Does Pressure Treated Wood Need to Be Sealed?

Did you know that pressure-treated wood can last up to 40 years without significant decay? That’s right! This longevity is due to a process known as pressure treatment, a method of preserving wood to extend its life and resist insects and decay. This type of wood is commonly used in outdoor settings, such as decks, fences, and landscaping projects, where durability and resistance to the elements are key.

Pressure-treated wood, also known as treated or preserved wood, undergoes a specialized process where it’s infused with chemicals to resist rot and insects. This process makes it a popular choice for outdoor wood projects. But here’s a question that often pops up: does this wood, with its built-in protection, need additional sealing? Let’s dive into that.

Does Pressure Treated Wood Need to Be Sealed, and Why?

The short answer is that pressure-treated wood benefits from being sealed, but why? Isn’t it already ‘treated’ to withstand the elements? While pressure treatment provides protection, sealing adds an extra defense against the elements, particularly moisture.

Despite the chemical treatment, pressure-treated wood can still absorb water. Over time, this can lead to warping, cracking, or even rot. Sealing the wood helps to prevent this water absorption, thereby extending the life of the wood even further.

Consider this: imagine you’re building a deck. You’ve chosen pressure-treated wood for its durability and resistance to decay. But, if left unsealed, the wood can absorb rainwater, leading to potential damage over time. Sealing the wood provides a barrier against this moisture, ensuring your deck remains strong and beautiful for years.

In essence, while pressure-treated wood is more resistant to decay and insects, sealing it protects particularly against moisture damage. So, if you want your outdoor wood projects to stand the test of time, grabbing that can of sealant is a wise move.

Caring for your wood doesn’t stop at the treatment process. It’s an ongoing commitment. But with the right care, including regular sealing, your pressure-treated wood can remain robust and visually appealing for many years. Now, isn’t that a comforting thought?

What Happens If You Don’t Seal Pressure Treated Wood?

So, you’ve decided to skip the sealing process for your pressure-treated wood. But what exactly are the consequences of this decision? Let’s just say it’s like skipping sunscreen on a scorching summer day. You might not notice the effects immediately, but the damage becomes apparent over time.

Unsealed pressure-treated wood is more susceptible to the damaging effects of moisture. When the wood absorbs water, it can lead to various issues, including warping, cracking, and even rot. This can significantly affect the lifespan and appearance of your wood.

Imagine your beautifully crafted outdoor deck slowly warping out of shape, the boards twisting and turning in ways they shouldn’t. Or picture the vibrant, rich color of your wooden fence fading and becoming discolored due to exposure to rain and sun. These are the realities of unsealed treated wood.

Moreover, the absorbed water can freeze in colder climates, causing the wood to crack. Over time, these cracks can become larger, leading to structural instability. In extreme cases, the wood can even start to rot from the inside, despite the pressure treatment.

In essence, not sealing your pressure-treated wood can lead to premature aging and damage, reducing its lifespan and aesthetic appeal. It’s like buying a high-end sports car and then neglecting its maintenance. Sure, it might run smoothly for a while, but eventually, the lack of care will catch up, leading to problems.

Best Treatment for Pressure Treated Wood

Now that we’ve established the importance of sealing pressure-treated wood, let’s discuss the best treatments available. There’s a wide range of products on the market, each with pros and cons. The key is choosing a sealant that offers high-quality protection and suits your needs and environment.

One highly recommended product is Thompson’s WaterSeal Advanced Natural Wood Protector. This sealant provides powerful protection against water damage and UV rays, helping to maintain the color and integrity of your wood. It’s easy to apply and dries quickly, making it a popular choice for many DIY enthusiasts.

Another top contender is the Ready Seal Natural Cedar Exterior Wood Stain and Sealer. This oil-based product penetrates deeply into the wood, offering robust protection against the elements. Plus, it enhances the natural beauty of the wood, adding a rich, warm tone.

On the other hand, if you’re looking for a more eco-friendly option, consider the Tall Earth Eco-Safe Wood Treatment. This non-toxic sealant offers long-lasting protection against decay and pests without using harsh chemicals.

Can You Use Thompson Water Seal on Pressure Treated Wood?

Absolutely! Thompson’s WaterSeal is a fantastic choice for pressure-treated wood. This sealant is designed to protect against water damage and UV rays, making it an excellent option for outdoor wood projects.

Thompson’s WaterSeal penetrates deep into the wood, providing a robust barrier against moisture. It also helps to preserve the wood’s color, preventing it from fading under the harsh sun. Plus, it’s easy to apply and dries quickly, making your DIY project a breeze.

But how does it compare to other brands? Well, Thompson’s WaterSeal is often praised for its durability and ease of use. However, other brands like Ready Seal and Tall Earth offer high-quality products. Ready Seal is known for its deep penetration and natural finish, while Tall Earth stands out for its eco-friendly formula. Ultimately, the choice depends on your specific needs and preferences.

So, if you’re considering Thompson’s WaterSeal for your pressure-treated wood, go for it! It’s a reliable choice that offers solid protection, helping to extend the life and maintain the beauty of your wood.

How Long Will Pressure Treated Wood Last If Not Sealed?

Pressure-treated wood is designed to resist decay and insects, making it more durable than untreated wood. However, if left unsealed, its lifespan can be significantly reduced.

Unsealed pressure-treated wood can last anywhere from 10 to 20 years, depending on the conditions it’s exposed to. Factors such as climate, exposure to sunlight, and how well the wood is maintained can all affect its longevity.

For instance, in a humid climate where the wood is constantly exposed to moisture, unsealed pressure-treated wood may show signs of decay in as little as 10 years. On the other hand, in a dry climate with minimal exposure to the elements, the wood might last up to 20 years.

However, it’s important to note that these are just estimates. The actual lifespan of unsealed pressure-treated wood can vary widely based on many factors. That’s why it’s always recommended to seal your pressure-treated wood. Sealing extends the wood’s lifespan and helps maintain its appearance, ensuring your outdoor projects stay beautiful for years.

How Soon Can You Seal Pressure-Treated Wood?

When it comes to sealing pressure-treated wood, timing is everything. Seal it too soon, and the sealant may not adhere properly. Wait too long, and the wood may start to deteriorate. So, when is the perfect time to seal your pressure-treated wood?

Generally, waiting at least 30 days after the wood has been installed is recommended before applying a sealant. This gives the wood enough time to dry from the pressure treatment process. However, this timeline can vary depending on the type of wood and the climate in which you live.

It may take longer to dry out completely in humid climates, where the wood is exposed to much moisture. In this case, you might need to wait up to 60 days before sealing. On the other hand, in dry climates, the wood may be ready for sealing in as little as 2-3 weeks.

How to Seal Pressure Treated Wood Fence

Sealing a pressure-treated wood fence is a straightforward process that can significantly extend the life of your fence. Here’s a step-by-step guide on how to do it:

  1. Clean the Fence: Start by cleaning the fence thoroughly. Remove any dirt, debris, or mildew. A power washer can be a great tool, but a regular garden hose with a spray nozzle can do the job.
  2. Let it Dry: After cleaning, let the fence dry completely. Depending on the weather, this can take 24 to 48 hours.
  3. Apply the Sealant: Once the fence is dry, apply the sealant. Use a paintbrush, roller, or sprayer, depending on the size of the fence and your preference. Make sure to cover all surfaces, including the tops of the posts, which are often overlooked.
  4. Let it Dry: Allow the sealant to dry according to the manufacturer’s instructions. This usually takes 24 to 48 hours.
  5. Apply a Second Coat (Optional): Depending on the sealant you’re using and the condition of your fence, you might want to apply a second coat for extra protection.
  6. Maintain Regularly: Once your fence is sealed, check it regularly for any signs of wear or damage. Properly, your sealed pressure-treated wood fence can last many years.

Is It Better to Stain or Seal Pressure Treated Wood?

The choice between staining and sealing pressure-treated wood often comes down to the desired appearance and level of maintenance you’re willing to commit to. Both options have pros and cons; the best choice depends on your specific needs and preferences.

Staining pressure-treated wood can enhance its natural beauty while protecting the elements. Stains penetrate the wood, offering UV protection and helping to prevent moisture damage. They also come in various colors, allowing you to customize the look of your wood. However, stains typically require more frequent reapplication than sealants, usually every 2-3 years.

On the other hand, sealing provides a clear finish that showcases the wood’s natural grain. Sealants form a protective barrier on the wood’s surface, preventing water absorption and offering UV protection. They’re often easier to apply than stains and usually last longer, typically needing reapplication every 3-5 years.

So, is it better to stain or seal pressure-treated wood? Staining could be the way to go if you want to enhance the wood’s color and don’t mind more maintenance. Sealing might be your best bet if you prefer a natural look with less frequent upkeep.

Is It Okay if Pressure Treated Wood Gets Wet?

Pressure-treated wood is designed to withstand the elements, including rain and snow. So, yes, it’s okay if pressure-treated wood gets wet. However, that doesn’t mean it’s impervious to water damage.

While the pressure-treating process makes the wood more resistant to rot and insects, it doesn’t completely waterproof. Over time, repeated exposure to moisture can lead to issues like warping, cracking, and even decay.

That’s where sealing comes in. Applying a high-quality sealant to your pressure-treated wood creates a protective barrier that prevents water absorption, helping to safeguard against these potential issues.

So, while it’s okay if your pressure-treated wood gets wet, protecting it from water damage is still important. Regular sealing and proper maintenance can help ensure your wood stays strong and beautiful, no matter what Mother Nature throws.

Is Pressure Treated Wood Waterproof?

Pressure-treated wood is often praised for its durability and resistance to decay and insects. But does this mean it’s waterproof? Well, not exactly.

While pressure-treated wood is more moisture-resistant than untreated wood, it’s not completely waterproof. The pressure-treating process involves infusing the wood with chemicals that help resist rot and insects but doesn’t make it impervious to water.

When exposed to moisture, pressure-treated wood can still absorb water, leading to warping, swelling, or even cracking over time. This is particularly true in environments with high humidity or frequent rainfall.

That’s why, despite its inherent resistance to decay, pressure-treated wood can benefit from additional waterproofing measures, such as applying a high-quality sealant. This can help further protect the wood from water damage, enhancing its durability and longevity.

So, while pressure-treated wood is certainly more water-resistant than untreated wood, it’s not completely waterproof. But with proper care and maintenance, including regular sealing, it can effectively withstand the elements and serve you well for many years.

Sealing Pressure Treated Wood After Cutting

When you cut pressure-treated wood, you expose a section that hasn’t been infused with the protective chemicals used in the pressure-treating process. This exposed area can be more susceptible to moisture, decay, and insect damage. That’s why sealing the cut ends of pressure-treated wood is important.

The cut ends can be sealed using a product specifically designed for this purpose, such as a cut-end wood preservative or sealant. These products are typically easy to apply and dry quickly, providing a protective barrier that helps to prevent decay and extend the life of the wood.

Here’s a simple step-by-step guide on how to do it:

  1. Clean the Cut Ends: Clean the cut ends of the wood to remove sawdust or debris.
  2. Apply the Sealant: Using a paintbrush, apply a generous cut-end sealant to the exposed wood. Be sure to cover the entire cut surface.
  3. Let it Dry: Allow the sealant to dry according to the manufacturer’s instructions. This usually takes a few hours.
  4. Reapply if Necessary: In some cases, you might need to apply a second coat of sealant for added protection.

Water Repellent Sealer for Pressure Treated Wood

Water-repellent sealers are a fantastic choice for pressure-treated wood. They provide a protective barrier that helps prevent water absorption, which can lead to warping, cracking, and decay. But not all water-repellent sealers are created equal. Let’s dive into some top-notch options and their benefits.

Thompson’s WaterSeal Advanced Natural Wood Protector is popular with many homeowners. This sealer provides strong protection against water damage and UV rays, helping to maintain the color and integrity of your wood. It’s easy to apply and dries quickly, making it a practical choice for DIY enthusiasts.

Ready Seal Natural Cedar Exterior Wood Stain and Sealer is another excellent option. This oil-based product penetrates deeply into the wood, offering robust protection against the elements. It also enhances the natural beauty of the wood, adding a rich, warm tone.

Olympic Stain Waterguard Waterproofing Sealant is a clear sealant that provides superior waterproofing protection while allowing the wood’s natural color to shine through. It’s resistant to mildew and UV damage, making it a great choice for outdoor wood projects.

Eco Advance Wood Siloxane Waterproofer is an eco-friendly option that provides long-lasting water repellency without harsh chemicals. It’s safe for people, pets, and plants, making it an excellent choice for environmentally conscious homeowners.

What Happens If You Stain Treated Wood Too Soon?

Staining pressure-treated wood too soon can lead to a host of problems. The most common issue is that the stain may not adhere properly to the wood. This is because pressure-treated wood is often still wet from the treatment process. Applying stain to the wood while still damp may not penetrate it effectively, leading to uneven color and poor protection.

Additionally, staining wet wood can trap moisture beneath the stain, which can lead to peeling or blistering as the wood dries. It can also increase the risk of mold and mildew growth, damaging the wood and shortening its lifespan.

So, how can you tell when your pressure-treated wood is ready for staining? A simple test is to sprinkle a few drops of water on the wood. If the water beads up, the wood is still too wet. If it soaks in, the wood is dry and ready to be stained.

Remember, patience is key when it comes to staining pressure-treated wood. Giving the wood ample time to dry before staining can help ensure a beautiful, long-lasting finish.


Sealing pressure-treated wood is an essential step in ensuring its longevity and durability. Whether it’s a deck, a fence, or outdoor furniture, pressure-treated wood needs proper care and maintenance to withstand the elements and stay beautiful for years.

From understanding the importance of sealing and the consequences of neglecting this crucial step to exploring the best treatments available and learning how to apply them properly, we’ve covered much ground in this article. We’ve also delved into the specifics of using products like Thompson’s WaterSeal and discussed the effects of staining the wood too soon.