stiff-bristle brush, scrubbing vigorously as you go. When you've finished scrubbing your target area, use a pressure washer or hose to scour the surface clean. Then move to the next section of the deck and repeat the procedure. When the entire deck has been scrubbed and rinsed, use your garden hose to rinse off all nearby vegetation.
Sealing and Staining
CWF-UV is a penetrating oil finish stain sealer that contains UV (ultraviolet) protection and a semitransparent redwood stain. Although this is an oil finish, the oil is carried on latex emulsifiers, so all equipment cleans up with soap and water. We chose a semitransparent stain because our 5-year-old deck is old enough to need a little help in looking new, but not so weathered as to justify a solid-color stain. With a 1-year-old deck, a clear sealer would be more appropriate. Our roughly 400-sq.-ft. deck soaked up a little under 2 gal. Applying a stain/sealer is like painting in most respects, but conditions need to be just right. Because you've just drenched the deck, it will need two to three days to dry. And because the sealer needs several hours to work into the wood's surface, it's best not to start this project in the midday sun or on hot days. Early morning or early evening is probably best, and keep an eye on the weather report because the finish should cure for a couple of days before getting wet.
Begin by masking off areas to be protected such as siding and the concrete at the base of the steps. Pretaped masking paper is quick and easy to use and is available wherever paints and finishes are sold. It's best to apply the stain on the broad areas of the deck with a roller and reserve a paintbrush for working up to the masked sections and in tight areas. Because a brush applies less stain than a roller, generously load the brush with stain. If you put on too much, you can always back brush before it dries completely. Avoid overlapping wet sealer on sealer that has dried or the overlapped area will dry to a darker color. After working along the house with your brush, cut in around the bench and railing supports.
When you've finished with the brush work, use a roller and a 3/4-in.-nap roller cover to apply stain to the larger areas. A heavy roller cover does a good job of pressing stain into the gaps between boards. And when you're finished, watch the stain as it dries. If you see any shiny puddles of stain, tiptoe onto the deck in clean shoes and back brush those spots to blend them into their surroundings.
Copyright © Popular Mechanics 2001. Reprinted by permission.