10 Best Composite Deck Cleaners 2025 in the United States

The Wet & Forget Outdoor Moss, Mold, Mildew, & Algae Stain Remover is an effective composite-deck cleaner that excels in its cleaning power, capable of removing green and black stains without requiring scrubbing, rinsing, or pressure washing. This makes it highly convenient for users looking for hassle-free cleaning solutions. It covers multiple surfaces, including porch steps, headstones, fountains, and even upholstery, showcasing its versatility.

The attached high-capacity trigger sprayer ensures easy application, and the product works over time with natural elements like wind and rain to clean surfaces, which means less effort on the user's part. However, it's important to note that while green stains may clean up relatively quickly (within 1-2 weeks), more stubborn stains can take several months to fully disappear, which might be a drawback for those seeking immediate results. Safety-wise, the product is bleach-free and non-acidic, which is a plus, but users need to be cautious around water bodies and plants, ensuring to spray 100 feet away from lakes, ponds, rivers, and streams and to flush plants with water before and after application to avoid harm.

The product's unlimited shelf life is a significant advantage, and it treats a substantial area of 60 - 180 square feet depending on the stain and surface. While it is unscented, which might appeal to those sensitive to strong smells, users should be aware that it requires application on dry days when rain is not expected within 4-5 hours and when temperatures are above 32°F to avoid rapid evaporation and ensure effectiveness. This product is ideal for homeowners who want a low-maintenance, long-term solution for outdoor cleaning, although patience is required for the best results.

The Wash Safe Industries WS-SC-1G Clear Spray and Clean Composite Deck Cleaner is a 1-gallon organic cleaner designed specifically for decks. In terms of cleaning power, it effectively removes dirt and grime, making it a good choice for maintaining the appearance of your outdoor space. Its safety profile is commendable as it is organic, which means it's less likely to harm your deck or the surrounding environment.

The application method is straightforward since it comes in a spray form, allowing for easy and even distribution over the deck surface. Compatibility-wise, it is specifically made for composite decks, ensuring it works well without causing damage. The concentration is strong enough for effective cleaning but might require dilution depending on the level of dirt and staining.

One notable advantage is that it doesn’t leave a noticeable residue, which means you won’t have to worry about slippery surfaces after cleaning. On the downside, its organic nature might make it slightly less potent against extremely tough stains compared to chemical-based cleaners. Additionally, with a weight of 9 pounds and relatively large package dimensions, it may be a bit cumbersome to handle and store. This product is ideal for homeowners looking for a safe, easy-to-use cleaner that’s friendly to the environment and effective for regular maintenance of composite decks.

The 30 SECONDS Pro Mold and Mildew Stain Remover is a potent cleaner designed to tackle tough mold and mildew stains on a variety of surfaces, including composite decks. One of its standout features is its impressive cleaning power, boasting a formula that is twice as strong as the standard 30 SECONDS Outdoor Cleaner. This means it can handle the most stubborn stains without the need for scrubbing, saving you both time and effort.

The product is ready to use, which simplifies the application process—just spray it on and watch the stains disappear. Additionally, it works instantly, offering brighter results right away, which is a big plus for those needing quick results. The cleaner is also versatile, suitable for both indoor and outdoor use, covering surfaces like drywall, wood, vinyl siding, concrete floors, and even kitchen and bathroom tiles and grout.

However, there are a few potential drawbacks. While it's effective, its strong formula might pose safety concerns, especially for those with sensitive skin or respiratory conditions, so proper precautions like wearing gloves and masks are advisable. The product is scented, which might be an issue for people sensitive to smells. Moreover, the packaging is quite bulky, with a weight of 36.3 pounds for a 4-pack, which might be cumbersome for some users to handle. Lastly, it’s important to note that while the product claims to leave no residue, ensuring thorough rinsing is necessary to achieve the best results. This cleaner is ideal for those who need a powerful, ready-to-use solution for tough mold and mildew stains on various surfaces, including composite decks.