10 Best Composite Deck Cleaners 2025 in the United States

The 30 Seconds Outdoor Cleaner is designed to quickly remove moss, algae, mold, and mildew stains from various outdoor surfaces including composite decks, vinyl siding, patios, and fences. Its cleaning power is strong enough to tackle organic growth effectively, which is great if you want a fresh, clean look without harsh scrubbing or pressure washing.

The product is safe to use around lawns, trees, and shrubs when you follow the directions, so you don’t have to worry about damaging your landscaping. Application is simple — you just attach the hose-end sprayer to the bottle and spray the affected area, then rinse off. This method is convenient and saves time compared to using a pressure washer or scrubbing by hand. It covers about 900 square feet per bottle, so it’s suitable for medium to large outdoor cleaning jobs.

Compatibility-wise, it works well on a variety of surfaces including wood, concrete, brick, plastic, and vinyl, making it versatile for many outdoor cleaning needs. The concentration is balanced to provide strong cleaning without leaving harmful residue, supported by the safety claims indicating it rinses off cleanly. The product comes in bottled form with a hose attachment, so you need access to water and a hose for best results. This cleaner is a practical choice for homeowners looking for an easy, safe way to remove organic stains from composite decks and other outdoor surfaces without needing special equipment.

The 30 SECONDS Pro Mold and Mildew Stain Remover is designed to quickly brighten and clean mold and mildew stains without the need for scrubbing, which is great if you want to avoid hard physical work. The formula is twice as strong as the original version, making it effective on tough stains commonly found on composite decks and other surfaces. It is suitable for a wide range of materials including wood, vinyl siding, concrete, and even indoor spots like bathroom tiles, making it versatile for both outdoor and indoor use.

The product comes ready to use in a refill bottle, which simplifies application and avoids extra mixing steps. Users can expect noticeable results almost immediately, which is helpful for quick cleanups. Being a ready-to-use concentrate, it should not leave heavy residue.

This cleaner is well-suited for homeowners needing an efficient, no-scrub solution to maintain composite decks and similar surfaces, especially if mold and mildew stains are a recurring problem.

The RMR-86 Instant Mold and Mildew Stain Remover Spray is designed to quickly tackle stubborn mold and mildew stains without the need for scrubbing, making it convenient for users who want an easy cleaning solution. It’s a ready-to-use liquid spray that works instantly to remove discoloration, which is especially helpful for deep stains that often appear on composite decks and other outdoor surfaces.

One of its strengths is versatility—it’s safe to use on multiple surfaces like wood, vinyl siding, concrete, and brick, so you can rely on it in various areas around your home. Because it’s a professional-strength formula, proper ventilation and protective gear are recommended during use to ensure safety. The spray has a fresh scent and doesn’t leave behind noticeable residue after cleaning, which means less rinsing and cleanup afterward.

Although it’s not specifically labeled just for composite decks, its compatibility with common deck materials makes it a suitable choice for deck maintenance. The main drawback is the need for caution during application due to its strong chemical nature, so it might not be ideal for those looking for a gentle or eco-friendly cleaner. For fast, effective mold and mildew stain removal with minimal effort, this product is a strong option.