How to Clean a Deck and Treat Stains


Want to know how to clean a deck? It’s easier than you think. It’s also an essential part of protecting your deck and making it last longer.

That’s because wood, being a porous substance, expands and contracts as temperatures vary. Such expansion allows dirt and grime to work their way into the wood over time.

If ignored long enough, your deck will never look clean and can begin to rot and warp more quickly.

Why You Should Clean Your Deck

How to Clean a Deck

Your Deck Affects Your Home’s Value

An outdoor deck dramatically improves the beauty and value of your home, but only if it is in good shape.

Replacing a deck costs roughly $7,000 — a number that potential buyers will take into account if you decide to sell. Even if you’re not thinking about selling your home, that’s a significant expense you probably want to avoid.

Fortunately, you can extend the life of your deck to 20 years or more if you care for it properly.

Neglected Decks are Unsightly

If left uncared for, a deck will develop permanent stains, cracked and splintered wood, and even mold and mildew. That’s not surprising considering they’re exposed to spring rains, summer’s heat, damp Autumn leaves, and winter’s snow.

Neglected Decks are Dangerous, Too

Rotting decks have led to thousands of injuries and multiple deaths. That’s because they’re susceptible to dry rot, something homeowners are unlikely to notice if they ignore their deck. Fortunately, with regular cleaning, you’ll know if your deck is starting to have problems.

How To Clean A Deck

Sweep away noticeable dirt and debris weekly. Then, to keep your deck in good shape, give it a thorough surface cleaning every season.

You will need:

  • A broom
  • Tarps to cover items below the deck
  • Bucket
  • Stiff scrub brush
  • Garden hose
  • Oxygenated bleach (like Oxyclean or Biokleen)
  • Power washer (optional)

Inspect and Sweep

1. Remove everything from the deck. This includes chairs, planters, grills, toys, etc. If you can’t remove it all, you’ll have to work in two parts, moving things to one side of the deck while you work on the other.

2. Inspect the structure. Grab your broom and clean the exterior walls of the house where the deck attaches to it. Inspect the flashing and ledger where your deck is connected to your home. If you notice screws that have worked loose or any signs of rot, contact a licensed contractor immediately to repair it.

3. Sweep. Use the broom on your deck railing, where cobwebs often build up, then sweep the top of the deck. If you can get beneath it, also clean the underside to eliminate debris that will collect moisture.

Treat Stains

Stains need to be dealt with before they become permanent.

1. Spread tarps. Unless your deck sits directly above a concrete patio, you’ll want to use the tarps to protect items below your deck and any nearby plantings.

2. Make this DIY deck-cleaning solution. Add 1 cup of oxygenated bleach to 2 gallons of hot water. Working in sections, spread the cleaner on your deck and allow it to sit for 5 minutes. You may see it bubble a bit as it tackles the stains. Use the scrub brush to scour visible stains then rinse the area and move onto the next. Repeat this on the rails, stairs, etc.

3. Rinse thoroughly. It’s vital to get all of the oxygen bleach off of your deck, so rinse it repeatedly. Rinse the tarps, too.

4. Let it dry. Don’t put anything back on your deck until it is thoroughly dry. Damp wood is fragile, so moving heavy furniture or grills can gouge your wood, and putting things on wet wood will cause mold.

Optional Power Wash

If you’re going to power wash your deck, do it in late Spring to scour away the grit that winter’s snow and rain leaves behind. It’s best to do this on a warm, sunny day with low humidity to speed drying time.

1. Clear and sweep it first. Before power washing, perform the steps above to inspect and clean your deck.

2. Lower pressure is better. A power washer can make a weathered deck look like new as it blasts away grime and discoloration. Too intense of pressure can damage your deck, though, so keep the setting under 1500 pounds per square inch.

3. Keep the nozzle moving. Even a 1500 lbs/psi setting can damage soft or composite wood if you’re not careful, so don’t aim the power washer at any one spot for long. Use overlapping long, sweeping strokes starting at the point where the deck meets your home and working your way outward.

4. Don’t get too close. Keep the pressure washer’s nozzle at least three feet from the deck surface and work in the direction of the wood grain. To clean railings, turn the pressure down to 1000 lbs/psi and work from at least three feet away as you spray them in overlapping quick vertical strokes.

5. Let it dry for at least two days. Pressure washing saturates wood more deeply than a hose does, so your deck needs longer to dry. To speed the drying process and prevent splintering, use a clean broom to sweep away any standing water.

6. Inspect again. Once dry, check and fix any loose screws or hammer in any popped nails then return deck furnishings to their places, and you’re ready to enjoy your outdoor space again.

More Outdoor Home Maintenance Tasks:


  1. So I totally stripped and stained my deck last summer . All I need isn’t I wash off winters grime. Do I need to apply any kind of clear sealer or does the sealer I have good enough ?

    1. Katie Berry says:

      Your sealer from last year should be okay. The pros recommend reapplying sealer every couple of years.

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