Can You Pressure Wash Composite Decking?

Tom Gaffey
by Tom Gaffey

Composite decking is a real game changer in the deck-building game. It has all sorts of benefits that often make it a superior choice to the classic wooden decks, not to mention no more splinters in your feet. There are lots of reasons to go with composite decking, from the fact that it’s highly customizable, to its low maintenance needs and its ability to repel dirt. Composite decking is even easy to clean. But when you do need to clean it, can you use a pressure washer?

Using a pressure washer on composite decking is not recommended. These washers can damage composite decking, leaving etching marks and even puncturing the decking itself. A medium-bristled nylon brush and soapy water works best. If you decide to pressure wash composite decking, be sure to keep a safe distance, and use no more than 1,500 PSI in order to prevent unnecessary marks and damage.

If you have a pressure washer, you might be itching to use it on your composite deck. While it is certainly possible, there are several reasons you should think twice before using it on composite decking. If you do decide to use a pressure washer on this type of decking, however, there are several tips listed below that can help you do so safely, without damaging your composite deck.

Reasons Not To Use Pressure Washer On Composite Deck

It might seem crazy and outright unfair that most professionals say not to use pressure washers on composite decking. While it is not outright forbidden, there is a good reason that you should think twice before reaching for your pressure washer. Here are a few reasons you should consider cleaning your composite deck with something other than a pressure washer.

Composite Decks Are Softer Than You Think

Composite decks have a firm and permanent feel, but they are not invincible. They are a mixture of wooden fibers, nylon, and laminate, but they are not as pliable as wood or metal. They also show damage and scratches fairly easily, which is why a strong pressure washing is a big red flag.

Etched And Scratched Surfaces

One danger with pressure washing your composite deck is if you are not careful, you can easily scratch and etch your composite deck. This can happen very quickly and in an instant, if you carelessly forget to turn it to its lowest setting. What is worst about this is these scratches can cheapen the overall look of the deck. This turns your beautiful versatile composite deck into a bit of an eyesore, and costs lots of money to fix.

Compromises Finish And Lead To Sun Damage

Even if you do not notice any immediate damage after pressure washing your deck, there may still be problems. Pressure washing composite decks can potentially strip away at the protective seal on the material. This helps prevent sun damage and protects the material over time. If you strip this off your deck can suffer sun and weather damage much sooner than it would have without pressure washing it.

Tips If Using Pressure Washer On Composite Decking

Use A Fan Tip. A fan tip can help mute the pressure a bit and can help you still do a focused cleaning on the deck. When using the fan tip, it is still good to go at an angle. This will prevent the pressure from being stronger than it needs to be.

Keep A Safe Distance. Allow yourself as much distance as possible between the pressure washer and the deck itself. As a rule, do not allow the pressure washer closer than 12 inches from the deck at any time. Ideally, you should try to allow even more than 12 inches of space whenever possible.

Go With The Wood Grain, Not Against it. The idea here is that you are using the fan tip to clean with the grain. This way, if for some reason there were to be any scratch marks, they would go along with the grain, and not perpendicular to it. It is also an effective way to loosen up the dirt hidden in the grains.

Use The Lowest Power Setting. One of the best ways to minimize or completely prevent damaging your composite deck when pressure washing is to use the lowest pressure possible. This means using your pressure washers lowest pressure setting. This will be different based on the pressure washer. Regardless, be sure you never use anything higher than 1,500 PSI. Anything higher is a recipe for damage.

Steps To Best Clean Your Composite Deck

The best way to clean your composite deck is fairly simple, and requires very little equipment. It involves a scrub brush, dish soap, water, and following these steps carefully.

Step One: Remove All Furniture And Items From Deck

The first step to cleaning your deck is to clear it. First, carefully remove any of the heavier furniture you have. Be careful not to drag it and cause scratches. Then remove any rugs, flower pots, and anything else at all that rests on the deck. This will allow you to clean it in its entirety.

Step Two: Remove Debris And Sweep The Area

Once you have removed all the obstacles, you are ready to begin cleaning. Before you wash, however, you need to sweep up and clear away any debris. First, remove any larger pieces, like branches and twigs. Then give the whole deck a good sweep. This will prepare the deck for the next step.

Step Three: Rinse The Composite Deck

As you would a car, rinse the deck with your garden hose. This will get the deck wet, which helps with scrubbing. It will also assist in loosening up any caked-on or dried dirt and grime.

Step Four: Prepare Solution and Tools

In a 5-gallon bucket, combine water with dish soap. You can also use specialty soap or cleaning solution if your deck calls for it/you purchased it. You will need a soft to medium bristled scrub brush/broom. Work the head of the brush in the solution and get it good and mixed. Now you are ready to scrub the deck.

Step Five: Scrub The Deck

Use the soapy nylon brush to scrub down decking. Make sure you dunk the brush regularly so soapy water is working its way through the entire deck. When scrubbing, be sure to go along the grain, not against it. This will make for smoother scrubbing and better results.

Step Six: Rinse And Inspect

Use your outdoor garden hose to rinse off the dirty soapy water. Make sure you rinse the area thoroughly so no soap residue remains on the deck. Let the area dry. Once everything is dry, inspect the deck. If you notice any small dirty areas, give them a quick spot clean with your brush and more soapy water, and then repeat the rinsing process.

Once all is cleaned and dry you can put all your furniture, rugs and plants back on your composite deck, and enjoy.

Find The Right Cleaning Solution And Tools

In addition to following all the steps to preparing and cleaning your composite deck, you must also have the right materials and tools. In general, dish soap tends to be highly effective at cleaning composite decks. You can also purchase earth-friendly soaps to make sure none of your surrounding plants will suffer any toxic spillage. Your deck may have come with specific cleaning instructions that require a certain type of cleaner. If that is the case, be sure to follow those instructions.

When it comes to a scrub brush, the key is to find a brush that has enough strength to scrub a surface, but is soft enough to never scratch the composite decking. A soft to medium strength scrub broom brush should work well. If you have any questions, consult a professional at the hardware store.

Remember To Clean Between Gaps In The Composite Deck

In addition to following the above steps to best clean your deck, it is important you remember to clean every nook and cranny. This includes making sure you clean between the gaps of the composite deck as well. It may require some additional elbow grease, but cleaning between the planks on your composite deck can increase its longevity.

Think of your decking like your teeth, in that flossing is as important as brushing. Most professionals suggest cleaning in all these nooks and crannies one or two times a year. So while the task may seem a bit tedious, it only needs to be done once in a blue moon.

Wrapping Up How To Best Clean Composite Decking

The preferred way to clean your composite decking does not involve using a pressure washer. In fact, the best method is to simply use a dish soap and warm water mixture (or specific cleaning solution and water) and a soft or medium bristled nylon brush. This tried and true scrubbing method is both effective and easy on the material. Be sure to follow the proper cleaning steps above and you are sure to have a clean and healthy deck for years to come.

Tom Gaffey
Tom Gaffey

Tom Gaffey is an expert writer who currently resides in Washington D.C. Tom has a passion for real estate and home improvement writing, as well as travel and lifestyle writing. He lived the last twelve years in Hawaii where he worked closely with luxury resorts and event planners, mastering his knowledge of aesthetics and luxury products. This is where he found his passion for home improvement and a keen interest in DIY projects. Currently, Tom resides in Washington D.C, and also working on his debut fiction novel.

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