7 Best Chemical Roof Cleaners 2025 in the United States

The Wet & Forget Outdoor Moss, Mold, Mildew, & Algae Stain Remover is a versatile chemical cleaner designed for a wide range of outdoor surfaces, including roofs. One of its main strengths is the new & improved nozzle that attaches to a garden hose, allowing you to spray up to 30 feet high, which is particularly useful for hard-to-reach areas.

The product's application is straightforward: spray on a dry, cool day and let it work over time with natural elements like wind and rain – no rinsing required. However, the time it takes to see results can vary significantly. While green stains may disappear within a couple of weeks, more stubborn black stains could take several months, and long-established stains might need up to a year to fully clean. This extended timeline might be a drawback for those looking for quick results.

Safety-wise, the cleaner is bleach-free and non-acidic, making it safer for use around plants and animals if proper precautions are taken. However, it’s advised to keep it away from bodies of water and to flush plants with water before and after application. With a coverage of up to 2,000 square feet per bottle, it offers good value, but heavily stained or porous surfaces may absorb more product, reducing its effective coverage.

The cleaner is ideal for homeowners looking for a long-term solution to moss, mold, mildew, and algae stains on various surfaces, including roofs, driveways, and decks. It is not suitable for those needing an immediate cleaning solution.

Wet & Forget Outdoor Moss, Mold, Mildew, & Algae Stain Remover is a versatile cleaner designed to tackle various outdoor stains on multiple surfaces, including roofing materials. The product is ready to use and comes with a high-capacity trigger sprayer, making it convenient for application. One of its notable strengths is the ease of use—no scrubbing, rinsing, or pressure washing required; you simply spray it on and let it work over time with wind and rain. This makes it suitable for users looking for a low-effort solution to cleaning their roofs and other outdoor surfaces.

The cleaner’s effectiveness varies: lighter stains can be removed within a few weeks, while heavier, long-established stains may take several months to clear up. This might be a downside for users needing quick results. Safety-wise, the product is bleach-free and non-acidic, reducing the risk of damaging surfaces and making it safer for use around plants, although caution is advised near water sources. Additionally, its environmental impact is mitigated by the recommendation to use it away from lakes, ponds, rivers, and streams.

Compatibility with various materials, including concrete, canvas, and upholstery, is a plus, although users should ensure it is suitable for their specific roofing material before application. The cleaner has an unlimited shelf life and is capable of treating 60 - 180 square feet, but heavy stained and porous surfaces will absorb more product, potentially requiring a larger quantity. Wet & Forget is an effective, user-friendly chemical roof cleaner ideal for those who prefer a hands-off approach, but it may require patience for the most stubborn stains.

The Wet & Forget Moss, Mold, Mildew, & Algae Stain Remover is a versatile concentrate outdoor cleaner designed to tackle stains on various hard, sealed non-porous surfaces, including roofs, driveways, patios, and more. One of its major strengths is the ease of use, as it requires no scrubbing or rinsing—just apply it and wait for nature to do the rest. This can be a big time-saver for users who have large areas to clean.

The product is also bleach-free and non-acidic, making it safer for use around plants when proper precautions are taken, such as flushing plants with water before and after application. However, it is essential to use it away from bodies of water to minimize environmental impact. The mixture ratio is straightforward: dilute one part of the concentrate with five parts water and apply using a garden sprayer.

It is effective over time, with green stains typically clearing up within 1-2 weeks, while more stubborn black stains can take several months to disappear, which may require patience from the user. Long-established stains may take up to a year, so it might not be suitable for those seeking immediate results. Coverage is another strong point, as one bottle can treat between 375 to 1,125 square feet, though heavily stained or porous surfaces will require more product. This product is excellent for those looking for a low-effort cleaning solution with long-term effectiveness, but it may not be ideal for users needing rapid results.