Does your deck or fence built with pressure-treated wood look dull and weathered? You spent good money on that wood, and you want it to last. Protecting pressure-treated wood from sun and rain is super important. But when you step into the store, a wall of sealants greets you. Which one actually works? Choosing the wrong sealant can lead to peeling, cracking, and wasted time and money.
Many homeowners feel confused. Should you use an oil-based product or a water-based one? Do you need a stain or just a clear sealer? These questions stop people from protecting their investment. We understand the frustration of wanting a beautiful, long-lasting outdoor space without the guesswork.
This post cuts through the confusion. We will break down exactly what you need to know about sealants for pressure-treated wood. You will learn the key differences between products, how to pick the best one for your project, and simple steps to apply it correctly. Get ready to give your wood the long-term protection it deserves.
Top Sealant For Pressure Treated Wood Recommendations
- Ready to use clear sealant and waterproofer
- Perfect for new wood, pressure-treated wood, weathered wood and wood with a weathered clear or semi-transparent stain
- Durable sealant that provides waterproofing protection
- Repels water
- Provides SUNBLOCK UV protection
- New and improved
- The sealer of choice
- Protects against end grain checking
- Protect your wood investment
- Nearly 30 years of experience in making this product
- Ready to use clear wood sealant and waterproofer
- Perfect for new wood, pressure-treated wood, weathered wood and wood with a weathered clear or semi-transparent stain
- Durable water base sealant that provides waterproofing protection; Coverage up to 350 sq. ft. per gallon
- Repels water
- Provides SUNBLOCK UV protection
- Ready to use clear wood sealant and waterproofer
- Perfect for new wood, pressure-treated wood, weathered wood and wood with a weathered clear or semi-transparent stain
- Durable water base sealant that provides waterproofing protection; Coverage up to 350 sq. ft. per gallon
- Repels water
- Provides SUNBLOCK UV protection
- WATER-REPELLENT WOOD CARE: This penetrating wood treatment is formulated to help create a hydrophobic barrier that repels water and routine surface contaminants, supporting long-term wood appearance across outdoor conditions.
- NATURAL, NO-GLOSS FINISH: Provides a clear, natural look that maintains wood’s aesthetic while allowing it to weather and age naturally over time. Ideal for those who prefer a subtle, low-sheen finish.
- CLEAR, LOW-ODOR, VOC-CONSCIOUS FORMULA: Crafted with a water-based, low-odor blend mindful of VOC levels, making it suitable for various application environments without overwhelming fumes.
- EASY APPLICATION & BROAD COVERAGE: Covers up to approximately 200 sq. ft. per gallon and is designed for a smooth, straightforward application process—whether using a sprayer, brush, or roller.
- INDOOR & OUTDOOR WOOD USE: Versatile enough for decks, fences, siding, and wood furniture in both indoor and outdoor settings, offering consistent performance across multiple project types.
- MARINE SEALANT: Our liquid formula creates a UV-stable coating for protection against the elements, saltwater spray, and water damage. Marine is a great protector for outdoor furniture, thermally modified wood, and boat docks. Marine is safe for use over open water and is non-hazardous to aquatic life.
- DECK STAIN: It's water-based, ultra-low VOC, great for enhancing the extended life of your flooring, siding, and porch. The paint forms a water-resistant shield around wood fibers at the cellular level to help preserve the natural color.
- WATERPROOF WOOD SEALER: The wood used on boat docks, decks, and retaining walls near rivers, lakes, oceans, and ponds is subjected to constant moisture. We crafted a sealer, remove stain, and finish all in one, specifically for these installations.
- WOOD SEALANT: Our fast-drying protector penetrates wood below the surface, coating the wood fibers at the cellular level, which creates a long-lasting, flexible, breathable barrier. It provides a no-fuss, easy clean-up with soap and water.
- SEAL-ONCE: Our user-friendly wood sealers and stains are an effective way to protect your lumber or concrete against water damage. When you use Seal-Once, you have the satisfaction of knowing our products will not harm pets, plants, or people.
- It is easy to use
- It is highly durable
- Manufactured in United States
- Model number: 902
- PROFESSIONAL-GRADE PROTECTION FOR ALL WOOD TYPES: Our premium wood sealer penetrates deep into wood surfaces to help protect against the effects of moisture, sun exposure, and outdoor wear. Suitable for cedar, pine, hardwood, bamboo, and pressure-treated wood. A great choice for garden beds, planter boxes, fences, and other outdoor wood structures. Note: Not recommended for laminated or coated wood.
- PLANT-BASED FORMULA – FREE FROM HARSH FUMES: Made with naturally derived ingredients, this formula contains no synthetic solvents, waxes, or strong odors. Designed with your garden and family in mind, it’s a safe choice for spaces shared with plants and pets.
- LONG-LASTING PERFORMANCE WITH LESS MAINTENANCE: Unlike surface coatings that wear away quickly, our formula bonds with wood to help extend its appearance and durability over time. Helps minimize the impact of outdoor elements such as water and sun.
- HOME GARDEN & PET-FRIENDLY USE: Great for DIY garden projects, home planters, and wooden enclosures near pets. Perfect for raised beds, flower boxes, and other non-painted outdoor wooden items.
- EASY APPLICATION & LASTING RESULTS: Apply using a brush, roller, or sprayer—just two coats on a clean, dry surface are all it takes. Dries in approximately 2 hours between coats. Covers Up To 50–200 sq ft depending on the wood’s porosity. NOTE: Before applying, ensure the wood is clean, dry (moisture content < 15%), smooth, and free from dust, grease, and old coatings.
Choosing the Best Sealant for Pressure Treated Wood: A Buyer’s Guide
Pressure-treated wood resists rot and bugs. That’s great! But even treated wood needs protection from the sun and rain. A good sealant keeps your deck, fence, or outdoor furniture looking good for longer. This guide helps you pick the right one.
Key Features to Look For
When shopping for sealant, look closely at the label. Certain features make a sealant much better for treated wood.
- UV Protection: Sunlight breaks down wood fibers, causing graying. Good sealants contain UV blockers. These act like sunscreen for your wood.
- Water Repellency: The sealant must push water away. This stops moisture from soaking in, which prevents cracking, warping, and mildew growth.
- Mildew and Mold Resistance: Since treated wood sits outside, mold can still try to grow. Look for products that have added mildewcides.
- Penetration Level: Some sealants just sit on top (a film). Others soak deep into the wood grain. Deep penetration usually lasts longer and offers better protection.
Important Materials in Sealants
Sealants come in different chemical bases. Each one works differently with pressure-treated lumber.
Oil-Based vs. Water-Based
Oil-Based Sealants: These often penetrate deeper into the wood. They tend to offer excellent water protection and last a long time. However, they can take longer to dry, and cleanup requires mineral spirits or paint thinner.
Water-Based (Acrylic) Sealants: These are easier to use. They clean up easily with soap and water. Modern water-based formulas offer great UV protection. They are often more flexible, which helps them resist peeling as the wood naturally expands and contracts.
Hybrid Formulas: Some new products mix the best parts of both oil and water bases. These are worth considering if you want good penetration without difficult cleanup.
Factors That Improve or Reduce Quality
Not all sealants perform the same way, even if they look similar on the shelf.
What Makes Sealant Quality Better?
High-quality sealants use more solids. Solids are the parts of the product that actually stay on the wood after it dries. More solids mean a thicker, more durable protective layer. Also, look for sealants that contain natural oils or resins, as these improve flexibility and help the sealant bond well with the chemicals already in the treated wood.
What Reduces Sealant Quality?
Using the wrong type of sealant reduces quality fast. If you put a standard exterior stain on brand-new pressure-treated wood, it might not stick well. Treated wood often releases moisture for a while after purchase. Applying a sealant too soon can trap that moisture, causing the sealant to fail quickly. Always let the wood dry out completely before sealing.
User Experience and Use Cases
How you plan to use the wood changes which sealant you should buy.
Decks and Walkways (High Traffic)
For decks, durability is number one. You need a product that resists foot traffic and constant moisture exposure. Oil-based or heavy-duty acrylics that offer good abrasion resistance are best here. You will likely need to reapply every 2-3 years.
Fences and Siding (Lower Traffic)
For fences or the sides of sheds, appearance and UV protection matter more than heavy abrasion resistance. A good semi-transparent water-based sealant often works perfectly. These are easier to apply and maintain.
Application Tip: Always test the sealant on a small, hidden area first. This lets you check the color and make sure the wood absorbs the product correctly. Applying two thin coats usually gives better results than one very thick coat.
10 FAQs About Sealing Pressure Treated Wood
Q: When should I seal new pressure-treated wood?
A: You must let the wood dry out first. New treated wood is often very wet. Wait until the wood turns a grayish color and passes the “water bead test” (water soaks in instead of beading up). This can take several weeks or even months.
Q: Can I use a regular exterior stain on treated wood?
A: You can, but look for stains specifically labeled as safe for pressure-treated lumber. The chemicals in the treatment process can sometimes prevent standard stains from sticking properly.
Q: Does sealant stop the wood from rotting?
A: Pressure treatment stops the initial rot. The sealant adds another layer of defense by blocking surface water and UV rays, helping the original treatment last longer.
Q: How often do I need to reseal my deck?
A: Generally, you should inspect your deck every year. Reapply the sealant every 2 to 4 years, depending on the product used and how much sun and rain the deck gets.
Q: Will sealant change the color of my wood?
A: Yes. Sealants come in clear, semi-transparent (adds slight color), and solid color stains. Clear sealants protect the wood but let the natural graying show through more quickly.
Q: What is the “water bead test”?
A: Sprinkle some water on the wood surface. If the water beads up like marbles, the wood is still sealed or too wet to accept new sealant. If the water soaks in quickly, the wood is ready to be sealed.
Q: Is an oil-based or water-based sealant better for decks?
A: Both work well. Oil-based products often penetrate better, but water-based products dry faster and are easier to clean up, which many DIYers prefer.
Q: Do I need to clean the wood before sealing?
A: Absolutely. You must clean off dirt, mildew, and any old, failing sealant using a wood brightener or deck cleaner. Clean wood accepts the new sealant much better.
Q: Can I seal pressure-treated wood if it has been painted?
A: No. You cannot effectively seal paint. If the wood was previously painted or fully covered with a solid stain, you must strip or sand off the old coating before applying a new sealant.
Q: Does sealing help prevent cracking?
A: Yes. By controlling how fast the wood loses or gains moisture, the sealant helps reduce the stress that causes shrinking, splitting, and cracking.