Thompson’s WaterSeal Waterproofer Plus Clear Wood Protector Review 2.5/5 (273)

This post was updated on April 6, 2026

Hi, I’m Scott Paul

As a leading exterior restoration contractor and business owner with over 30 years of experience in exterior wood decking, I’ve worked extensively with a variety of products to protect and enhance wood surfaces.

My review of Thompson’s Water Seal is rooted in decades of hands-on testing and my professional experience as a wood restoration contractor. My goal is to provide you with honest insights and guide you toward the best deck stain options to ensure your project’s success.

For more about my background and expertise, feel free to read more about me here.

6.125 Overall Rating Thompsons WaterSeal

Thompson’s WaterSeal Wood Finish is a widely available water-repellent product designed to protect exterior wood from moisture while adding light color. It is commonly sold as an easy-to-use solution for homeowners looking to seal and protect decks, fences, and other outdoor wood surfaces.

From my experience restoring decks since 1993, Thompson’s WaterSeal products are more of a basic sealer than a true deck stain. While they can provide short-term water protection, they typically lack the UV resistance and long-term durability needed for consistent performance on a deck.

Overall, Thompson’s WaterSeal can be used for temporary protection, but it is not one of the better choices for long-lasting deck staining results.

🔹 Thompson’s WaterSeal Wood Finish – Quick Verdict

• Best For: Short-term water protection and quick projects
• Not Ideal For: Long-term durability and UV protection
• Type: Water-based wood sealer with light pigment
• My Overall Rating: 6.125/10

My Take:
Thompson’s WaterSeal is easy to use and widely available, but from my experience, it does not hold up well long term and requires frequent reapplication.

If you have any experience with this product, we’d love it if you shared your Thompson’s WaterSeal reviews and photos in the comment area below.

Key Takeaways from Our Thompson’s Water Seal Review

• No UV protection – The stain grayed within months, failing its primary job of preserving wood.
• Good water resistance, but short-lived – Initially repels water well, but loses effectiveness by the 2-year mark.
• Mold and mildew issues – Encourages black mold growth over time, making maintenance a hassle.
• Easy to apply – Applies smoothly with a sprayer or pad, with no overlap marks.
• Not recommended – Fails in key areas like UV protection and long-term durability—better alternatives exist.

Thompson’s WaterSeal Clear Waterproofer Ratings & Reviews (Out of 10)

8-Step Review of Thompson’s WaterSeal Clear Wood Protector

1. Appearance After Initial Stain Application: 8

This Thompson’s WaterSeal clear waterproofer did not alter the appearance of the wood. After it was fully dry, we tested its ability to repel water, and water did bead on top of the finish and did not absorb into the wood.

2. Preventing UV Graying at 2-Year Mark: 1

As far as we can tell, Thompson’s WaterSeal product does not prevent UV graying. This is a huge disappointment, as preventing UV graying is the number one reason to stain your exterior wood and decking.

3. Wear/Tear and Peeling: 8

The Thompson’s WaterSeal clear waterproofer penetrates deep into the wood. There was no peeling or wearing. We would have given it a 10 if the product still repelled water, but at the 2-year mark, it did not.

4. Cost per Square Foot: 9

Thompson’s WaterSeal Waterproofer Plus Clear Wood Protector is a very inexpensive product with exceptional coverage. Unfortunately, the saying “you get what you pay for” applies here, as Thompson’s WaterSeal product offers no UV protection.

5. Preventing Mold/Mildew/Algae: 2

After 2 years, the entire deck was covered in black mold. It seems that the oils used in Thompson’s WaterSeal Waterproofer Plus Clear Wood Protector feed and promote the growth of mold spores.

6. Ease of Application: 8

Since this is a clear product, it applies exceptionally easily without the need to backwipe. Just apply it with a pump sprayer or stain pad. This finish does not show overlap marks.

7. Color Shifting (Darkening) After 2 Years: 7

This product darkens in color because there is a good amount of mold growing in the finish.

8. Difficulty of Reapplication: 6

A heavy cleaning would be needed to remove the graying and mold from the surface.

Thompson’s Water Seal Clear Waterproofer Overall Score 6.1

Thompson’s WaterSeal Waterproofer Plus Clear Wood Protector: A Clear Disappointment

The Thompson’s WaterSeal Waterproofer Plus Clear Wood Protector falls short of expectations. While it claims to protect exterior wood, it offers zero UV protection, which is critical for preventing graying and preserving the natural beauty of your deck or other wood surfaces.

My Verdict

Any finish that lacks the ability to prevent UV graying simply cannot be recommended for decks or exterior wood. If you’re looking for a product that truly protects and enhances your wood surfaces, we suggest exploring better alternatives.

Thompson’s WaterSeal Clear Waterproofer Photos and Results

Product Information

• Cost: $39.99 per gallon
• Stain Type: Clear water repellent
• Available Colors: Clear
• Application Temperature: 45-95 degrees F
• Coats Required: 1
• Coverage per Gallon: 200-300 square feet
• Application Tools: Sprayer, pad, brush, roller
• Dry Time: 48 hours
• Cleanup: Mineral spirits
• VOC Compliance: 250 compliant in all states
• More Info: Product Data
• Manufacturer: Thompson’s

About Our Test Deck

• Deck Wood Type: Teak
• Deck Square Footage: 400 square feet
• UV Exposure: Full sun
• How Many Years Tested: 2 years
• Stain Color Used: Clear

All products tested, and the results are from our experience. We offer no guarantee of similar results. Consider that results may differ due to different wood types, exposure to UV radiation, and natural weathering.

Thompson’s WaterSeal FAQs: Oil vs. Water-Based and More

Is Thompson’s WaterSeal Any Good?

Our overall experience with Thompson’s WaterSeal Waterproofer Plus Clear Wood Protector was disappointing, and we would not recommend it. Its inability to prevent UV graying is too harmful to your deck’s wood.

What’s Better Than Thompson’s WaterSeal Waterproofer?

Restore-A-Deck Semi-transparent Stain and Armstrong-Clark Transparent Stain are excellent alternatives to Thompson’s WaterSeal Waterproofer Plus Clear Wood Protector.

Restore-A-Deck Semi-Transparent Wood Stain 1 Gallon

$51.99

5out of 5

Select options This product has multiple variants. The options may be chosen on the product page

Restore-A-Deck Semi-Transparent Wood Stain 5 Gallons

$239.99 – $257.99Price range: $239.99 through $257.99

5out of 5

Select options This product has multiple variants. The options may be chosen on the product page

Armstrong Clark Stain 1 Gallon

$72.95 – $83.95Price range: $72.95 through $83.95

5out of 5

Select options This product has multiple variants. The options may be chosen on the product page

Armstrong Clark Stain 5 Gallon

$284.95 – $344.95Price range: $284.95 through $344.95

Select options This product has multiple variants. The options may be chosen on the product page

Armstrong Clark Stain 5 Gallon and Cleaner/Brightener Kit

$336.00 – $395.00Price range: $336.00 through $395.00

Select options This product has multiple variants. The options may be chosen on the product page

Armstrong Clark Stain 5 Gallon and Stripper/Brightener Kit

$351.00 – $405.00Price range: $351.00 through $405.00

Select options This product has multiple variants. The options may be chosen on the product page

How Long Does Thompson’s WaterSeal Last?

Thompson’s WaterSeal Waterproofer Plus Clear Wood Protector claims to last up to 4 years when applied correctly. In our experience, it held up well but no longer repelled water after 6-12 months.

Is Thompson’s WaterSeal Waterproof?

Thompson’s WaterSeal Waterproofer Plus Clear Wood Protector is made to waterproof exterior wood.

Can You Use Too Much Thompson’s WaterSeal?

Yes: Applying too much Thompson’s WaterSeal clear waterproofer will significantly increase the time it takes to dry, and it may not dry properly.

Does Thompson WaterSeal Protect Wood?

Thompson’s WaterSeal Waterproofer Plus Clear Wood Protector is intended to protect wood, as the name would indicate, but our testing produced dismal results. It does a very poor job of preventing black mold and UV graying, which are very harmful to the wood.

Is Thompson’s WaterSeal Water- or Oil-Based?

Thompson’s WaterSeal Waterproofer Plus Clear Wood Protector is an oil-based product.

How Do You Use Thompson’s WaterSeal Waterproofer Plus Clear Wood Protector?

This product is easy to apply with either a stain pad or a pump sprayer.

Does Thompson’s WaterSeal Contain Silicone?

No, this Thompson’s WaterSeal product does not contain silicone.

Does Thompson’s WaterSeal Come in Different Colors?

This particular product is clear, but they also make Thompson’s WaterSeal Waterproofer products that include Thompson’s stain in different colors.

How Many Coats of Thompson’s WaterSeal Do I Need?

In most cases, you will only require one coat.

Can Thompson’s WaterSeal Be Used on Stained Wood?

No, Thompson’s WaterSeal Waterproofer Plus Clear Wood Protector cannot be applied over stained wood, regardless of whether the stain was oil- or water-based.

Does Thompson’s WaterSeal Darken Wood?

Our review of Thompson’s WaterSeal Waterproofer Plus Clear Wood Protector found that it did darken wood over time due to the large amount of black mold that grew in the finish.

How Long Does Thompson’s WaterSeal Take to Dry?

The Thompson’s WaterSeal dry time is approximately 4-24 hours before it is considered safe to walk on.

At What Temperature Can You Apply Thompson’s WaterSeal?

The application temperature for Thompson’s WaterSeal products is between 45°F and 95°F.

🔹 Thompson’s WaterSeal Wood Finish – Pros and Cons

Pros

• Easy to apply with minimal effort
• Widely available and affordable
• Provides short-term water repellency
• Good for quick projects or temporary protection
• Can be used on multiple exterior wood surfaces

Cons

• Very limited UV protection
• Short lifespan compared to higher-quality stains
• Requires frequent reapplication
• Does not penetrate deeply into the wood
• Not suitable for long-term deck protection

🔹 Best Wood Types for Thompson’s WaterSeal

• Decks needing temporary protection
• Fences or low-traffic wood surfaces

Not Ideal For:

• Full sun decks – will fade quickly
• Decks needing long-term durability
• Hardwoods (IPE, Cumaru, etc.) – not effective

👉 See: Deck Stain for New Wood
https://www.deckstainhelp.com/staining-a-new-deck/

🔹 Application Tips

• Apply to properly cleaned and prepped wood
• Apply thin, even coats
• Do not over-apply
• Best used in low to moderate exposure conditions

👉 How to Prep a Deck
https://www.deckstainhelp.com/best-deck-prep-clean-strip-or-sand-the-deck/

👉 How to Stain a Deck
https://www.deckstainhelp.com/how-to-stain-a-deck/

🔹 Maintenance & Recoat Tips

Maintenance is frequent with products like Thompson’s WaterSeal.

• Reapply every 6–12 months depending on exposure
• Clean and brighten before reapplication
• Monitor for water absorption and fading
• Expect shorter lifespan compared to true stains

From my experience, these types of sealers require constant upkeep to maintain protection.

👉 Deck Cleaning and Brightening
https://www.deckstainhelp.com/cleaning-wood-deck/

🔹 Who Should Use Thompson’s WaterSeal?

You should consider Thompson’s WaterSeal if:

• You want a quick and inexpensive solution
• You need short-term water protection
• Your project is low priority or temporary
• You are not concerned with long-term durability

You may want to consider other options if:

• You want long-lasting protection
• Your deck is exposed to full sun
• You prefer a stain with better UV resistance and longevity

👉 Best Deck Stains
https://www.deckstainhelp.com/the-5-best-deck-stain-reviews-and-ratings/

🔹 Thompson’s WaterSeal Wood Finish – Final Thoughts

Thompson’s WaterSeal Wood Finish is a basic water-repellent product that provides short-term protection but lacks the durability and UV resistance needed for long-term deck performance.

From my hands-on experience, products like this require frequent reapplication and do not hold up well compared to higher-quality stains that penetrate and protect the wood more effectively.

If you are looking for a quick, temporary solution, Thompson’s WaterSeal can work. For most deck owners, however, investing in a better-quality stain will provide far better long-term results and easier maintenance.

Scott Paul ~ Restoring Wood & Decks Since 1993 Owner

As an article and comment contributor to the site, Scott has been around the pressure washing industry since attending college. In 1993 he started his first company called Oakland Pressure Wash specializing in exterior pressure washing and deck staining. That company evolved into OPW L.L.C. shortly thereafter concentrating more on exterior wood and deck restoration. Scott and his Deck Cleaning Michigan company have restored over 10,000 decks in the Metro Detroit area since the early years. He has become an authority in the deck restoration industry and has contributed to numerous wood restoration forums and informative sites. All the products he suggests through this site are sold through online sites and in retail stores, allowing the consumer to choose their own means of purchase. Scott’s eCommerce sites do sell many top brands he endorses and if you appreciate any of the help he has offered then feel free to purchase from one of them.

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