10 Best Mildew Cleaner For Concrete 2025 in the United States

The 30 SECONDS Outdoor Cleaner is a solid choice for anyone looking to tackle stains caused by organic growth like algae, mold, and mildew on various outdoor surfaces. With its easy application method, you simply spray it onto the affected area and rinse it off, making it a user-friendly option for homeowners who may not be familiar with more complex cleaning methods like pressure washing. The cleaner is effective on a wide range of surfaces including concrete sidewalks, wood decks, and vinyl siding, making it quite versatile for different cleaning needs.

One of the standout features is its safety profile; when used as directed, it is safe for lawns and plants, which is a significant advantage for environmentally conscious users. This means you can clean without worrying about harming your garden or landscaping, making it suitable for those with outdoor spaces.

There are a few drawbacks to consider. While the product is efficient at tackling stains, the effectiveness may vary depending on the severity of the mold and mildew. For particularly stubborn stains, you might need to apply it multiple times or even resort to more aggressive cleaning methods. Additionally, the hose end sprayer can sometimes clog, which may complicate the cleaning process.

The Wet & Forget Outdoor Moss, Mold, Mildew, & Algae Stain Remover is a user-friendly cleaning solution designed specifically for outdoor surfaces, making it an excellent choice for tackling mildew on concrete. One of its standout features is the Xtreme Reach Hose End nozzle, which allows for easy application up to 30 feet away, making it convenient for cleaning hard-to-reach areas like roofs and siding. The product is bleach-free and non-acidic, which is a significant plus for those concerned about environmental safety. Additionally, it’s effective over time, as it cleans with rain and wind, which can be more practical than immediate results for homeowners willing to wait for a thorough clean.

On the downside, the product requires some patience, especially for heavy stains, which can take several months to fully disappear. This might be a drawback for users looking for instant results. Also, applying the cleaner requires specific conditions, such as avoiding hot days and ensuring no rain is forecasted shortly after application, which could limit its usability for some. Its coverage of up to 2,000 square feet is quite generous, but porous surfaces may absorb more product, thus requiring additional applications.

Wet & Forget is ideal for outdoor enthusiasts looking to maintain clean surfaces over time, especially if they're not in a rush for immediate results.

Wet & Forget Moss, Mold, Mildew, & Algae Stain Remover is a liquid concentrate designed for outdoor surfaces, including concrete, wood, roofs, siding, and more. Its main appeal lies in the easy application: you mix it with water, spray on a dry surface, and then simply wait without scrubbing or rinsing. This method is convenient for users who want low-effort maintenance. The product works gradually, with green stains showing improvement in 1-2 weeks, while tougher black stains may take several months, which is important to know if you want quick results. It can keep surfaces cleaner for up to a year, making it a longer-term solution.

Wet & Forget is fragrance-free and safe to use on many materials, reducing concerns about harsh chemicals or strong smells. However, it requires dry weather and temperatures above freezing for application, and the effectiveness depends on natural rain and wind to wash away the dead mildew, which might not suit all climates or urgent cleaning needs. User ratings are positive, averaging 4.6 out of 5 stars, indicating general satisfaction with its performance.

This product is a suitable option for those looking for a no-scrub, multi-surface mildew cleaner with lasting effects, but it may not be ideal if fast or intensive stain removal is required.