Composite decking has become super popular with homeowners in Canada because it’s durable, low-maintenance, and looks great. But just like any outdoor surface, it still needs regular cleaning to keep it looking its best and lasting longer. In this guide, we’ll walk you through how to clean your composite deck, the best cleaning methods, and some handy tips to make sure your deck stays in top shape all year round.

Why Regular Cleaning is Essential for Composite Decking

Composite decking is built to resist weathering, stains, and mold, but that doesn’t mean it’s totally maintenance-free. Over time, dirt, grime, and organic debris can build up, causing discoloration or even damage if left unchecked. Regular cleaning helps:

• Keep your deck looking fresh
• Prevent mold and mildew
• Extend the life of your deck
• Maintain a safe, slip-resistant surface

With the right cleaning techniques, keeping your composite deck in good shape can be easy.

Tools and Supplies You’ll Need

Before starting to clean your composite deck, make sure you’ve got these tools and supplies ready:

• A soft-bristle brush or broom
• A garden hose with a spray nozzle
• Mild dish soap or a composite deck cleaner
• A bucket of warm water
• A plastic spatula (to scrape off any stubborn debris)

Optional: A pressure washer (but use it carefully!) Having everything on hand will make the cleaning process way smoother and more efficient.

Step-by-Step Guide: Best Way To Clean Composite Deck

1. Clear the Deck Surface

First things first, move any furniture, planters, or outdoor decor off the deck. Then, grab your soft-bristle broom and sweep away all the loose dirt, leaves, and debris. This step clears the surface and makes sure your deck is prepped for a deep clean!

2. Rinse the Deck

Now, grab your garden hose and give the deck a good rinse. Let the water flow steadily to wash away all the loose dirt, dust, and light debris on the surface. This step helps soften up the grime and gets the deck ready for a deeper clean. Just make sure to use a gentle stream of water—no need for high pressure, as that can push dirt deeper into the grooves, making it tougher to clean later. Take your time and make sure you hit every area evenly so the deck is all set for scrubbing.

3. Prepare the Cleaning Solution

Fill a bucket with warm water and add a small amount of mild dish soap or a composite deck cleaner (TimberTech has some great options). If you’re using a specialized cleaner, be sure to follow the instructions on the label for best results. Just a heads up—stay away from harsh chemicals like bleach. They can damage the deck, cause discoloration, and might even mess with your manufacturer’s warranty. This gentle cleaning method will keep your deck looking great and well-maintained without any risk of damage.

4. Scrub the Deck

To clean the deck, dip your soft-bristle brush into the cleaning solution, but make sure it’s not soaking wet. Gently scrub along the wood grain to lift off the dirt without damaging the surface. Focus on spots with stains or dirt buildup, and give those a little extra attention. If you’ve got debris stuck between the boards, use a plastic spatula to scrape it out gently—just be careful not to scratch the wood.

5. Rinse Thoroughly

Once you’re done scrubbing, grab the garden hose again and rinse the deck thoroughly to wash away any leftover soap. It’s super important to get rid of all the soap residue, as any that’s left behind can attract dirt and make the deck look dull over time. If you spot any stubborn spots, don’t be shy—go over them again with the scrub brush and rinse once more until the deck looks fresh and clean.

6. Dry the Deck

Make sure to let the deck dry completely before putting any furniture or decorations back. Giving it time to air dry helps prevent water spots and ensures the surface is safe to walk on. It’s key to let it dry naturally so the wood can breathe and stay in good condition. This easy step keeps your deck looking great and lasting longer, making it a safer and more enjoyable space for everyone to hang out.

Best Practices for Cleaning Composite Deck 

Here are some simple tips to keep your composite decking looking awesome:

1. Clean up spills ASAP: Even though composite decks are pretty resistant to stains, it’s still best to wipe up things like wine, grease, or food right away. This keeps any stains from setting in over time.
2. Skip the metal tools: Metal tools like steel brushes or scrapers can scratch up your deck. Stick to plastic or non-abrasive tools to keep the surface smooth and undamaged.
3. Test new cleaners first: Before using a new cleaner all over your deck, test it on a small, hidden area. That way, you’ll know it won’t mess with the colour or damage the surface.
4. Sweep regularly: Dirt, leaves, and other debris can pile up fast. Sweeping at least once a week helps prevent buildup and keeps your deck looking fresh all year long.

Follow these easy steps, and your deck will stay looking great for years to come!

Using a Pressure Washer: Is it Safe?

Pressure washers can be a great tool for cleaning composite decks, but you’ve got to be careful. Use a pressure washer with a fan tip and set it to no more than 3100 PSI. Keep the nozzle at least 8 inches away from the deck to avoid damaging the surface. Here’s how to use it safely:

1. Rinse the deck using the pressure washer, working in the direction of the grain.
2. Don’t spray directly into seams or gaps.
3. Rinse thoroughly to make sure all the soap or cleaning solution is gone.

Dealing with Stubborn Stains and Mildew

If you’ve got tough stains or mildew, here’s how to tackle them:

For Stains:

• Make a paste of baking soda and water.
• Apply it to the stain and gently scrub with a soft brush.
• Rinse well with water.

For Mildew:

• Use a composite deck cleaner made for mold and mildew.
• Apply it to the affected areas and let it sit for 10-15 minutes.
• Scrub gently and rinse thoroughly.

This should help keep your deck looking clean and fresh.

Seasonal Maintenance Tips

Your composite decking needs different care throughout the year. Here’s how to adjust your cleaning routine by season:

Spring:

• Give your deck a deep clean to remove dirt and grime from the winter months.
• Check for any damage or wear that may have occurred during the colder season.

Summer:

• Sweep regularly to get rid of pollen, dust, and other outdoor debris.
• Clean up spills right away to avoid stains from setting.

Fall:

• Clear leaves and other organic debris to prevent mold and mildew from building up.
• Do a thorough cleaning before winter hits to keep things fresh.

Winter:

• Skip the metal shovels for snow removal—use plastic ones instead to avoid damage.
• For ice, use a calcium chloride-based deicer instead of salt to protect the deck.

These seasonal steps will help keep your deck in top shape year-round.

Common Mistakes to Avoid

To keep your composite deck looking great, avoid these common missteps:

• Using abrasive cleaners: Harsh chemicals can strip away the deck’s protective coating, leaving it vulnerable.
• Overusing a pressure washer: Too much pressure can damage the surface of your deck, so use it carefully.
• Neglecting regular cleaning: If you don’t clean your deck often, dirt and mold can build up and make it harder to clean later.
• Ignoring manufacturer’s guidelines: Always stick to the care instructions specific to your deck’s brand to avoid any issues.

Conclusion: The Best Way to Clean Composite Decking

Cleaning your composite decking doesn’t have to be a hassle. By following this guide, you’ll know exactly how to clean it properly and keep it looking amazing. Just remember to use the right tools, follow seasonal maintenance tips, and steer clear of common mistakes. With regular care, your deck will stay looking fresh and beautiful for years.