What Pressure Washer Nozzle is Safe For Decks?

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There are many ways to clean a deck, but the most efficient method is with a pressure washer. It is faster and easier than hand scrubbing or garden hose for sure, but you have to use the right nozzle tip. One of the worries people have is that pressure washing might damage the wood surface. However if you use the correct nozzle this will not happen.

Most decks require a 25 degree nozzle (green) for cleaning and removing dirt. For decks that only need light cleaning, a 40 degree (white) pressure washer nozzle is ideal. Apply 500 PSI pressure for soft wood and up to 1200 PSI for hardwood deck surfaces. Pressure wash annually for the best results.

Which Pressure Washer Nozzles are Safe for Decks?

There are many types of pressure washer nozzle tips, but only two are suitable for deck cleaning: the 25 degree and 40 degree nozzles. The 25 degree nozzle is green and the 40 degree nozzle is white.

The following are the most common types of pressure washer nozzles. As you will see, there are good reasons why the other tips must not be used on decks.

Tip: the Bopopo 4000PSI Pressure Washer Tips has the complete set. Whether your needs are for home or for commercial / industrial applications, you will find the tips here.


Red nozzle tips are set at 0 degrees and provide maximum power. The tip strikes water directly on the surface. It does not spray or spread the water out.

There are two reasons why red nozzle tips are never used on decks or almost any residential surface. The blast is so strong and concentrated it will damage the deck. It will also strip off car paint and siding. It is also small (about the size of a quarter) so cleaning will take a long time.


Yellow nozzle tips are 15 degrees and useful for removing dirt on 4x4s. This tip is often used to prep surfaces for painting. But it is not suitable for decks because it is too powerful.


Green (25 degrees) is the most widely used tip for home pressure washing. It is what you will likely use for deck cleaning. At 25 degrees it produces a wide spray and applies enough pressure to remove dirt. However, it is gentle enough on the surface so it does not cause damage.


White nozzle tips are 40 degrees and the gentlest. This is frequently used to wash windows but can also clean decks. However white nozzle tips might be too gentle to remove stubborn dirt. In that case you have to use the green nozzle.

There are other nozzle tips that may come with your pressure washer. The black nozzle is 65 degrees and used for soap cleaning. There are also adjustable nozzles, foam cannon nozzles and rotary nozzles.

Once you have chosen a nozzle you can start the cleaning process. If you want to replace or upgrade the pressure washer spray gun though, there are some things you need to consider.

Can Pressure Washer Nozzles Damage Decks?

Pressure washers can damage deck surfaces if you use the wrong nozzle. But using the correct nozzle will clean any deck without stripping the surface.

Among the potential problems that can occur when you use the wrong pressure washer nozzle are.

Wood splintering. If the nozzle blast is too powerful, the water can lead to wood splinters. This is difficult to repair and makes cleaning harder.

Cracking. Those small wood splinters will get bigger if you keep using the wrong nozzle. Eventually it will lead to cracks on the wood deck surface.

Peel off the surface. Blasting a red nozzle tip on a wood deck can rip off any stain or surface paint you applied. This is another reason why you should only use green or white nozzle tips.

If you use the wrong nozzle, it can cause serious damage not just on wood decks but also car paint and other surfaces. When you pick the right one, these situations can be avoided.

How to Properly Use Pressure Washer Nozzles on Wood Decks

Using a pressure washer is straightforward, but knowing what nozzles to use is the key. For decks and wood surfaces in general, use a 25 or 40 degree nozzle tip.

Once you have chosen the nozzle, keep the PSI level in mind. The good news is the green and white nozzles control the pressure. But for soft wood, keep the PSI around 500-600. For hardwood you can go higher up to 1200. If the dirt is really stuck you might be able to use up to 1500 PSI. Just start with as little pressure as possible and increase slowly if necessary.

Test the Nozzle First

Once you have chosen a nozzle, plug it onto the pressure washer and test it on a small section of the deck. Start at 500 PSI and start cleaning. Increase the PSI until it reaches the cleaning level you need.

If you chose a white nozzle and it is not removing dirt, switch to green. If you are already using a green nozzle, increase the PSI. Do not switch to a yellow nozzle as this will damage the deck.

Start Pressure Washing

Start by pressure washing the railings. Keep the nozzle 6 to 10 inches away and spray from top to bottom. It might require a couple of passes if the railings are very dirty.

Point the spray gun down to the deck. Lower the nozzle, but no more than six inches from the surface. Spray with a sweeping motion while moving your arms laterally. Wash one wood board at a time and overlap each board a little.

The key to pressure washing is be as thorough as possible. Clean each row evenly and as thoroughly as you can.

It might require multiple passes to clean the deck depending on how dirty it is. In some instances you might also have to add a cleaning solution with the water. Do this if the deck is caked with dirt and water is not enough. Follow the instructions that came with the cleaner for its application.

After the deck is clean, wait at least a couple of days before applying any stains or sanding. If there are blemishes, sand the surface and then pressure wash again. When dried, you can apply stains or sealing.

Related Questions

How often can I pressure wash my wood deck?

Clean your deck annually. If you pressure wash too often it could weaken or damage the wood, even with a gentle nozzle. If you wait several years between each cleaning on the other hand, dirt will be very difficult to remove.

Which is more effective for decks, a pressure washer or garden hose?

A pressure washer is more effective than a garden hose. First, garden hoses do not generate enough pressure to remove stubborn dirt. A pressure washer does. As long as you are careful and choose the right nozzle, there will be no damage.

How near the deck surface should the nozzle be when pressure washing?

No more than six inches. Start around 10 inches and go lower if dirt refuses to come off. If you get closes than six inches the force from the nozzle could damage the wood.

Can I pressure wash any type of wood deck?

Most decks are made from natural wood (cedar, pine etc.), vinyl or composite materials. You can pressure wash any of those as long as you use a 25 or 40 degree nozzle.

My pressure washer cannot remove dirt stuck between the wood boards. What should I do?

Use a putty knife to scrape dirt stuck between the boards. You can do this after the first pressure wash. Once you have removed the dirt, pressure wash again.

Why is the nozzle not producing any water?

Check the water pressure if it is too low. Next, inspect the nozzle because it might be clogged. The spray gun trigger might also be damaged so that should be looked into as well.