How to Clean Trex Decking: Composite Deck Maintenance

Trex composite decking offers the beauty of natural wood with a fraction of the upkeep. Made from 95% recycled materials, eco-friendly, highly durable, and resists rot, mold, mildew, fading, and stains. While the upfront cost is more than a traditional wooden deck, its 25–50-year lifespan makes it a smart, long-term investment.

Knowing how to clean composite decking is key. Whether it's pollen, grease, foot traffic, or dirt, using the right cleaning method preserves your deck’s appearance and extends its lifespan.

Using improper methods or cleaning products can damage your deck. Make sure to follow Trex’s recommend cleaning guidelines. We will show you the basics, common problems, and pro tips to help you avoid expensive mistakes.

Before You Clean: Identify Your Trex Deck Type

Before you clean, determine which type of Trex decking you have. Older and newer models have different cleaning methods. Older Trex decking material, like the Accents® and Origins® products, have a wood-plastic core made of 50% wood.

Older decking board lack the protective shell found on newer Trex decking, making it more prone to mold, mildew, and stains. To restore their appearance safely, you’ll need to use gentler techniques and take extra care during cleaning.

What You Will Need to Clean Your Trex Deck.

Let’s gather what you need to clean your Trex deck the right way. When deep cleaning your composite uncapped Trex deck (older product), use specialized cleaners like Corte-Clean®. Eco-friendly, safe for pets and plants and restores its clean look.

Early-Generation Trex (Uncapped)	High-Performance Trex (Transcend®, Enhance®, Select®)
Soft-bristle scrub brush (non-metal)	Soft-bristle scrub brush (non-metal)
Garden hose with a nozzle	Garden hose with a nozzle
Warm water mixed with a small amount of dish soap	Warm water mixed with a small amount of dish soap
Pump sprayer or a bucket	Pressure washer with a fan tip nozzle (Seasonal use)

Step-by-Step: Best Way to Clean Decking

Step 1: Remove all items from your deck and thoroughly sweep to remove loose debris such as leaves, dirt, and dust.

Step 2: Use a garden hose to rinse the deck to remove surface dust and loosen dirt for easier scrubbing.

Step 3: Mix mild dish soap with warm water in a bucket.

Step 4: Use a soft-bristle brush and scrub toward the grain. Focus on stained areas.

Step 5: Rinse with clean water when removing dirt, soap, and residue. Ensure to rinse the cleaning solution off completely.

Step 6: Dry your deck with a cotton cloth or a leaf blower.

✅ Expert Tips for Cleaning Trex Decking:

• Always rinse thoroughly with clean water to prevent residue buildup.

• Avoid using harsh detergents, ammonia, or chlorine bleach.

• Spot-test any cleaner on a small, hidden area first.

• To remove stain from composite deck boards is to act quickly

Here are the most common Trex decking issues and solutions for both older and newer generations, so you can quickly find what you need.

Common Issue	Older Trex (Uncapped)	Newer Trex (Transcend®, Enhance®, Select®)
Oil or Grease	Rinse with hot water. Then use a composite-safe degreaser (Corte Clean).	Composite deck cleaner. Clean within 7 days to prevent discoloration.
Snow and Ice	Use calcium chloride or rock salt to melt the ice and a plastic shovel.	Use calcium chloride or rock salt to melt the ice and a plastic shovel.
Mold & Mildew	Mold and mildew thrive where moisture and debris build up. Just sweep and rinse regularly to keep this from happening. Use warm water with soap, hose, and a soft bristle brush.	Use warm water with soap, hose, and a soft bristle brush.
Dirt & Debris	Soap, warm water, and soft-bristle brush.	Soap, warm water, and soft-bristle brush.
Tannin (Leaf Stains)	Neutralize black stains from red oak with oxalic acid.	Usually not an issue; Oxalic Acid if needed.
Hard Water Deposits		Rinse with white vinegar. Dry with a towel or blower. Use a brightener if needed.

Oil, grease, and other spills can cause long-term discoloration and void your warranty if not cleaned promptly!

Pressure Wash Composite Deck Safely (Without Causing Damage) 

Use pressure washing for deep cleaning in spring and fall. This works well on high-performance Trex decking like Trex Signature®, Transcend®, Enhance®, and Select®.

If your deck has mud, mildew, mold or dirt and grime that soap and water can't clean, pressure washing can help. However, you must do it correctly. If you’re not careful, a pressure washer can mess up the surface, expose the wood fibers, and void your warranty.

Important: Trex does not recommend using a power washer on early-generation decking products. Using high pressure can damage the surface, expose wood fibers, and make your deck more likely to stain or grow mold.

Follow these guidelines to pressure-wash safely:

·       Use a 40° fan tip nozzle - never a pinpoint or turbo nozzle.

·       PSI should never exceed 3100 PSI and at a minimum of 8 – 12 inches from the surface of the deck. To be safe stick around to 2100 PSI range.

·       Only pressure wash when you need to - don’t make it part of your regular cleaning routine.

Why a sodium hypochlorite deck (bleach) cleaner is not safe for composite decking.

Refrain from using bleach, as it can cause more harm than good. Even though it might seem like a quick fix, Trex warns against it - especially anything like oxygen bleach or chlorine bleach.

While bleach may appear to remove surface-level mold and mildew, it doesn’t penetrate deep enough to eliminate the mold at its roots. As bleach evaporates, it leaves behind moisture, which can further promote mold growth.

However, the risks extend beyond that. Bleach can also cause:

• Fiber degradation

• Surface fading and discoloration

• Long-term damage, especially to early-generation Trex decking

  
  

Even with newer capped Trex products, repeated bleach exposure may lead to staining and surface degradation.

For safer alternatives, use a composite deck cleaner like Corte-Clean® or use mild dish soap with warm water and a soft scrub brush. They are gentle and effective. While it might be tempting in tough cases, bleach is simply not worth the potential damage.

Trex decks are low maintenance, they aren't maintenance-free!

Proper maintenance preserves your Trex deck’s beauty and performance for decades. Determine which type of Trex decking you have, watch for common issues, and stay away from harsh cleaners. Routine care prevents stains, mold, and surface damage. Use composite-safe cleaners, soft brushes, and gentle methods like low-pressure washing when necessary.

Decks hold up differently over time, and how well yours lasts often depends on the quality of the installation and how you maintain it. If you’re unsure where to start, or if your current deck is beyond DIY help, consider working with a professional. A trusted deck builder can ensure you get the most out of your investment.

FAQ:

1.       Can I clean my deck with bleach?

Trex advises against the use of bleach on Trex or other composite decking. Bleach can cause permanent damage, like discoloration, fading, and breaking down the material. Use a composite-safe cleaner made for Trex decking to lift stains and keep your deck looking its best.

2.       How frequently should you clean your Trex deck?

Clean your Trex deck at least twice a year - typically during the spring and fall seasons. How often you clean your Trex deck depends on things like foot traffic, nearby trees, and how humid it gets. Heavy traffic or areas with frequent mold or mildew growth may require more frequent cleaning.

3.       What options are there for homemade composite deck cleaner?

While DIY cleaners may seem appealing, experts usually do not advise using them for composite decking. They can cause damage or leave residues, better to use a safe cleaning solution, like Corte Clean®, made to clean your Trex deck. This solution will keep your deck safe and in good condition.

4. How can I remove stubborn stains from my Trex deck?

Stubborn stains such as oil, grease, and tannin (from leaves) can be tough to remove but are manageable. For oil and grease, immediately clean with hot water and a composite-safe degreaser like Corte Clean. If you have dark stains from leaves, treat them with oxalic acid. Be sure to test a small area first and follow manufacturer instructions for optimal results.