How to Pressure Wash a Deck

Pressure washing your deck can remove years of wear and tear in just a few hours. This tutorial will walk you through the process, with detailed instructions for both wood and composite decks (plus optional instructions for staining after).

Wood deck cleaned with a pressure washer

Tools and materials

Besides a pressure washer, you’ll need a few other tools and materials to clean your deck. You may need everything on the list below, or you may just need some things depending on the condition of your deck, whether it’s wood or composite, etc.

  • Pressure washer. You need a decent amount of pressure to clean wood, but you don’t need as much for composite. Use 2,000-3,000 PSI for wood, or 1,500-2,000 PSI for composite.
  • Cleaning solution. You can get the job done without a deck cleaner, but it’s better to use one. Choose a product based on your conditions (if you need to remove mold, old stain, etc.).
  • Push broom. It’s important to clear the surface before pressure washing. Use a push broom if you have one, otherwise any broom (or even a leaf blower) will work.
  • Safety gear. It’s important to wear safety gear (PPE) when pressure washing. Use safety glasses, gloves and hearing protection (if you’re using a gas-powered model).
  • Deck brush. If you need to remove mold, mildew, algae or old stain, you may want a deck brush to scrub the surface. Use stiff bristles for wood, or soft for composite.
  • Brightening solution. If your deck has faded over time, you may want a brightener to restore its natural color. Choose one based on your material (wood or composite).
  • Plastic sheeting. If there’s anything near your deck that shouldn’t get wet, you may want plastic sheeting for cover. Use heavy-duty sheeting, if possible.
  • Garden sprayer. If your cleaning solution isn’t safe for pressure washers (if it contains bleach or any other corrosive chemicals), you’ll need a garden sprayer.
  • Sander, stain, applicator. If you want to stain your deck after pressure washing, you’ll need a few gallons of stain, an applicator (pad, roller, etc.) and a sander (60/80-grit sandpaper for wood, or 220/240-grit for composite).
Wood deck before and after pressure washing

Instructions

If this is your first time using a pressure washer, read our guide on how to use a pressure washer to learn the basics. Then, follow the instructions below to pressure wash your deck (each step includes what to do for wood or composite).

Step 1: Prepare deck

Remove any objects that are blocking the deck (furniture, pottery, etc.), then use your plastic sheeting to cover anything that can’t be moved (doors, plants, etc.). Once the surface is clear, use your push broom to sweep away any loose dirt or debris.

Step 2: Set up pressure washer

Figure out where to set up your pressure washer (ideally, somewhere out of the way but close enough to reach every part of the deck), then connect your garden hose, high pressure hose and spray gun. Turn on your water supply, but don’t start your pressure washer yet.

Step 3: Prepare cleaner

Prepare your cleaning solution following the manufacturer’s instructions, then fill your pressure washer (some models have an onboard detergent tank, others have a siphon tube that you put directly in your solution), or fill your garden sprayer if you have to use one. Now, start your pressure washer.

Step 4: Apply cleaner

Connect the 65° nozzle (usually black), or use your garden sprayer, and spray the cleaning solution onto the deck. If you have a deck brush, use it to scrub the surface, otherwise let the solution soak for a few minutes.

Step 5: Rinse deck

Switch to the 25° nozzle (usually green) for wood, or the 40° nozzle (usually white) for composite, and rinse the cleaning solution from the deck. Work one or two boards at a time, rinsing in the direction of the grain, and make sure you don’t spray too close to cause any damage.

Step 6: Apply brightener

If you bought a brightening solution, use it now following the same instructions as steps 3-5: prepare it, apply it, then rinse it.

Step 7: Finish up

Take down your plastic sheeting, put away your equipment and make sure you properly dispose of any leftover cleaning solution (for those who used chemicals). Wait at least 24 hours for the deck to dry before enjoying it again (or before staining).

Step 8: Staining

Use your sander (with the recommended sandpaper for wood or composite) to sand the deck, then use your push broom to sweep away the dust. Prepare your stain following the manufacturer’s instructions, then use your applicator to spread the stain onto the deck. Work one or two boards at a time, brushing in the direction of the grain, and make sure you apply the recommended number of coats (two coats is standard, but again, follow the manufacturer’s instructions).

Frequently asked questions

The most common questions about pressure washing a deck are answered below. For other questions, you can reach out to us at any time. If you have a question about a specific product, you may need to contact the manufacturer.

How much does it cost to pressure wash a deck?

The average cost to pressure wash a deck is between $0.50-0.75 per square foot, which includes labor and supplies. This comes out to $150-225 for the average backyard deck. Keep in mind, this doesn’t include stain. Expect an additional $0.25-0.50 per square foot for staining.

How long should you wait to stain your deck after pressure washing?

You need to wait until the deck is dry before staining (usually 24-48 hours, but it varies). Some brands say their stains can be applied within a few hours, but you’ll still have to sand the deck before staining and that can only be done once it’s dry, so expect to wait at least a day.

Can a pressure washer damage a deck?

Pressure washers can damage anything, especially soft surfaces like wood and composite. With that said, it’s easy to prevent damage: simply use the right nozzle and don’t spray too close to the surface or hold the stream in one place for too long.