10 Best Waterproof Deck Sealers 2025 in the United States

The Ready Seal 512 5-Gallon Pail Natural Cedar Exterior Stain and Sealer for Wood offers a number of appealing features for anyone looking to protect their outdoor wood surfaces. This oil-based product requires no primer and can be applied using a sprayer, roller, or brush, making it quite versatile and user-friendly. One of its standout characteristics is the 'Goof Proof' application – it does not require back brushing, and it blends itself to avoid any laps, runs, or streaks, even when applied in varying temperatures. This makes it particularly easy to apply, even for those with little to no experience in staining and sealing wood. Additionally, it does not need diluting or thinning prior to spray application, further simplifying the process.

From a performance perspective, the Ready Seal 512 provides good water resistance and is UV resistant, helping preserve the wood's natural appearance and protect it from weathering and sun damage. The fact that it reaches its true color in about 14 days can be a minor inconvenience for those seeking immediate results. On the durability front, it is reliable and long-lasting, making it suitable for exterior use on various wood surfaces like decks and fences. However, the product should not be applied over painted or recently stained surfaces, as sealed surfaces inhibit penetration. Another consideration is its environmental impact; as an oil-based product, it may not be the most eco-friendly option available. Some states also include a PaintCare recycling fee, which is an additional cost.

With its ease of application and effective protection, this stain and sealer is a strong contender for anyone needing to maintain their wooden outdoor structures.

The SEAL-ONCE Marine Ready Mix is a water-based, penetrating wood sealer designed specifically for high-moisture outdoor areas such as docks, decks, and piers. Its liquid formula provides strong water resistance by creating a barrier that protects wood at the cellular level, helping prevent water damage and preserve the wood's natural color. It also offers UV protection through a stable coating that guards against sun damage and saltwater spray, making it suitable for marine environments.

One of its standout features is being eco-friendly, with an ultra-low VOC content that is safe for aquatic life and pets, which is great for environmentally conscious users. The sealer dries quickly and is easy to clean up with soap and water, making application straightforward even for those without much experience. Additionally, it forms a flexible, breathable layer that supports long-lasting durability without cracking or peeling.

While this product is excellent for wood and outdoor use near water, it is specifically made for wood only and will not work on other materials. Being a penetrating sealer, it may require reapplication over time to maintain protection, especially in very harsh conditions. This product is suitable for anyone needing a reliable, non-toxic wood sealer for decks or docks exposed to water and sunlight, combining strong performance with ease of use and environmental care.

The Seal-Once Nano+Poly Penetrating Wood Sealer is a water-based polyurethane finish designed to deeply protect wood by soaking in rather than just coating the surface. This means it creates a water-resistant barrier that helps prevent wood damage and deterioration from exposure to the elements. Its water-based formula is low in odor and VOCs, making it safer for your family, pets, and plants, and easier to clean up with just soap and water. It also offers UV stability, so it helps protect wood from sun damage while allowing the wood to age naturally without turning overly dark or yellow. The sealer dries relatively fast and is flexible, which is good for outdoor wood that expands and contracts with weather changes.

It comes in a large 5-gallon size, ideal for bigger projects like decks, fences, or outdoor furniture. On the downside, its water resistance is rated as "water resistant" rather than fully waterproof, so in extremely wet conditions, it might need reapplication more often than some heavier-duty oil-based sealers. Also, while it penetrates well, it has a gloss finish option that may highlight imperfections in older wood if you prefer a more matte look. Application is straightforward, but due to its size and weight (over 40 pounds), handling and storage require some effort.

For those looking for an environmentally friendlier, easy-to-use sealer that protects wood outdoors from water and UV damage while maintaining natural wood appearance, this product fits well. However, if you need maximum waterproofing for very wet climates or prefer a more matte look, you might explore other options.