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Pressure washing is an effective method for cleaning off dirt, dust, and other debris, as well as stripping layers of old stain or paint from the surface of a deck. But before directing a high power spray toward the vulnerable wood, it’s important to learn how to pressure wash a deck the right way. The sheer force produced during a pressure washer cleaning can accidentally damage a deck if the user holds the nozzle too close or uses a pressure cleaning output that is too powerful for wooden deck spray washing.
It’s also helpful to select a targeted cleaner, such as the Ecolab Scientific Clean Wood Deck and Fence Pressure Wash available exclusively at The Home Depot, to create a cleaning solution that helps to remove tough, stuck-on dirt, oil, and grime. Keep reading to discover how to power wash deck boards coated in stain, paint, dust, dirt, and debris in order to clean your deck quickly and effectively.
Tools & Materials
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Before You Begin
One of the main reasons a pressure washer is effective at cleaning a tough, porous material like wood is the powerful spray produced by these tools. That powerful spray is also the reason it’s important to wear protective eyewear, thick boots, and heavy-duty gloves during use.
The strong spray can also knock up pebbles, small rocks, and dirt. Consider covering shrubs, gardens, and air conditioners with a drop cloth before you begin. This will help protect them from the powerful spray and flying debris, and minimize unwanted splashing.
Step 1: Attach the spray nozzle to the pressure washer.
To get the correct angle and water pressure for cleaning the deck, you need to attach a nozzle to the pressure washer. Start with a soap-dispensing nozzle if you are using a cleaning solution or simply the widest nozzle to ensure that the initial water pressure is relatively low. Spray nozzles are typically color-coded to help indicate the spray pattern.
- White indicates that a nozzle sprays at 40 degrees.
- Green indicates that a nozzle sprays at 25 degrees.
- Yellow indicates that a nozzle sprays at 15 degrees.
- Red indicates that a nozzle sprays at 0 degrees.
- Black indicates that a nozzle dispenses soap and significantly restricts the pressure.
Step 2: Connect and turn on the pressure washer.
Connect the pressure washer hose to the pressure washer and turn it on. Make sure that the hose has a clear path to the pressure washer and the area where you will be working so that it doesn’t kink or catch, blocking the flow of water into the pressure washer.
Set the pressure washer to the lowest power setting and pull the trigger to test the current water pressure output. It’s recommended to start in an inconspicuous part of the deck, in case the initial flow of water damages the surface of the wood.
Adjust the distance between the nozzle and the deck, as well as the angle of the spray until the pressure washer is successfully removing dirt without damaging the deck or splashing you.
STEP 3: Add deck cleaning solution to the pressure washer.
A deck cleaning solution—like this highly rated Ecolab Wood Deck and Fence Pressure Wash Concentrate—is a great option to help remove tough, stuck-on oils and grime. Simply mix the cleaner with water according to the package instructions and pour the solution into the dispenser on the pressure washer.
Step 4: Apply the deck cleaning solution.
With the black soap-dispensing nozzle attached to the pressure washer, begin to apply the deck cleaning solution to the deck. Use long, broad strokes with the pressure washer wand to ensure that the cleaning solution reaches the entire deck, including any corners, cracks, or crevices.
After application, allow the cleaner to sit on the wood for about 10 to 20 minutes, or as indicated by the manufacturer’s directions, before swapping in a white or green spray nozzle on your pressure washer.
Step 5: Pressure wash the deck.
The powerful water pressure generated by a pressure washer will do most of the work for you. Your job is to control the water pressure and the aim of the pressure washer wand. Choose a side to start from and begin pressure washing the deck in wide, horizontal swaths.
Once one row is complete, move down and across to pressure wash the next row. Continue working like this until the entire deck is clean. Also, keep in mind that it may take multiple applications of deck cleaning solution or multiple passes with the pressure washer to completely clean the porous surface of a wood deck.
Step 6: Let the deck dry before sanding, staining, or sealing.
Allow the deck to dry before walking on it to prevent bending or warping the wood. The deck can take up to 2 days to fully dry after pressure washing, and it may take longer to dry if it rains. Once the deck is fully dry, you may want to take on an additional project to reduce deck maintenance in the future.
Use a sander to remove any blemishes from the surface of the deck and to sand away any residual chemicals from old stain or paint products. After sanding a wood deck, it’s a good idea to pressure wash the deck again to remove any sand particles before staining or painting. Make sure to let the deck dry after this second washing so that the stain or paint can effectively bond to the wood.
Final Thoughts
While the basic idea of spraying water at the deck to remove dirt and grime may seem harmless, pressure washers generate a significant amount of power and can easily damage wood if not used properly.
They can also hurt exposed skin or sensitive areas of the body, like the eyes, ears, or nose. Avoid aiming the pressure washer near yourself or another person during use. If you or anyone else is sprayed in the eyes with a pressure washer, it’s recommended to seek medical help as soon as possible.
