9 Essential Steps to Clean Composite Decking Like a Pro

Composite decking is beloved for its low-maintenance charm: no more staining and sealing, no more worrying about rot or insect damage, and no more warping and cracking.

Just sweep it off, and you’re ready to host your barbeque!

Still, life happens. Burgers drip grease, trees drop leaves, and dirt accumulates. Every so often, your deck needs a good solid cleaning. 

At Keystone Custom Decks, we aim to help you create your dream outdoor living space. We know it’s difficult to enjoy your deck if it’s filthy, so today, we’re going over a basic step-by-step guide to cleaning your composite decking.

Table of Contents

  • 1
    Step 1⁠: Acquire the Appropriate Tools
  • 2
    Step 2: Clear and Sweep Your Deck
  • 3
    Step 3: Clean the Cracks
  • 4
    Step 4: Hose Down Your Deck
  • 5
    Step 5: Prepare the Cleaning Solution
  • 6
    Step 6: Apply the Cleaning Solution and Scrub Your Deck
  • 7
    Step 7: Thoroughly Rinse the Deck
  • 8
    Step 8: Clean the Stubborn Spots
  • 9
    Step 9: Let it Dry, and Enjoy Your Clean Deck!
  • 10
    Bonus: Five Ways to Stop Procrastinating and Get to Work on Your Deck Cleaning Project

Step 1: Acquire the Appropriate Tools

Do you feel a sense of dread at the very thought of cleaning your deck?

Deck cleaning may feel like a huge chore, but it doesn’t have to be. Often, the difference between a dreaded chore and a doable chore comes down to one factor: do you have the right tools?

As a bare minimum, here are the tools you should have before you attempt to deep-clean your deck:

Other items that you may find helpful include:

Many of these tools are inexpensive but make a huge difference. For example, using a smaller bucket with a larger scrub brush might not seem like a big deal, but it’s frustrating if you can never fully submerge your brush in your bucket. That frustration may make you subconsciously avoid cleaning your deck.

Mini Graphic

With the right tools, this type of chore feels cathartic rather than draining.

Step 2: Clear and Sweep Your Deck

Once you’ve acquired the right tools, it’s time to deep clean your deck! Start by removing all furniture and other loose items, then sweep the deck to remove loose surface dirt, debris, and leaves. 

Alternatively, if you have a lot of leaf buildup, you might find it easier to use a leaf blower for this step.

If you have a large deck and sweeping with an ordinary kitchen broom feels daunting, consider investing in a larger push broom.

Step 3: Clean the Cracks (Optional)

Depending on how your deck boards are spaced, you may have a lot of leaves, small sticks, pebbles, bits of dog food, and random screws wedged in the crevices. 

Unfortunately, a simple deck clean will not displace these items. To clean the cracks, you’ll need to invest in a crevice-cleaning device. Run the device through the cracks to remove debris before proceeding to the next step. 

Remember: if clogged crevices are not an issue on your deck, skip this step and move right along to the next one!

Step 4: Hose Down Your Deck

Use a garden hose with a spray nozzle to rinse the decking boards thoroughly. For now, there’s no need to attempt to remove stains or caked-on debris—focus on a simple rinse to prepare for the next step.

Step 5: Prepare the Cleaning Solution

Fill your bucket or sprayer with water and mild soap. Something simple like Dawn dish soap will work fine, but you can buy soaps specifically formulated for composite decking.

Text Graphic 1 (1)

If you’re unsure of what soap to use, you can Google your specific decking brand to see if the manufacturer has recommended a particular type of soap.

If you’re using a deck cleaner, consult the bottle for instructions on preparing the solution. If you’re using dish soap, fill your bucket or sprayer with warm water and squirt about as much soap in as you would if you were using that water to wash dishes.

Step 6: Apply the Cleaning Solution and Scrub Your Deck

There are two ways to apply the cleaning solution:

  1. You can spray it on the deck, wait 10 or 15 minutes, and then scrub it with the long-handled deck brush, or
  2. You can dip your long-handled deck brush in a bucket of cleaning solution and apply it as you scrub

Ultimately, it comes down to personal preference. The spraying method allows the soap time to penetrate, but if you prefer using a brush and bucket, you can achieve the same effect by brushing the solution on, leaving it for a few minutes, and then scrubbing it again.

If you encounter stubborn stains, don’t worry too much about them at this stage.

Step 7: Thoroughly Rinse the Deck

Using a hose with a sprayer, thoroughly rinse off your decking. Make sure to rinse away all traces of the cleaning solution to prevent residue buildup.

Now, you’ll be able to see much more clearly if dirty spots or stubborn stains haven’t come off yet.

Text Graphic 2 (1)

Step 8: Clean the Stubborn Spots

While the above seven steps should leave your composite decking sparkling clean, they may not be enough to remove some stains or caked-on debris. 

To clean these stubborn spots, you have a couple of options:

The simplest method is to re-apply the cleaning solution, let it sit for a few minutes, and then scrub it with a handheld scrub brush, repeating these steps as many times as necessary to remove the stain. 

Another option is to remove the stains using a pressure washer.

In general, composite decking manufacturers discourage the use of a pressure washer on composite decking since high-pressure water can damage the material. But if you’re the type of person who would much rather attack stains with a pressure washer than a scrub brush, here are some tips for using one without damaging your deck:

  • Check the manufacturer’s guidelines for your composite decking brand and ensure that using a pressure washer will not void your warranty. 
  • Use a pressure washer with an adjustable pressure setting. Start with a lower pressure to test its effect on a small, inconspicuous area of the decking. Don’t exceed 3100 psi.
  • Keep the pressure washer nozzle at least 12 to 18 inches from the decking surface to prevent damage.
  • Use a wide-angle nozzle or a fan tip to disperse the water evenly and reduce the intensity of the stream.
  • Avoid using hot water, as it can soften the composite material and make it more susceptible to damage.
Text Graphic 3 (1)

Step 9: Let it Dry, and Enjoy Your Clean Deck!

Finally, let your deck dry and put all the furniture back in place.

If you choose a warm, sunny day to clean your deck, you can clean it in the morning, let it dry in the afternoon, and it will be usable by evening!

Bonus: Five Ways to Stop Procrastinating and Get to Work on Your Deck Cleaning Project

If you find yourself procrastinating and avoiding the dreaded chore of deck cleaning, here are a few expert tips to get you going.

  1. Invite friends over for a barbeque. Once you know your friends are going to see your filthy deck, you’ll be much more inspired to clean it!
  2. Buy some new deck-cleaning tools. Sometimes, getting to use new tools instead of old, worn-out ones is enough inspiration to help us tackle a dreaded chore.
  3. Ask a friend to help. All you need is a spare long-handled deck brush, and not only will the deck get cleaned twice as fast, but you’ll have a friend to chat with as you work. Return the favor by helping your friend with a home maintenance project.
  4. Play your favorite music, podcast, or audiobook while you work. For extra inspiration, designate your favorite podcast as a “project podcast” that you only listen to while doing chores.
  5. If you’re overwhelmed by the size of the project, break it into manageable chunks. For example, you could gather all your supplies one day, clear and sweep the deck the next day, wash the deck the third day, and clean the stains the fourth day.


We hope you’ve enjoyed this exploration into how you can efficiently and effectively clean your composite decking. At Keystone Custom Decks, our hope is that your deck can be a space you’re proud of, where you can relax or host great parties.

To that end, we’ve written several deck-related blog posts you may be interested in, such as:

If you’re interested in creating the outdoor living space of your dreams, we’d be delighted to help you out! We build:

Get a free estimate today, or give us a call if you’d like to have a meaningful discussion about how we can help you realize your outdoor living dreams.