Do You Need a Pressure-Treated Wood Sealer for Cut Ends?

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Pressure treatment can improve the structural integrity of the wood. But it can still be vulnerable to harsh elements and may deteriorate sooner if you don’t protect it with the right sealer. 

So, our expert woodworkers prepared this comprehensive guide for using and choosing the pressure-treated wood sealer for cut ends to help you give maximum protection to your woodworking project. 

What to Know About Pressure-Treated Wood or Lumber

Pressure-treated wood is a type of lumber that is preserved by injecting a chemical into the wood, then sealing it with pressure. 

lumber pressure treated

This wood preservation process involves seal cut treatment, which uses big tanks to inject chemicals into the wood to make it resistant to moisture.

This chemical treatment also provides greater protection to the wood and extends its longevity. Generally, this procedure makes the wood more durable and suitable for construction use. 

The coating chemicals used include type C copper, which helps to preserve the structural integrity of the wood even when submerged in the water. 

Why it Needs to Be Sealed

It is crucial to treat wood used for your construction projects to prevent damage and decay, especially for your outdoor furniture and exterior structures. 

If you’re using pressure-treated wood, it is necessary to seal them for the following reasons.

applying wood sealer
  1. Sealing your pressure-treated wood prevents rot caused by moisture, and the wood lasts longer when used in exterior applications.
  2. Sealing stops rainwater from seeping in and prevents cracks and warping caused by swelling, which is common in untreated wood.
  3. The sealant protects the wood from fungal decay, insects, and micro-organisms infestation.
  4. Sealing your wood provides maximum protection and preserves the wood’s natural color and beauty. 

Do You Need to Seal the Cut Ends of Pressure-Treated Wood?

Yes, it is necessary to seal the cut ends of your pressure-treated wood to prevent moisture from seeping through and causing it to deteriorate prematurely. 

If the cut ends are exposed, they can easily absorb moisture, which can lead to rot and reduce the lifespan of your treated wood. 

pressure treated lumber

Using high-quality sealants, such as special end-cut solutions or waterproof sealants, can extend the longevity of your pressure-treated wood.

What Should I Use to Seal Cut Ends of Pressure-Treated Wood?

Before sealing the cut ends of your pressure-treated wood, it is important to prep them properly. This involves removing debris and dirt buildup on the wood. Also, you must ensure that injected preservatives in the wood are completely dry. 

When choosing sealing materials, you must pick the sealant that is compatible with your wood board’s appearance.  Below are the materials and tools you will need to seal the cut ends of your pressure-treated wood. 

Sealant for Cut Ends

We suggest you choose a sealant with copper naphthenate, which can preserve the ends of the treated wood. Most sealants available in the market have 1% copper, which is enough to protect the cut ends. 


Use a soft bristle brush to apply the sealant on the pressure-treated wood. Gently swipe a generous amount of sealant on the wood surface. 

paint brush

The number of coats depends on the quality of the sealant you’re using, so you must always refer to the product label and follow the application instructions. 

Abrasive Scrub

You must use an abrasive scrub to remove the dirt and debris on the wood surface and rub the cut ends before applying any chemical treatment. This step is crucial to ensure that the chemical will get through the wood.  

Step-by-Step Guide to the Sealing Process

Step #1: Time the Right End Cut Treatment

It is vital to choose the right time to treat the cut ends of the wood to make the process more efficient. We suggest you pick a warm and windless day to apply the sealant, especially for your outdoor furniture and structures.

Some chemicals used to treat the wood take a longer time to dry. You must check if your timber is ready for coating by pouring water on the surface. If beads are formed, your deck is dry enough to accept sealant coats. 

Step #2: Choose the Right Sealant

There are several factors you must consider when choosing the appropriate sealant for your treated wood. First, check the label of the product if it’s suitable for pressure-treated wood. 

staining pressure treated wood

Next, you must consider the location where it will be installed. For exterior use, choose a sealant that offers protection against harsh elements. But how long does pressure-treated wood last outside? Find out next!

Finally, choose a sealant according to your desired finish. Some sealants alter the wood’s characteristics, while others preserve the wood’s natural look.  

Step #3: Spread the Sealant Evenly

Use a paintbrush or paint pad to apply the sealant on the wood surface. Test first the sealant on a hidden portion of the wood to see the color on the surface and determine the right stroke. 

 Ensure to apply a thin coat to avoid spills and excess sealant. Work on a small section at a time to achieve an even coat. You may need to apply a second coating depending on the quality of your sealant and your desired result. 

Step #4: Wait for it to Dry

Allow the sealant to dry for 24 to 48 hours. Ensure that the sealant is fully dry before using the wood for a better finish. 

drying stain

Why Isn’t it Recommended to Cut Pressure-Treated Wood?

Treated wood contains a high amount of moisture and chemicals to preserve the wood. Cutting it will dry out the preservative content of the wood. 

As a result, the treated wood becomes vulnerable to degradation and harm caused by adverse elements.

Our Top Picks for a Pressure-Treated Lumber Cut End Sealer

1. Rust-Oleum 1904A Wolman (Woodlife) Copper Coat Green Wood Preservative

If you’re looking for a superb product that can save your exterior wood against termites, ants, and beetles, this sealer from Rust-Oleum is the best choice for you. 

It contains copper, making it an excellent finish for pressure-treated wood. It protects the wood against moisture, rain, UV rays [1], and other harmful elements. 

It’s ready to use and easy to apply using a paint roller or brush. We like how fast it dries, and it gives a smoother and glossier finish. But can you really use Rust-Oleum on wood? Read next!

What We Like

What We Don't Like

2. Thompson's WaterSeal TH.042851-16 Semi-Transparent Waterproofing Stain

If you’re on a budget but need a sealant that can protect your treated wood from water damage, this waterproofing stain is what you’re looking for. 

It’s suitable for your outdoor furniture, fences, and decks since it can completely protect the wood from harsh environmental conditions. 

You can also apply the Thompson’s WaterSeal with a sprayer, and it works as a sealant and stain in just one coat, so you can save a lot of money. It comes in different colors, giving a beautiful finish to pressure-treated wood.

What We Like

What We Don't Like

3. Ready Seal 512 5-Gallon Pail Natural Cedar Exterior Stain and Sealer

If you’re a beginner or a DIYer looking for a sealer that’s easier to apply, Ready Seal is just for you. 

You can easily achieve a smoother finish with this stain and sealer in one. It does not require priming, stripping, or sanding the wood, so you can save more time.  

Although when applied to pressure-treated wood, it may turn its color darker. But don’t worry because the wood’s natural color comes back in two weeks. After that, it guarantees to prolong the beauty and integrity of any treated wood. 

What We Like

What We Don't Like


How is pressure-treated wood cut?

The pressure-treated wood must be cut with extra precautions since it contains harmful chemicals. It’s necessary to wear your protective gear, such as gloves, goggles, and a mask. Ensure that the sealant has dry completely before cutting the wood, so the chemicals and moisture will not dry out.  


Now that you know the right pressure-treated wood sealer for cut ends, you can ensure that your treated wood will be protected from mold, mildew, termites, and harsh environmental conditions. 

This will help you preserve the structural integrity of your treated wood, making it more durable and long-lasting.  

Robert Johnson is a woodworker who takes joy in sharing his passion for creating to the rest of the world. His brainchild, Sawinery, allowed him to do so as well as connect with other craftsmen. He has since built an enviable workshop for himself and an equally impressive online accomplishment: an extensive resource site serving old timers and novices alike.
Robert Johnson
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