Pressure washing a wood deck can completely transform the look of your outdoor living space. Over time, dirt, mildew, and grime can build up on your deck’s surface, making it appear dull, dirty, and dated. A thorough pressure washing cleans your wood deck deeply to restore its beauty and give it a like-new appearance.

With the right equipment, technique, and preparation, you can pressure wash your wood deck properly without damaging the wood. Follow this guide to learn everything you need to know to successfully pressure wash a wood deck yourself.

Gather the Necessary Supplies

Pressure washing requires some specialized equipment that you may need to rent or purchase. Here is the essential gear you need:

Pressure Washer

Obviously, you need a pressure washer. For deck cleaning, a standard electric pressure washer with around 2000 PSI should have enough power to do the job effectively. Gas pressure washers also work if you have access to one.

Make sure the washer has a variable pressure setting so you can adjust the PSI. The pressure should not exceed 3000 PSI for wood cleaning.

Surface Cleaner

A surface cleaner attachment for your pressure washer is highly recommended when cleaning any horizontal surface like a deck. Surface cleaners have rotating jets that distribute the spray over a wider area. This allows you to clean the deck faster and more evenly.

Cleaning Solution

You’ll need a cleaning solution designed for pressure washing wood decks. Look for a cleaner that contains sodium hypochlorite (also known as bleach) to help remove mold, mildew, and graying on the deck boards.

Deck cleaners that contain sodium hydroxide are too harsh for wood and should be avoided. Always follow the cleaner manufacturer’s dilution instructions.

Tip: Some pressure washer surface cleaner attachments have onboard soap injectors that automatically apply and dilute the detergent. This can be a convenient option that helps ensure you use the correct soap concentration.

Safety Gear

Pressure washing is effectively blasting surfaces with high-powered water. So wearing proper protective gear is a must:

Eye protection – Safety glasses or goggles to protect your eyes from debris.
Gloves – Rubber gloves to protect your hands and improve your grip.
Long sleeves/pants – Keep your skin covered to avoid abrasions.
Closed toe shoes – Prevent injury if you drop the wand on your feet.
Face mask – For protection from inhaling spray mist.

Inspect and Prep the Deck

Before pressure washing, take some time to assess the deck’s condition and make preparations:

Clear the Deck

Remove everything from the deck – furniture, plants, rugs, grill, etc. It’s impossible to properly pressure wash underneath objects.

Check between deck board gaps for small items like children’s toys that could hinder cleaning. Removing everything helps you access the entire deck surface.

Check for Damage

Inspect the deck boards and structure closely before cleaning. Look for cracked, warped, missing, or rotted boards that need replacement or repair.

Examine railings, posts, and steps for problems. Identify any weak points so you can avoid focusing the pressure washer on them.

Make all necessary repairs before power washing so water does not seep under damaged boards and cause further issues.

Secure Surrounding Areas

The high-pressure spray can easily damage siding, windows, plants, and other items near the deck. To prevent this:

Cover windows and doors near the cleaning area with plastic sheeting. Tape it securely.
Relocate nearby plants and lawn decor until the deck is dry.
Use tarps and drop cloths to protect patios, walkways, and gardens below the deck. Weigh them down with bricks so they don’t blow around.
Turn off all exterior outlets on the house to prevent electrical issues from water intrusion.

Sweep the Deck

Give the deck a good sweep first to remove surface-level dirt and debris like leaves. This allows the pressure washer to focus on the grime stuck on the wood instead of wasting energy blasting what you can sweep away.

Pay extra attention to corners and tight areas that accumulate dirt.

Adjust the Pressure Washer Settings

The key to safely pressure washing wood is using the appropriate PSI. Too strong of pressure can damage the soft porous fibers of the wood. Follow these tips:

Start on the lowest pressure setting, around 500-1000 PSI.
Slowly increase the pressure until you find the cleaning “sweet spot.” For weathered wood, this is typically 1500-2000 PSI. Newer wood may need less.
Use a narrow 15-25 degree nozzle versus a wide fan nozzle. Narrow nozzles concentrate the pressure in a smaller area for removing stubborn spots.
Keep the nozzle 6-12 inches from the wood’s surface. Get too close and you may etch the wood.
If colored stains or paints are peeling from the wood, reduce the pressure. You want to clean, not strip the deck boards.
Occasionally move your hand across the spray to test the pressure. If it stings your skin, it’s too high for wood.

Adjust accordingly if you notice the pressure damaging or gouging the wood. The goal is power washing the deck thoroughly without marring the surface. Pay attention to find the optimal balance.

Apply the Wood Deck Cleaning Detergent

With the proper pressure washer settings, you can now apply your cleaning solution:

Make sure the detergent is compatible with wood surfaces. Follow the manufacturer’s dilution ratio – usually 4-8 ounces per gallon of water.
Apply the diluted solution liberally across the entire deck using a pump sprayer. Let it sit for 5-10 minutes. This allows time for the cleaner to start breaking down built-up grime. But don’t let it dry completely.
If your surface cleaner has a soap application system, fill it with properly diluted cleaner instead. Apply the solution as you pressure wash.
Mist deck stairs by hand using a standard spray bottle filled with the cleaning solution. The surface cleaner won’t effectively coat the vertical risers.

Allowing the detergent time to work accelerates the cleaning process so you achieve better results. The soap helps suspend and wash away dirt instead of grinding it into the wood surface.

Pressure Wash the Deck

Now comes the rewarding part – blasting away all the built-up gunk and seeing your beautiful wood appear. Follow these steps for best results:

Start pressure washing where your water/electrical source is located. Slowly work your way out from there so you don’t tangle the hose or cord.
Follow the wood grain as you spray. Avoid spraying across the grain which can rough up the wood fibers.
Use long, steady, overlapping passes to ensure full coverage. Position your body so you are spraying away from yourself.
Make additional slow passes on stubborn areas but don’t concentrate in one spot too long. This can damage the wood.
Rinse deck stairs vertically using an up and down motion. Take precautions on slippery wet steps.
Periodically stop to reapply the cleaning solution to areas that need it. Let it soak in several minutes before continuing.
Focus the pressure spray on a small area at a time. Avoid letting the wood dry before you can rinse off all the cleaner.
Thoroughly rinse the entire deck with just the pressure washer to remove all remaining detergent. The wood lightens as it gets cleaner.
After the main deck is done, use a towel to wipe down railings, posts, and spindles by hand. The surface cleaner won’t effectively clean narrow pieces.
Allow the deck to fully dry before replacing any furniture, rugs, or decorations.

Take your time and be thorough to get the best results from your pressure washing session. Patience and the proper technique allow you to deeply clean the wood while protecting its integrity.

Useful Tips for Pressure Washing a Wood Deck

Follow these additional pointers to get the most out of pressure washing your deck:

Work in manageable sections, about 50-100 square feet at a time. It makes it easier to apply and rinse off detergent before it dries.
Wear spiked deck shoes for safety since the surface is slippery when wet. Take slow, careful steps.
Move potted plants onto a dolly to easily shift them on and off the deck as needed.
Use an oscillating sprinkler to lightly pre-wet the deck before power washing. This prevents the wood from soaking up water too quickly before the cleaner can act.
Consider an eco-friendly cleaning solution if concerned about chemical usage and runoff. Look for biodegradable, non-toxic options.
Allow at least 2-3 days of sunny, breezy weather for full drying time before sealing or staining.
Wear knee pads if you have to kneel on the wet deck at any point during cleaning.

FAQs About Pressure Washing Wood Decks

Still have some questions about the process? Here are answers to frequently asked questions:

Should you pressure wash a deck before or after staining?

Pressure wash the deck first to thoroughly clean and open the pores of the wood. This allows new stain to better penetrate. Then let the deck dry fully before applying stain.

Does pressure washing get rid of mold and mildew?

Yes, pressure washing combined with a bleach-based detergent helps eliminate mold and mildew that grow on damp wood over time. Follow detergent dwell times to allow the solution time to kill growths.

How long after pressure washing can I stain my deck?

Let the deck dry for 2-3 sunny days after power washing before applying stain. The wood needs to return to a moisture content below 15% so stain absorbs properly.

Can too much pressure damage my deck?

High pressure over 2500 PSI can damage wood fibers, splinter boards, and peel paints/stains. Use 1500-2000 PSI and test in an inconspicuous spot first. Adjust pressure down if needed.

How do I get into small spaces when pressure washing?

Use a fan-tip nozzle for tight areas like spindles or behind railings. Or spot treat with a stiff scrub brush and detergent before rinsing. Avoid excessive pressure on confined spaces.

Is it better to pressure wash parallel or perpendicular to the deck boards?

Go parallel with the wood grain. This follows the direction of the wood fibers to avoid lifting the grain. Perpendicular spraying risks damaging and scraping the deck boards.

Maintain That Like-New Deck Look

Once you’ve successfully pressure washed your wood deck, follow proper maintenance to keep the fresh appearance. Here are some tips:

Allow the deck wood to fully dry between pressure washing or rain before sealing or staining. Wet wood prevents penetration.
Re-coat the deck with new stain every 1-2 years to protect the wood and prevent graying. Spot treat as needed between full treatments.
Sweep debris like leaves regularly and hose down lightly to prevent buildup. Avoid excessive moisture between full pressure washing.
Inspect for any developing wood damage annually. Make repairs quickly to prevent further deterioration.
Consider covering the deck with furniture covers or storage bins when not in use to shield it from sun and rain exposure.
For winter maintenance, give the deck a final pressure wash and stain touch up in early fall when temperatures are milder.

Keeping up on simple maintenance tasks throughout the seasons prevents the buildup of dirt, mold, and damage that necessitates extensive cleaning. Consistent care keeps your wood deck looking as pristine as the day you first power washed it.

Final Thoughts on How to Pressure Wash Wood Decks

Reviving a tired, dirty wood deck with a thorough pressure washing provides amazing results. Follow proper pressure settings, apply deck cleaning detergent, methodically wash the surface, and allow full drying time. The outcome is a freshly cleaned, brightened deck ready to use and enjoy again.

Just be sure to prep properly and take precautions against spraying too closely or using too much pressure. This avoids permanently damaging the integrity of the wood. Patience and the right techniques make all the difference.

Pressure washing is a satisfying do-it-yourself project that restores life to your outdoor space. Properly maintaining that renewed wood deck also ensures you maximize the time between intensive cleanings. A little deck care goes a long way.

So grab your pressure washer and get ready to tackle that deck. In just an afternoon, you can utterly transform your outdoor living area and create an inviting space for relaxing outdoors. Here’s to a beautiful bright deck ready for making new summertime memories!

How to Pressure Wash a Wood Deck