How to Clean Trex Composite Decking?

Trex and other composite decking materials are prized for their low maintenance, but “low maintenance” does not mean “no maintenance.” To keep the wood-plastic blend looking like new and to prevent the surface from becoming slippery, a regular cleaning routine is essential.

Quick Answer: Mild Soap and Soft Brushes Are Enough

The most effective way to clean a Trex deck is a simple combination of warm, soapy water (using a mild dish soap like Dawn) and a soft-bristled scrub brush. This gentle approach removes most dirt, pollen, and food spills without compromising the protective “cap” or shell of the board.

Why Trex doesn’t need harsh cleaners

Unlike traditional wood, Trex is engineered with a high-performance shell that resists fading, staining, and scratching. Harsh chemicals or acidic cleaners can actually eat away at this protective layer or cause permanent discoloration. Because the material is non-porous, dirt stays on the surface, making heavy-duty solvents unnecessary.

Step-by-Step Trex Deck Cleaning

1. Sweeping debris

Start by removing all furniture and rugs. Use a broom to sweep away loose leaves, pine needles, and dirt. Pay special attention to the gaps between the boards; clearing these gaps ensures proper drainage and airflow, which prevents moisture from trapped debris from rotting the substructure.

2. Soap and water scrub

Mix warm water and mild dish soap in a bucket. Apply the soapy water to a section of the deck and scrub using a soft-bristled brush. Scrub in the direction of the grain pattern to lift dirt out of the embossed textures. For stubborn spots like bird droppings or dried mud, let the soapy water sit for 5–10 minutes before scrubbing.

3. Rinsing properly

Rinse each section thoroughly with a standard garden hose. It is vital to wash away all soap residue; if left to dry, soap can create a dull film that actually attracts more dirt.

Removing Mold and Mildew from Composite Decks

Oxygen bleach vs household cleaners

If you notice green or black spotting, you likely have mold or mildew feeding on surface biofilm (like pollen or spilled soda).

• Oxygen Bleach: Products like OxiClean or specialized composite deck cleaners containing sodium percarbonate are best. They kill mold spores without bleaching the color out of your boards.
• Avoid Chlorine Bleach: Never use standard laundry bleach. It is too harsh for the composite shell and can damage any surrounding landscaping or grass.

Preventing slippery buildup

Mold and mildew make composite decks incredibly slippery when wet. To prevent this, clean your deck at least once in the spring and once in the autumn. Keeping the deck free of organic “food” (pollen and leaves) is the best way to keep it slip-resistant.

What to Avoid on Composite Decking

Pressure washers

Trex explicitly recommends against high-pressure washing. A pressure washer used at close range can “etch” the surface or cause the composite material to delaminate. If you must use one, keep it below 1500 PSI and use a wide fan tip at least 12 inches away from the surface.

Abrasive scrubbers

Never use metal scouring pads, wire brushes, or sanding blocks. These will permanently scratch the protective shell, voiding your warranty and creating areas where dirt can become permanently embedded.

FAQs

Can you pressure wash Trex decking?

It is not recommended. While it might seem faster, the risk of permanent “wand marks” or surface damage is high. A garden hose with a spray nozzle provides plenty of pressure for most cleaning needs.

How often should composite decks be cleaned?

A thorough cleaning twice a year (spring and fall) is standard. However, if your deck is under heavy tree cover or near a pool, you may need to sweep it weekly and do a light soapy wash every 3 months.

Do professionals clean composite decks?

Yes. Professional exterior cleaners often offer soft-washing services. This uses low-pressure pumps and biodegradable surfactants to sanitize the deck safely. This is a great option for large multi-level decks or those with heavy mold infestations.

Want your deck to look brand new without the weekend of hard labor? Our soft-wash specialists understand the unique chemistry of composite materials. We provide deep cleaning that protects your warranty and your home’s curb appeal. Call us today for a professional deck refresh!