How to pressure wash a deck

August 12, 2023

Elerein Yanki

Hi, I am Yanki, the founder of bisonclean.com. I have been in the cleaning equipment field for more than 5 years now, and the purpose of this article is to share with you the knowledge related to cleaning equipment from a Chinese supplier's perspective.

Ideally, you should pressure wash your deck at least once a year to keep the deck surface free from the growth of algae, mold, etc., and other elements that can damage your deck. Such regular maintenance not only enhances the beauty of your outdoor space, but also prolongs the life of your deck.

However, how do you pressure wash a deck? Before you can pressure wash, you need to know how to do it properly, especially when dealing with fragile wood decks. This article will take a closer look at how to pressure wash a deck, and we’ll walk you through the process step-by-step to ensure you get the best results. With regular pressure cleaning, you can ensure your deck is always in tip-top shape, giving you a beautiful, safe outdoor living space.

Why pressure wash your deck?

It’s essential to understand why pressure washing is beneficial before we proceed. Over time, decks accumulate dirt, grime, mold, and other unsightly and potentially damaging elements. If left unchecked, these can cause your deck to deteriorate rapidly, leading to costly repairs or replacements.

Routine pressure cleaning is a critical step in ensuring your deck always stays clean, safe and looking great. By cleaning regularly, you can not only effectively eliminate the build-up of dirt, leaves and other debris between the planks, but also prevent slip hazards and deck rot problems. Trapped leaves and debris not only increase the risk of slipping on the deck, but also absorb moisture, causing rot that can prematurely compromise the deck’s lifespan.

Pressure washing removes dirt and stains, restores color, and prevents rot and decay by eliminating mold and mildew. Regular pressure washing can significantly extend the lifespan of your deck, making it a worthwhile investment for every homeowner.

How many PSI do I need to pressure wash a deck?

When power washing a deck, the PSI (pounds per square inch) required to pressure wash the deck also varies with the type of deck material and the level of cleaning required. As a manufacturer that has been pressure cleaning for over a decade, Elerein offers you some general guidelines for pressure cleaning decks below:

1. Wood decks: For most wood decks, a pressure washer with a PSI range of 1,500 to 2,500 will suffice. Softwood is generally fragile, so when pressure washing a softwood deck, keep the pressure between 1,000 and 1,200 PSI. Pressure above this range may damage or weaken the wood and may cause raised grain. Hardwood floors can generally withstand more stress. When pressure washing hardwood decks, keep it between 1,200 and 1,500 PSI. Remember, whether you have a soft or hardwood deck, make sure to start with a low PSI and gradually increase the pressure to prevent damage to the deck.

2. Concrete or composite deck: If you have a concrete or composite deck, you may need a higher PSI, such as the 2,500 to 3,000 range. These materials can handle higher pressures, but it is still recommended to start with a lower setting and adjust accordingly.

3. Dirt and stain level: The level of dirt, stain and grime on your deck will also affect the PSI you should use. For light cleaning, a lower PSI may be sufficient, while more stubborn stains may require a higher pressure.

The choice of pressure washer nozzle will also affect the effective pressure. The wide-angle nozzle spreads pressure over a larger area for gentler cleaning, while the narrow-angle nozzle focuses pressure on a smaller area for more powerful cleaning. For buyers specifying equipment for deck-maintenance programs, confirming that a unit offers adjustable pressure settings and interchangeable nozzles can help ensure the same machine is suitable across wood, composite, and concrete deck surfaces without requiring separate equipment for each material.

Regardless of the pressure you use, always test on an inconspicuous area of the deck to ensure that the pressure you are using will clean effectively without damaging it. Always follow the manufacturer’s guidelines for your specific pressure washer model and deck material. If you’re not sure which PSI to use, seek advice from professional washer experts. This way, you can achieve excellent results while keeping your deck safe and protected.

Safety first: Precautions to take when pressure washing

Safety should always be a priority when using power tools, including pressure washers. Here are some essential safety tips:

Protective gear: Always wear safety glasses and gloves to protect yourself from debris and high-pressure water spray.
Proper handling: Never point the nozzle at people, animals, or delicate surfaces. The high-pressure water jet can cause injury or damage.
Pressure control: Be careful not to over-pressurize the surface you’re cleaning. This can cause serious damage, especially to wooden decks. Start with a low pressure setting and gradually increase it as necessary.
Aftercare: Thoroughly rinse the surface after cleaning. This removes any residual dirt or debris that could become embedded in the deck material.

Step-by-step guide to pressure washing your deck

Step 1: Prepare the deck area

Good preparation is the key to success. Before you begin, remove all furniture, plant pots, and other objects on the deck. This gives you easy access to the entire deck surface and prevents damage to your belongings.

Next, use a broom to sweep up loose debris. Large debris can clog a pressure washer or scratch a deck when pushed by a high-pressure water jet.

If your deck is heavily soiled or stained, consider using a deck cleaning solution before pressure washing. This helps loosen and break down stubborn dirt and stains, making them easier to remove. Applying a wood-specific or composite decking cleaner and letting it soak for 5-10 minutes softens dirt before rinsing, making the subsequent pressure washing pass more effective.

Step 2: Choose the right pressure washer and accessories

Choose a pressure washer with the correct PSI (pounds per square inch). For most decks, a 1000 to 2000 PSI unit will suffice. Connect the hose and wand to the pressure washer according to the manufacturer’s instructions.

Choose a wide angle nozzle or fan nozzle (25-40 degrees) to avoid damaging the wood. For most decks, a 25 to 40 degree nozzle is ideal. These nozzles provide a broad spray pattern that can effectively clean large areas without causing damage. Use a 25-degree (green) spray tip rather than a 15-degree (yellow) or 0-degree (red) tip, as concentrated sprays can gouge softer woods like cedar and redwood. When operating the wand, hold it at a 25- to 40-degree angle and never perpendicular to the wood, since a steeper angle concentrates pressure and increases the risk of surface damage.

If you are using a deck cleaning solution, attach the soap injector or soap dispenser nozzle at this stage. This will allow you to spread the solution evenly over the deck. Use a low-pressure nozzle to spray the deck cleaner on the deck. Let the cleaner sit for 10-15 minutes, but don’t let it dry.

Step 3: Turn on the pressure washer

Once you’ve connected the appropriate nozzle, you’re ready to turn on your pressure washer. Always start with the low pressure setting, especially if you are new to pressure washing or handling delicate surfaces. You can gradually increase the pressure as needed.

Step 4: Start pressure washing

Now, start pressure washing your deck:

start at one end of the deck and work your way up. Make sure to cover and wash the entire deck.
Use a sweeping motion to distribute the water evenly. Keep the nozzle moving at all times to avoid concentrated pressure in one place for long periods of time.
Hold the pressure washer nozzle 6 to 10 inches from the deck surface. This distance provides optimal cleaning power without the risk of damaging deck materials.
Angle your spraying parallel to the wood grain to remove dirt most efficiently.

Step 5: Rinse and dry deck

After you’re done pressure washing, it’s critical to rinse your deck thoroughly. Use a garden hose to rinse the deck, starting from one end and working your way to the other. This will remove any remaining dirt, debris, or cleaning solutions that may stain or damage the deck.

After rinsing, allow the deck to dry completely and inspect the wood for any signs of damage. Check for chips, deformation or cracks. Then replace the furniture or use the deck. This usually takes 24 to 48 hours, depending on weather conditions.

Additional tips for effective deck pressure washing

Frequency: If your deck is in good condition, pressure washing once a year is usually sufficient. However, if your deck is heavily soiled or stained, more frequent cleaning may be necessary.
Type of deck: Be cautious when pressure washing wooden decks. Too much pressure can damage the wood by causing splintering or gouging. Composite decks, on the other hand, can withstand higher pressure settings.
Railings: Protect railings from high-pressure water by adjusting pressure or spray angle.
Surface cleaner: If you’re using a surface cleaner attachment, be sure to follow the manufacturer’s instructions for best results.

Conclusion

As you complete how to pressure wash a deck, taking the time to follow these systematic steps ensures your outdoor living space remains both pristine and protected for years to come. Proper preparation, correct pressure settings, and regular maintenance not only enhance the natural beauty of the wood but also extend its structural lifespan.

As a leading pressure washer manufacturer, Elerein delivers robust, high-performance cleaning solutions engineered to effortlessly strip away weathered finishes and stubborn grime without damaging delicate wood grain. Partner with us today to equip your inventory with industry-leading pressure washers designed to maximize your market advantage and ensure ultimate customer satisfaction.

FAQs about pressure wash a deck

What are the signs that the water pressure is set too high during the process?

Watch for wood splintering, raised fibers that feel fuzzy to the touch, visible gouge marks, or light-colored streaks where the natural stain has been aggressively stripped away. If you notice any of these signs, immediately back the wand further away from the surface or reduce the pressure setting.