How to Safely Pressure Wash a Deck in Everett, WA
If you own a home in Everett, Lake Stevens, or anywhere else in Snohomish County, you know how beautiful our spring and summer seasons can be. Unfortunately, you also know what our wet, shady winters leave behind. By the time April and May roll around, many local decks, patios, and walkways are covered in an unsightly layer of slippery green algae and mildew.
Not only does this green buildup ruin your outdoor aesthetic, but it also creates a major slipping hazard when wet. Over time, wood-decaying fungi can even rot your expensive cedar or pressure-treated boards.
Naturally, most homeowners want to blast this grime away quickly. A power washer seems like the ultimate weekend tool for the job. However, if you are not careful, an afternoon of DIY cleaning can permanently scar your wood. Let’s look at exactly how to safely pressure wash a deck in Everett without causing expensive damage.
The Danger of Too Much Pressure
Wood is a relatively soft, fibrous material. Cedar, which is highly popular for Northwest decks due to its natural rot resistance, is particularly soft.
The biggest mistake DIY enthusiasts make is treating a wood deck like a concrete driveway. They rent a high-powered unit from a local home improvement store, slap on a narrow, high-pressure nozzle, and hold the wand just inches from the surface.
When you apply excessive water pressure to soft wood, you don’t just blast away the mildew—you rip apart the wood fibers. This results in:
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Wood Gouging: Permanent, ugly track marks carved across the boards.
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Splintering and Fuzzing: Ripping up the soft grain, which makes the wood feel fuzzy and guarantees splinters for bare feet.
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Deep Water Injection: Forcing water deep into the core of the wood, which traps moisture inside and actually accelerates rot.
Once wood fibers are blown out by high pressure, the damage cannot be easily undone. It often requires heavy, aggressive sanding or total board replacement.
The Professional Strategy: Soft Washing Over High Pressure
Professional exterior cleaners rely on a technique called soft washing. Instead of using raw, destructive water pressure to mechanically rip the mold off the wood, professionals use specialized, biodegradable cleaning solutions to safely dissolve the organic growth at its roots.
Here is how to approach the project safely if you want a clean finish without the damage:
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Apply a Dedicated Deck Cleaner: Use a specialized deck cleaner designed to break down algae, mold, and mildew. Let the solution sit on the wood for 10 to 15 minutes. It should stay damp so the ingredients can lift the organic stains gently.
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Pick the Right Spray Tip: Never use the red 0-degree nozzle or the yellow 15-degree nozzle on wood. Instead, choose a wide, gentle fan tip—typically the green 25-degree or white 40-degree tip.
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Adjust the Pressure Setting: Keep your machine’s pressure low, ideally under 1,000 to 1,200 PSI (Pounds per Square Inch) for soft woods like cedar or pine.
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Maintain Your Distance and Sweep: Hold the pressure washing wand at least 12 to 18 inches away from the deck surface. Move the wand in smooth, continuous sweeping motions along the length of the boards, following the natural grain. Never stop moving the wand or trigger it while pointing directly down at a single spot.
Preparing for Paint or Stain
Once your deck is clean and free of green mold, it needs to dry completely before you can seal, stain, or paint it. Applying a finish over damp wood will cause the product to bubble and peel away almost immediately. In the Pacific Northwest, it typically takes a few consecutive days of dry, warm weather for a washed deck to be completely ready for its protective finish coating.
If your deck looks dull after cleaning, a light, professional sanding can flatten any raised grain and open up the wood pores, allowing fresh stain to penetrate deeply and last much longer.
Let the Professionals Handle the Grime
Don’t spend your limited sunny weekends dealing with loud rental equipment, messy chemicals, and the constant fear of ruining your outdoor living space.
At MGR Painting, LLC, Victor and our dedicated team offer professional pressure washing and exterior cleaning services engineered specifically for Northwest homes. We know exactly how to balance gentle cleaning solutions with the correct water pressure to make your wood surfaces look brand new again.
Explore our full suite of professional exterior services on the MGR Painting, LLC. When you are ready to get rid of that slippery green mildew safely, check out our Contact Page to drop us a line or call for a free estimate!