10 Best Cleaner For Trex Deck 2025 in the United States

Wet & Forget Moss, Mold, Mildew, & Algae Stain Remover Concentrate is a liquid cleaner designed for outdoor surfaces including decks, concrete, siding, and roofs. It’s ideal for Trex decks since it doesn’t require scrubbing, rinsing, or pressure washing, making it gentle on composite materials. You mix it with water and spray on a dry surface, then simply wait for rain and wind to naturally wash away moss, algae, and mildew stains. The big plus is its ease of use—no hard work or special equipment needed—and it can keep surfaces clean for up to a year.

The product works gradually; light green stains may clear in 1-2 weeks, but tougher black or old stains could take several months, which might be frustrating if you want quick results. It’s fragrance-free and considered environmentally friendly, relying on gentle ingredients without harsh chemicals. One consideration is that you need dry, cool weather to apply it properly and no rain for a few hours afterward, which means planning ahead.

While it’s safe for wood and composite decks, patience is key since it cleans gradually rather than instantly. For those seeking a low-effort, long-lasting solution that won’t damage a Trex deck, Wet & Forget is a solid choice, especially if you’re not in a hurry and prefer an environmentally mindful product.

The Simple Green 13005CT is a concentrated industrial cleaner and degreaser that works well on various surfaces, including those similar to TREX deck material. Its strength lies in removing tough dirt, grease, and stains, which can be helpful if your deck has heavy grime or stubborn spots. Since it’s a concentrated liquid, you can dilute it to match the cleaning task, making it cost-effective and versatile. The application is flexible—you can use it by hand or with cleaning machines like pressure washers or scrubbers, which might be useful for larger decks.

The cleaner is biodegradable and recognized by the EPA's Safer Choice Program, indicating it’s safer for the environment compared to harsh chemical cleaners. It also has a mild sassafras scent, which some may find pleasant. However, as an industrial-strength degreaser, it might be stronger than needed for regular TREX deck maintenance, and overuse or improper dilution could affect the decking surface or nearby plants. The product is liquid, which makes it easy to apply but requires some care to measure and dilute properly.

If you prefer a ready-to-use cleaner or something specifically designed for composite decking, this might feel a bit more heavy-duty than necessary. Simple Green 13005CT serves as a powerful, eco-friendlier option for deep cleaning TREX decks, especially when dealing with tough grime, but casual or frequent cleaning might call for a gentler alternative.

The Oxy Solve House and Siding Pressure Washer Cleaner is a liquid concentrate designed to clean various types of outdoor siding, including vinyl, aluminum, wood, brick, and stucco. It effectively removes stains caused by mold, mildew, algae, and moss, making it suitable for keeping Trex decks and similar surfaces looking fresh. The main cleaning power comes from peroxide, which breaks down grime without using harsh chemicals, resulting in a safer and more environmentally friendly option.

This non-toxic and unscented formula reduces the risk of irritation and is preferable to traditional cleaners that contain strong chemicals. Being a concentrate, it can cover a large area—up to 6,400 square feet when used with a pressure washer—allowing for efficient cleaning. Application requires a pressure washer, so some familiarity or equipment is needed, but this method generally provides a quicker and more thorough cleaning compared to scrubbing by hand.

Users have rated the product positively for its effectiveness and ease of use. It is specifically designed for siding and deck materials and may not be suitable for delicate surfaces. This cleaner is well-suited for homeowners seeking an environmentally safer and powerful solution to remove mold and mildew stains on outdoor deck materials like Trex, provided they have access to a pressure washer for application.