10 Best Composite Deck Cleaners 2025 in the United States

The 30 SECONDS Outdoor Cleaner 2 Pack with Hose End Sprayer is designed to quickly remove stains caused by algae, mold, mildew, and moss from various outdoor surfaces including vinyl siding, wood decks, concrete, brick, and more. Its strong cleaning power makes it effective for composite decks that often suffer from organic stains.

The product stands out for its ease of use—simply spray on and rinse off with a hose, eliminating the need for pressure washing or scrubbing. It is also safe for your lawn, trees, and shrubs when used as directed, which is a big plus for maintaining your outdoor landscaping. The hose-end sprayer attachment makes application straightforward and reduces mess.

In terms of compatibility, it works well on a wide range of materials commonly found in outdoor spaces, so it’s quite versatile. The formula comes in a ready-to-use spray form, which means no mixing is necessary, though this might be less concentrated compared to some heavy-duty cleaners that require dilution. This cleaner is a convenient and safe choice for homeowners looking to maintain composite decks and other outdoor surfaces with minimal effort.

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.

Wet & Forget Outdoor Stain Remover is designed to clean composite decks and other outdoor surfaces by gradually breaking down moss, mold, mildew, and algae stains without scrubbing. Its cleaning power is gentle and works over time, typically removing green stains within a couple of weeks, but tougher black or long-standing stains may take several months or even up to a year. This slow action means it’s great for people who prefer a low-effort solution, but it’s not ideal if you need immediate results.

The product is safe to use since it’s bleach-free and non-acidic, reducing the risk of damage to composite decking materials. Its hose-end applicator with a long 30-foot spray range and fan tip makes applying the cleaner easy and convenient, covering large areas without direct contact. Because it’s a liquid concentrate, one bottle can treat up to 2,000 square feet, though heavily stained or porous surfaces might need more product.

Another plus is that it requires no rinsing after application, saving time and effort, but you do need to apply it on a dry day with moderate temperatures and no rain expected for a few hours. One minor downside is that the product leaves no residue, so repeat applications may be necessary for tough stains, and it should be applied carefully to avoid nearby water bodies. This cleaner is well suited for homeowners looking for a safe, hands-off way to maintain composite decks and outdoor surfaces over time rather than quick spot cleaning.