Should I Pressure Wash my Deck? What Professionals Say


Cleaning the deck with a pressure washer looks pretty easy – all you do is point and shoot. However, pressure washing your deck without the proper equipment or settings can cause very costly damages. Pressure washers can throw water strong enough to carve into brick or gently enough to remove a few stains and cobwebs. The key to success is finding the right PSI setting to clean your deck without ruining it.

Should I Pressure Wash my Deck?

Generally, cleaning via a pressure washer is much quicker than scrubbing my hand. You can get rid of stains and impurities from the wood, but the high-pressure water from the pressure washer can erode wood. I recommend setting the PSI according to the quality of the wood. For softer wood, the PSI should be around 500, but it can go up to 1200 PSI for harder wood. Along with making sure you use the right PSI, use the proper techniques and nozzle to avoid damaging the wood.

Should I Pressure Wash my Deck? What Professionals Say 1

Throughout this article, you will learn how to use a pressure washer to clean any deck surface safely and effectively through step-by-step instructions. In addition, you will learn what damages power washing can cause and how to avoid them, along with washing before staining and the right time and conditions to pressure wash.

How do you Pressure Wash a Deck Without Damaging it?

Pressure washing a deck without damaging it requires some knowledge about the condition of the surface. As stated earlier, the hardness of wood can determine the PSI used. Along with tools like the size of the nozzle. Using too narrow of a nozzle can splinter the wood. I recommend using a white 40-degree for great results.

Your decks and the area of your house are the most exposed to dirt and moisture and are often neglected. Before washing or sealing the deck, it’s important to eliminate all the stains, mold, and dust. You can do this with simple water, a cleaning solution, or a pressure washer. But even used correctly, a power washer can cause damage. This is why it’s important to follow the steps below to avoid any damage to your deck.

● Step 1: Safety Measures

Before using the pressure washer in any job, always put safety precautions first. Not only can the high water pressures damage the wood, but they can injure the person using it. Wearing protective gear like gloves, safety goggles, rubber shoes, and ear protection can prevent serious injuries.

● Step 2: Prepare the Surrounding Area

Prepare the deck and surrounding area to be power washed. This means covering the plants using tarps or painter’s tape, moving any furniture or fragile items, and cleaning the wood. Applying the cleaner beforehand and leaving it for a few days can protect your wood structure. Similarly, for the grease stains on the deck surface, scrub the wood using the brush after applying cleaner over it.

● Step 3: Choose the Right PSI

For cleaning a deck with a pressure washer, use the lower pressure settings. For example, softwoods like pine and cedar require PSIs of 500 to 600 for proper cleaning. Hardwoods like Teak, Ipe, Iroko, Camaru, Garapa and Balau require 1200 to 1500 PSI.

● Step 4: Choose the Right Nozzle

Choosing the right nozzle also plays an important role in cleaning a deck effectively. Usually, a fan or rotating tip works best for cleaning wood. Apply water pressure 18 inches (no more than 12 inches) from the deck and check water pressure away from people or glass. Since wooden decks are not as strong as concrete or bricks, I recommend using a wide-angle nozzle. For example, the white 45-degrees nozzle or the black 60-degrees nozzle.

● Step 5: The Right Technique

Using the right technique also plays a big role in pressure washing a deck without damaging it. The best technique is to push water across the surface using a sweeping motion with your arms, maintaining at least one foot of space between the deck surface and your nozzle. Move with the wood grain to prevent rippling.

● Step 6: Sand Down any Raised Areas

You might find that pressure washing the deck had caused some areas of the wood to raise. After letting the wood completely dry, use sandpaper to level the wood and sand away the raised areas.

Can Power Washing Damage a Deck?

While, when done correctly, pressure washing should not hurt your deck. Power washing is similar to pressure washing but using hot water. Hot water helps to remove more tough stains. But there are outside variables that can lead to damage. For instance, power washing an already weathered deck could cause the wood to split or splinter or raise the wood grain and cause ripples in your deck. These problems can be fixed by using lower water pressure and sanding your deck afterward.

Washing your deck incorrectly could include using the incorrect PSI, cleaning solution, technique, or nozzle. The same issues – wood splintering, rippling, and mold – can arise with these problems. These problems can be fixed by double-checking your deck’s needs before washing, correcting your technique, and making sure any cleaning solution has dried before washing.

Should you Pressure Wash a Deck Before Staining?

Generally, for a newly installed deck, it’s not necessary to pressure wash it before staining. You can simply clean the surface with a hose and mop before washing it. However, for an old deck, it is necessary to pressure wash it and apply a deck cleaner for a brighter result. Pressure washing and cleaning a deck before staining provide a better look later on.

When should I pressure wash my deck?

It is necessary to pressure wash your deck at least once a year. Being exposed to weather conditions year-long will lead to staining, warping, dirt, and mildew that can damage the wood surface of your deck. But what is the right time?

The answer is simple – you never want to pressure wash your deck when the temperature is below freezing. At this temp, the water in the pump of the pressure washer will start to freeze. Actually, experts say that the perfect temperature is above 52 degrees Fahrenheit when there is no rain. At this temp, water will dry quickly off of the wood.

What PSI is needed to power wash a deck?

To clean a wooden deck, I recommend using the lowest pressure setting that you will find effective. Start from the lowest setting and only increase when you can not remove a tough stain. Use a pressure around 500 to 600 PSI for softwoods like cedar, pine, and California Redwood. And 1200 to 1500 PSI for harder woods like Teak, Ipe, Iroko, Camaru, Garapa and Balau.

Can you use a pressure washer surface cleaner on a wood deck?

In general, I would not recommend using a surface cleaner on a deck. Particular with softwood, it is better to spray with the grain of the wood. That is not possible with a surface cleaner. But as long as the pressure is such that it does not damage the wood, you can use it.

What is the best homemade deck cleaner?

These are some of the best homemade deck cleaner recipes:

● Homemade General Cleaner

The first recipe is for a general cleaner. It uses regular household cleaning items and is easy to make. You need:

  • 1 gallon of warm water
  • 1 cup of laundry detergent (powder)
  • 3/4 cup of oxygen bleach (sodium percarbonate)

Add the ingredients to a bucket, and stir them. When thoroughly mixed, you can pour the mixture on the deck. Let it stay there for 30 min so that it can do its work. Then use your pressure washer to clean the deck. Ensure that you use a low PSI and go with the grain of the wood.

● Homemade Mildew and Algae Remover

This recipe is perfect for removing tough mildew and algae. You need:

  • 1 gallon of water
  • 1 cup of soap. I recommend using an ammonia-free soap.
  • 1 quart of bleach
  • 2 cups of rubbing alcohol

Add the ingredients to a bucket, and stir them. When correctly mixed, pour the mixture on the deck. Let it stay there for half an hour to let the ingredients do their work. You can then use your pressure washer to clean the deck. Ensure that you use a low PSI and go with the grain of the wood.

● Homemade Organic Deck Cleaner

This organic deck cleaner uses vinegar and baking soda. When mixed they react with each other and work together to remove stubborn stains and grease. You need:

  • 1 gallon of water
  • 1 cup of vinegar
  • 1 tablespoon of baking soda
  • 1/2 cup of lemon juice

Add the ingredients to a bucket, and stir them. You will see the vinegar and baking soda react with each other. When thoroughly mixed, pour the mixture on the deck. Let it stay there for half an hour so that it can do its work. Then use your pressure washer to clean the deck. Ensure that you use a low PSI and go with the grain of the wood.

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