A deck isn't one material with one cleaning method. What works on natural wood can streak composite decking, and what's safe for Trex isn't automatically safe for a cedar deck. Here's how we approach each one.
Click below to see how we approach each material and why it needs a different method.
Natural wood decking, cedar, pine, and pressure-treated lumber among the most common, is porous and pressure-sensitive. High pressure raises the wood grain, creating a rough, fuzzy texture that never fully smooths back out, and can strip stain unevenly, leaving lighter and darker patches. We use low pressure paired with a cleaning solution formulated for wood, which lifts algae, mildew, and graying without damaging the fibers themselves.
Wood left uncleaned tends to gray and weather unevenly as UV exposure and moisture break down the surface fibers differently depending on sun and shade patterns across the deck.
Composite decking, a blend of wood fiber and plastic, is more pressure-tolerant than natural wood but not invulnerable. Most manufacturers recommend a wider fan spray and moderate distance rather than a narrow, concentrated stream, and cleaning in the direction of the board's grain pattern to avoid visible streaking in the surface texture.
Composite's biggest recurring issue isn't rot, it's mold and mildew staining sitting on top of the surface and in the texture grooves, which responds well to the right cleaning solution without needing aggressive pressure.
Trex and other capped composite products add a protective outer shell over the composite core specifically to resist staining and fading, but that cap can still show streaking or dulling if cleaned with the wrong technique. We treat capped composite similarly to standard composite: moderate pressure, wide fan pattern, and a cleaning solution rather than force to lift mildew from the surface.
Because the cap is designed to resist deep staining, most Trex decks respond very well to cleaning and can look close to new afterward, without the color unevenness that sometimes shows up on natural wood after cleaning.
Algae, mildew, and mold on a deck are living growth, the same category of problem as house washing and roof cleaning, just on a horizontal, walked-on surface. A cleaning solution formulated to break that growth down does the actual work; low to moderate pressure is there to rinse it away, not to blast it off. This is why two decks that look equally dirty can need different pressure and dwell time: a shaded, mildew-heavy deck needs a solution with more contact time, while a sun-exposed deck with mostly surface dirt needs less.
Stain applied over algae, mildew, or old failing stain won't bond properly and will peel or wear unevenly far sooner than it should.
Graying wood often benefits from a brightening step after cleaning to restore a more even, natural tone before stain is applied.
Removing trapped moisture-holding growth before it works into the wood grain protects the deck's structural lifespan, not just its color.
Most decks benefit from cleaning once a year, ideally timed before staining season in spring.
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Wood and composite fences face the same algae, mildew, and graying issues as decking, just vertically instead of underfoot. We clean fences using the same low-pressure, solution-first approach, and it's often bundled into a deck cleaning visit when a wood fence borders the deck or backyard. As a smaller, standalone service for now, ask about fence cleaning alongside any deck, house washing, or concrete cleaning visit.
Free estimates, straightforward pricing, no pressure.
Also cleaning: Concrete Cleaning · House Washing