Best Way To Apply Thompson Water Seal On Your Deck

Thompson Water Seal is a popular choice for homeowners who want to protect their decks from the elements. A Thompson Water Seal will prolong your deck’s life and keep it in the best shape for years to come.

But can you apply it yourself?

In this blog post, you’ll discover the best way to apply Thompson Water Seal on your deck so that it will last for years.

A decking outside in the rain

Benefits Of Thompson's Water Seal

Thompson’s Water Seal has been in the market for a very long time, and it’s proven to be an excellent product.

There are plenty of benefits to this sealant, and we believe it’s worth knowing everything about a product before investing in one.

Apply Thompson Water Seal To Make Redecorating Easy

The perfect way to update your old and favorite room is with Thompson’s water seal. With a wide variety of colors available, you can find the shade that best suits your style and budget. Make your deck match the interior of your home so everything about your home will flow, making the transition feel seamless.

Unlike other sealers that offer minimal protection, this semi-transparent stain will defend your new deck from UV rays and UV damage. Exposure to direct sunlight and mold will not harm your deck anymore, and this sealer’s natural color will make your deck nothing short of impressive.

Seals Out The Water

Thompson’s Water Seal is a one-step process that can be applied to damp wood, leaving it clean and dry. It seals out the water so your decking will last longer, without it risking rot or water damage.

Low Odor

Thompson’s water seal is the perfect product to work with if you have children or pets. The low odor makes it easier for people that are sensitive about smells.

However, you should still wear a mask for increased safety when you apply Thompson water seal.

Works Great Against Mildew

Molds and mildew can ruin your deck. Fortunately, this sealant is the perfect solution to stop this from happening. A coat of this high-quality sealant will protect against water damage and humidity.


This sealant dries immediately after installation. Thompson’s water seal does not dry when the coat is still vulnerable and gets wet. To avoid that from happening, when you’re done applying it, make sure there is no rain coming and try to avoid spilling liquids on it.


Unlike other sealants, Thompson’s water seal is resistant enough to last for 10 years. Its color and protective characteristics will remain top-notch, and your deck will keep its glory for years to come.

Apply Thompson Water Seal On Treated Wood

Thompson’s water seal allows you to apply a coat even to new pressure-treated wood. For best results, all you need to do is clean the surface first.
A brush to apply thompson water seal on a deck

How To Apply Thompson Water Seal

A coat of Thompson’s water seal is important for your deck. It stops the water from getting in and makes it last longer.

However, the right application process is just as important. Not everyone knows the mistakes you can make while applying this sealant. An incorrect application will cause bigger problems down the road, such as rot, mildew, or warping.

Read on to discover how proper application protects your deck and ensures water won’t cause any damage in years to come.

1. Before You Apply Thompson Water Seal

Before getting started on any project, it’s best to clean your workspace. An organized surface increases your productivity when applying the sealer for the first time.

Productivity is shaped by your surroundings; that’s why nobody likes to work in a messy environment. Let’s see how to prepare before you apply Thompson water seal…

Clean the Surface

Besides organizing the workspace, you should also clean your wood’s surface before applying Thompson’s water seal. This will prevent the paint pad from getting clogged with debris and dust. Take the time and clean the surface before starting the project, ensuring a smoother application.

Things you’ll need:

Steps to take:

Cleaning an Unfinished Wood To Apply Thompson Water Seal

Before you apply Thompson water seal, use a dry microfiber cloth or rag to clean the surface of an unfinished wood deck.

Keep in mind that using a wet microfiber cloth to clean the surface of an unfinished wood could make the wooden boards warp or get damaged.

To check if your wooden deck is finished or not, add a drop of water on its surface. If it absorbs the water drop and leaves a mark, your deck is unfinished.

Steps to take:

A deck being pressure washed before applying thompson water seal

2. Apply Thompson Water Seal On The Clean Surface

When you apply Thompson water seal, it’s up to you whether you want to use a sprayer or a paint pad. A garden sprayer makes the job easier, but if you don’t have access to one, a piece of cloth or even a small brush could work just fine.

Things you’ll need:

Steps to take:

If you’re not using a pump up garden sprayer, use your piece of cloth or brush directly in the sealant can, and then apply it to the deck surface.

The process may take longer than with a sprayer, but the results will be similar.

Using a Paint Pad

Depending on your project, you may want to use a paint pad, a piece of cloth, or a roller to apply your product.

Using a sprayer is definitely the fastest way to get the job done, but there are some alternatives if you don’t want to spend money on a sprayer.

Things you’ll need:

Steps to take:

Wait For The Water Seal To Dry

Give your Thompson’s water seal at least 24 hours to dry thoroughly. Depending on the weather, drying time may vary.

Keep in mind that if you want to apply latex paint over it—you should give the sealant at least 45 days to settle properly.

Cost Of Thompson Water Sealeant

You can find Thompson Water Seal at Walmart for around $20 a gallon, or order it on Amazon for $31 for 1.2 gallons.

Other Deck Sealing Alternatives

Maybe you can’t find Thompson Water Sealant in your local home improvement store, or maybe you just don’t like the brand. That’s fine. 

There are dozens of other alternatives to use on your deck. Here are just a few more:

Frequently Asked Questions

Yes. Only one coat of this sealant is enough to protect your deck from mold, mildew damage, and rain. Even more, one coat ensures great UV protection to keep your entire deck healthy. Consider applying this sealant on a finished deck, as this will provide extra protection and will make your deck last even longer.

A second coat is not necessary, but it can ensure maximum protection for the entire surface of your decking boards.

Yes. A pump-up sprayer is the fastest method of applying this sealant. However, you can use a paint pad, a brush, or a roller to apply it, and you will have similar results.
Yes. Thompson’s water seal protects your deck from both mildew and mold damage.

Although it is recommended to use a pump-up sprayer, you can also apply this sealant with a roller, a brush, or a paint pad. Keep in mind that you’ll need a rolling tray, a medium nap paint roller, and even an extension pole.

A plastic sprayer is relatively cheap, and you can find one for your personal preference at your home improvement store.

On average, Thompson’s water seal will last for about 5 years. Depending on the weather patterns in your area, this deck sealer might need your attention more often.

In a rainy state, you might need a fresh coat of water seal for ultimate protection every 2-3 years.


Thompson’s Water Seal is a great way to protect your deck and keep it looking new.

The preparation process is important to achieve the best results. Applying the sealer with a sprayer is the most efficient way to cover the surface, but be sure to take precautions when doing so.

While applying the sealant might be easy, the wrong surface preparation can make all your money go to waste. At the same time, applying the sealant is a time consuming chore, and you have better things to do.

Here at DeckBros, we have years of experience in applying sealants and stains on wood decks. If you want a quality sealant application for your deck in Omaha, NE, we can take care of everything for you. Get your free quote today!

Get in touch today and let’s upgrade your space!