Gray boards and water soaking in: how to tell your deck or fence needs stain

How to tell in five minutes

Your deck or fence needs stain when the color has faded or turned gray, when water soaks into the boards instead of beading on the surface, or when you see mildew, rough raised grain or fine cracks spreading along the wood. Loss of color is the clearest early sign; federal preservation guidance from the GSA calls it a good indication that the finish must be renewed. If the wood is still firm, restaining now protects it. If boards are soft, loose or warped, they need repair before any stain goes on.

I am Andrey Shelokovskiy, owner of Nomad Painting, and we clean and stain decks, fences and pergolas along with our painting work. My background is in protective coatings: six years at PPG Protective and Marine Coatings and membership in NACE, the corrosion engineers' association. A stain is just a coating that soaks in instead of sitting on top, and it fails for the same reasons any coating does. Here is how to read your own wood.

What sun and rain do to unprotected wood

Bare wood outdoors starts breaking down at the surface almost immediately. Ultraviolet light attacks the fibers and the natural color, which is why cedar and pine go silver-gray after a season or two without protection. Rain then washes away the loosened fibers, the surface roughens, and small cracks called checks open along the grain. Those checks hold water, which speeds up the cycle and invites mildew.

In North Texas the combination is hard on wood. Long, intense summers bake horizontal surfaces like deck floors and fence caps, sudden storms soak them, and the wood swells and shrinks with every swing in moisture. A deck floor faces the sky all day, so it always wears faster than the railings or the fence boards that stand upright. When I look at a deck, the floor tells me how the whole finish is doing, and the shaded corners tell me where mildew will show up first.

Pergolas sit somewhere in between. Their beams and rafters take full sun on top and stay shaded underneath, so the top faces gray and check while the undersides can stay surprisingly fresh. Because the tops are hard to see from the ground, pergolas often go years past the point where they needed stain. If you have one, get on a ladder once a year and look at the upper surfaces.

Five checks you can do on a dry afternoon

Pick a dry day when the wood has not been wet for at least a couple of days. You need a glass of water, a dark cloth and a screwdriver.

• Water test: sprinkle water on the deck floor and a fence board. If it beads, the finish is still working. If it darkens the wood and soaks in within a minute, the wood is unprotected.
• Color check: compare a sunny board with a shaded one or with wood under a planter. A big difference means the exposed finish is gone.
• Touch test: run your hand along the boards. Rough, fuzzy or splintery wood has lost its surface and needs cleaning and stain.
• Mildew check: look for gray, green or black spots in shaded areas and along the bottom of fence boards.
• Screwdriver test: press the tip into the wood at the base of posts, at board ends and near the ground. Firm wood is fine. If it sinks in, there is rot.

A worn finish or a structural problem?

Stain protects sound wood; it does not fix wood that has already failed. If your checks found soft spots, boards that have cupped or warped badly, popped nails or screws, or posts that move when you push them, deal with that first. Federal guidance on staining lists warped boards and loose fasteners among the signs of weathering, and I treat them as repair items, not painting items.

A fence that leans after a storm is a carpentry question, and the answer may be a few new posts or a full replacement. A fence and deck specialist explains how to tell whether a leaning fence needs repair or replacement, and it is worth settling that before you spend money on stain. Staining a fence that is about to come down is money lost.

If the wood is firm and straight and only the finish is gone, you are in the good position. Clean it, let it dry and stain it, and the wood under it will keep its strength for years.

Transparent, semi-transparent or solid: what each one means later

The stain you choose decides how the wood looks and how it ages. We offer three types, and the choice is mostly about how much grain you want to see and how much upkeep you will accept.

Transparent stain shows the most grain and offers the least protection from sun. On our own projects we use it only on new wood. Semi-transparent stain adds pigment, which blocks more ultraviolet light while still letting the grain show. The GSA describes semi-transparent penetrating stains as soaking into the wood, and notes that they will not peel, flake or blister the way a film does. Solid stain looks more like paint: it hides the grain and the color of the wood and forms a film on top. That makes it good at covering mismatched or older boards, but the GSA notes that film-forming stains can peel just as paint does, and it does not recommend them for flat horizontal surfaces such as deck floors and handrails.

For most decks I recommend a semi-transparent stain on the floor and railings. On a fence, solid stain can make sense when the boards are a patchwork of old and new, since it evens out the color.

How often a stained deck or fence needs attention

There is no fixed calendar, because exposure decides it. The GSA's guidance for oil-based semi-transparent stains gives a single coat on smooth wood a life of about 2 to 4 years and a two-coat system up to about 8 years, depending on exposure. A deck floor in full sun will sit at the short end of any range. A shaded fence will last longer than one facing west.

Rather than counting years, use the checks above once a year, ideally in spring. When the water test starts failing on the deck floor, restain the floor. Railings and fences can often go a little longer. Catching it while the old stain is merely faded is cheaper than waiting until the wood is gray and fuzzy, because a weathered surface needs more cleaning and sanding before it will take stain evenly.

How we restain a deck or fence

A good stain job is mostly cleaning and patience. The steps below are how our crews do it, and they are a fair standard to hold anyone to.

Long fences are where patience shows. One client's Google review describes 570 linear feet of cedar fence we restored, and a run that long is mostly a cleaning and drying job before it is a staining job. Rushing the drying to finish a day early is how fences end up blotchy.

• Confirm the stain color and the scope, and protect plants, siding and hard surfaces nearby
• Power wash to remove dirt, mildew and loose old stain
• Let the wood dry; our process calls for moisture below 17 percent before stain goes on
• Apply stain from top to bottom, starting with spindles and railings and finishing with the floor
• Add a second coat with acrylic, water-based stains where it applies
• Clean up, leave labeled stain cans for touch-ups, and walk the finished work with you

Why weather matters more for stain than for paint

Stain has to soak into the wood, and wet wood cannot absorb it. That is why we wait for the boards to dry after washing, and why a rain shower the night before can push the schedule. The GSA's own procedure is even stricter than ours: it calls for wood below 12 percent moisture, an air temperature between 50 and 95 degrees Fahrenheit unless the manufacturer says otherwise, no application in direct sun and none on damp surfaces or in misty weather.

Wind is the other factor. Spraying stain on a gusty day sends it onto cars, siding and the neighbor's fence, so our crews reschedule rather than spray in bad conditions. If you are planning a deck or fence project along with exterior painting, my guide on when to paint a house exterior in North Texas covers how we plan around Dallas weather through the year.

Making the new stain last

Once the stain is on, a little upkeep stretches it. Sweep leaves and debris off the deck so they do not hold moisture against the boards. Keep sprinklers from soaking the fence every morning. Trim shrubs back so air moves around the wood. Rinse off pollen and dirt in spring, and touch up worn spots on railings and steps with the labeled can before they go gray.

Each year, repeat the water test. When the floor stops beading water, it is time. For more on how to care for a finished project, including what a written warranty does and does not cover, see my guide on making a new paint job last.

If you would like us to look at your deck, fence or pergola, the first step is a free estimate visit anywhere in our Dallas–Fort Worth service area. We check the wood, tell you whether it needs repair first, recommend a stain type and send an itemized estimate.

Questions people ask me