10 Best Cedar Deck Sealers 2025 in the United States

The Ready Seal 512 5-Gallon Pail Natural Cedar Exterior Stain and Sealer is an oil-based product designed specifically for wood surfaces. It stands out for its easy application process, requiring no primer, back brushing, or special temperature conditions for proper application. This 'goof-proof' application is ideal for users who may not have extensive experience with sealing decks, as it prevents laps, runs, and streaks.

Additionally, it can be applied using a sprayer, roller, or brush, adding to its versatility. The product offers strong UV resistance, which helps in protecting the wood from sun damage, enhancing the longevity of the finish. Water resistance is another key feature, providing a robust barrier against moisture, which can be critical for maintaining the integrity of a cedar deck.

However, it's worth noting that the true color of the sealer only becomes apparent approximately 14 days after application, which may require some patience. The sealer also cannot be applied over painted or newly stained surfaces, as they inhibit penetration. This may limit its use for some projects. This sealer is especially suitable for those seeking an easy-to-apply, UV and water-resistant product for cedar decks, provided they can accommodate its specific application requirements.

Ready Seal 120 Redwood Exterior Stain and Sealer is designed specifically for wood surfaces like cedar decks. One of its biggest advantages is ease of use—it requires no primer, no back brushing, and doesn’t need thinning before spraying. This makes it very beginner-friendly and helps avoid common application problems like runs or streaks. The sealer is oil-based and flat finish, providing a natural redwood color that darkens initially and settles into its true shade after about two weeks. It offers good protection against UV rays, mildew, and mold, which are important for outdoor wood exposed to sun and moisture. Water resistance is also decent, helping to prevent water damage and warping over time. Coverage is reasonable at around 125 square feet per gallon, which suits small to medium projects.

It’s important not to apply this product over painted or freshly stained surfaces since it seals tightly and won’t penetrate well afterward. Some users might find that the flat finish is less glossy than other options, which could be a matter of personal preference. Also, while Ready Seal performs well, heavier foot traffic areas or extremely harsh weather might require more frequent reapplication compared to thicker sealers.

This sealer serves as a solid choice for homeowners seeking a straightforward, effective way to protect and beautify cedar decks without complicated preparation or application steps.

The SEAL-ONCE Marine Ready Mix is a water-based, polyurethane sealer designed specifically for wood exposed to high moisture, such as docks, decks, and piers. It offers solid UV protection by forming a UV-stable coating that helps prevent sun damage and fading, which is important for cedar decks exposed to sunlight. Its water resistance is strong thanks to a penetrating formula that waterproofs wood fibers below the surface, making it well suited to handle constant moisture and saltwater exposure. This also adds mildew and mold resistance, since the sealer blocks moisture that can cause fungal growth.

The product is easy to apply with a fast-drying, low-VOC formula that cleans up with soap and water, making it safer for pets, plants, and people around your deck area. Durability-wise, it creates a flexible, breathable barrier that lasts, reducing the need for frequent reapplications. This sealer carries a satin finish, which enhances the natural look of cedar but may not offer as glossy a look as some other options. While it is highly effective for wood exposed to marine conditions, it may be somewhat specialized for those seeking to seal a backyard cedar deck without extreme moisture concerns.

This product represents a strong choice for those wanting a reliable, environmentally friendly sealer that excels in protecting wood in wet environments and maintaining the appearance of cedar decks over time.