How to Clean a Painted Deck in 8 Steps

Before you get to scrubbing, you’ll want to remove anything on, under, or near the deck. No one likes accidentally damaging planters or having to toss out patio seating, so pay special attention to the following tips: 

• Remove any outdoor furniture, toys, grills, and other portable items.

• If there are plants nearby, you may wish to cover ones that are sensitive to soap. Most plants will not be hurt by the small amount of soap if you wet them with the hose before you start. 

• If you use the space beneath your deck for storage, remove items that might get damaged from soap.

While you could use a normal floor sponge or mop, the gaps, slivers, and ends of boards will tear it up fast. Save yourself the trouble by using a push-broom instead. Look for one that has a lot of fine bristles—not the widely-spaced and stiff ones designed for clearing away dirt and debris from durable surfaces, as these can leave ugly streaks on your deck boards due to incomplete coverage.

Alternatively, you can also use an extension brush for washing cars, though they aren’t as durable and don’t offer as much coverage as your typical push-broom.

Your deck is officially free of obstacles, and now it’s time to prepare the cleaning solution. There are a few soapy mixtures you can use to get your deck in tip-top shape:

DIY Cleaning Solutions

One of the easiest ways to clean a painted deck is to use good ol’ dish soap or laundry detergent, and warm water. Just avoid using vinegar, which can eat away at and deteriorate the paint. If you want to use bleach to clean your deck, be sure to choose oxygen bleach over chlorine bleach, as it’s gentler and less harmful to the environment. You can safely mix oxygen bleach with dish soap to create a cleaning solution, but never, ever mix chlorine bleach and soap together. The combination of chlorine bleach and dish soap can create toxic gasses that lead to illness and potentially death when combined.

Here’s how to create a safe oxygen bleach and dish soap cleaning solution:

• Combine 2 ounces of soap or detergent, 8 ounces of oxygen bleach, and warm water to your one-gallon bucket, filling close to the top.

• Mix well

• Consider using a spray bottle to target badly stained, grimy, or hard-to-reach sections of the deck.

Note: It’s important to note that bleach may stain or damage sensitive types of wood, such as cedar, redwood, cherry, and more. Research the type of wood you have and test the solution in an inconspicuous place prior to using it (like where your grill usually sits).

Store-Bought Cleaning Solutions

There are also gentle all-purpose cleaners designed to clean decks without chipping the paint. Look for solutions that are:

• Ammonia-free

• Bleach-free

• Eco-friendly

• And specifically for painted decks

Get your push broom ready to scrub the deck. You can do this by saturating your brush with the cleaning solution. It should only take a minute or two to get the brush fully drenched with the solution.

Pour soapy water on the deck and let it sit for about 10 minutes. Then, pour the cleaning solution onto the deck’s surface, making sure it gets spread around evenly. The whole deck should be covered with the solution.

Time to get scrubbing.  Lightly work away at the dirt, mold, mildew, and surface stains, working on one deck board at a time. Load up on soapy water frequently so that there is enough to keep it all wet while you scrub. The time it takes to scrub away grime depends on how dirty it is—but prepare for this part to take longer than the other steps.

Use a garden hose with a spray nozzle—not a jet nozzle—to rinse as you go so the dirty water does not sit or dry on the boards, which could dirty and stain all your hard work.

If your deck is super dirty, you might have to go through two cycles of washing and rinsing so it looks its best. After you rinse the deck, let it air-dry completely between wash cycles so that you can see where you need to scrub more.

Also, letting your deck dry after your first cleaning helps keep the paint and wood from getting so saturated that the paint peels.

Tips For Cleaning a Painted Deck

• The dirty water will run down under the deck, so clear out stuff under there first to keep it from damaging any valuables.

• Dirty water that moves down dry siding makes unsightly streaks. Wash away from the house, wet the siding with the hose, and keep the siding wet before rinsing the deck. Then, rinse again immediately afterward to avoid staining any sidings. 

• You may need to clean the siding first before working on the deck, re-rinsing the siding as you go. If water runs down the siding from the deck, keep the siding wet throughout the process so the dirty water does not stick to it, then rinse that again last.

• Avoid pooling water against the side of the house, the ledger board, or the foundation.

• Important warning about bleach: Never mix ammonia with bleach or other household cleaning solutions that contain bleach, as this creates toxic fumes.