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The Best Outdoor Wood Sealers of 2024 for Fences, Decks, and Furniture

Keep your deck, fence, and wooden furniture looking great by protecting them with an outdoor wood sealer.

Best Overall

A gallon can of Seal-Once Nano+Poly Penetrating Wood Sealer on a white background.

Seal-Once Nano+Poly Premium Wood Sealer

Best Bang for the Buck

A jug of Rain Guard Water Sealer on a white background.

Rain Guard Natural Finish Wood Sealer

Best Oil-Based

A can of Ready Seal Wood Stain and Sealer on a white background.

Ready Seal Wood Stain and Sealer

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Wood decks, fences, and outdoor furniture live a hard life exposed to rain, snow, and sun, which is why it’s important to protect them with a quality outdoor wood sealer. These sealers create an exterior coating that repels water while also blocking harmful ultraviolet (UV) radiation that can dry out wood, causing it to splinter and crack. We examined over 40 wood sealers that offer a range of color options, transparency, and finishes to choose the top 10 products. We put those 10 products to the test by applying each to various wood species, then subjecting them to water and foot traffic. 

The outdoor wood sealers we reviewed encompass a range of types, from oil- and water-based formulas to solid and clear coatings. Our top pick is Seal-Once Nano+Poly Premium Wood sealer, which is low in volatile organic compounds (VOCs), creates a durable waterproof shell over wood, and has strong abrasion resistance. Below, we’ll review what factors you’ll want to consider when shopping for the best wood sealers and offer our top recommendations.

  1. BEST OVERALL: Seal-Once Nano+Poly Penetrating Wood Sealer
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  2. BEST BANG FOR THE BUCK: Rain Guard Natural Finish Wood Sealer
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  3. BEST OIL-BASED: Ready Seal Exterior Stain and Sealer
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  4. BEST WATER-BASED: Olympic WaterGuard Clear Wood Sealer
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  5. BEST SOLID: SaverSystems #1 Deck Advanced Solid Color Wood Stain
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  6. BEST SEMITRANSPARENT: SaverSystems #1 Deck Premium Wood Stain
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  7. BEST CLEAR: Thompson’s WaterSeal Clear Multisurface Waterproofer
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  8. BEST ECO-FRIENDLY: Eco Advance Exterior Wood Water Repellent
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  9. BEST UV PROTECTION: Seal-Once Marine Premium Wood Sealer
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  10. BEST AGAINST MILDEW: Owatrol Textrol Exterior Wood Sealer
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A lineup of the best outdoor wood sealers on wood boards during testing.
Photo: Tony Carrick for Bob Vila

How We Tested the Best Outdoor Wood Sealers

Our testing of the top 10 exterior wood sealers was based on four criteria: application, appearance, durability, and value. We first assessed how easy each wood sealer was to apply along with drying time. After applying each stain to three different types of wood species, we considered its appearance and how well it matched the color on the can or, for clear products, how well they preserved the original look for the wood. 

After giving each product the recommended amount of time to cure, we simulated both weather and foot traffic. We evaluated scuff resistance by walking on the boards repeatedly and dragging patio furniture across them, taking note of any scratches. We also exposed each to water by spraying them or, in some cases, briefly leaving them out in rainy weather. Finally, we considered value by comparing the coverage and price of each product. 

Testing Stats
Products tested10
Hours spent testing5 hours
Tests performed3
Price range$18 to $64

Our Top Picks

We considered several features while researching the best outdoor wood sealers, including type, transparency, water resistance, UV resistance, ease of application, environmental impact, and overall value. Whether you’re looking for a way to seal a deck or protect a new fence, you’re sure to find an option that’s right for you. 

Best Overall

Seal-Once Nano+Poly Penetrating Wood Sealer

 A gallon can of Seal-Once Nano+Poly Penetrating Wood Sealer on a white background.
Photo: Amazon

Our Ratings: Application 3.5/5; Appearance 5/5; Durability 5/5; Value 3.5/5

Product Specs 

  • Type: Water-based
  • Transparency: Clear
  • Resists: Water, mold, decay, UV, abrasion

What We Like

  • Low-VOC formula produces fewer smelly fumes than other wood sealers
  • Provides great weather protection with high water and UV resistance 
  • Ideal for high-traffic areas thanks to strong abrasion resistance

What We Don’t Like

  • Thin consistency makes it a challenge to apply with a brush or roller
  • Costs several times more than other wood sealers 

One of the most important factors to keep in mind while searching for an outdoor wood sealer is that wood is vulnerable to more than just water damage. UV radiation can crack and splinter wood, while heavy foot traffic can cause abrasive damage, leaving it susceptible to rain and moisture. This Seal-Once outdoor wood sealer is designed to protect decks, fences, and outdoor furniture from water, mold, decay, UV radiation, and abrasion.

The sealant is completely clear, allowing the natural beauty of the wood to show through, and relies on a UV-stable formula to protect from the sun. This water-based product has low VOCs and is nontoxic, making it a good option for homes with kids or pets. 

While our short period of testing didn’t allow us to evaluate its abilities to protect from UV rays, we were able to get a sense of the sealer’s weather-resistant qualities. As wood sealers go, Seal-Once is on the watery side, which means application is most effective by using a sprayer to apply thin coats over the material. 

After applying two coats and giving it the recommended 24 hours to cure, we subjected Seal-Once to our spray test. Water beaded up well on the surface of all three test pieces, demonstrating that Seal-Once protects against both water and sun damage. Seal-Once also remained scuff-free after subjecting it to foot traffic and furniture legs. 

Seal-Once is among the most expensive sealants out there, but it’s worth the splurge if you want to protect your wood deck, fence, or outdoor furniture.

Get the Seal-Once Nano+Poly outdoor wood sealer at Amazon, The Home Depot, or Seal-Once.

Best Bang for the Buck

Rain Guard Water Sealer

 A jug of Rain Guard Water Sealer on a white background.
Photo: Amazon

Our Ratings: Application 3.7/5; Appearance 4/5; Durability 4/5; Value 4.5/5

Product Specs 

  • Type: Water-based
  • Transparency: Clear
  • Resists: Water, mold, decay, UV

What We Like

  • Contains UV stabilizers that protect wood from harmful UV rays
  • Concentrated formula makes up to 2 gallons of sealer
  • Can be applied with a sprayer, brush, or roller

What We Don’t Like

  • Concentrated formula must be mixed before application

Designed for tackling larger projects on a budget, Rain Guard water sealer comes in a concentrated form that needs to be mixed with water at a ratio of 7:1 in order to make up to 2 gallons of wood sealer. This product has a clear finish that allows the natural color of the wood and the natural wood grain to show through, making it a great option for users who prefer the look of the deck or fence over a solid or semitransparent color tint.

We had mixed results with Rain Guard during testing. The product was one of the more watery sealers we tested, which made applying it with anything other than a sprayer difficult as it runs easily. We did like how this sealer is completely transparent. Some supposedly “clear” sealers still slightly change the color of the wood. Rain Guard did not. 

Given the name of the product, we had high expectations for its rain resistance, and Rain Guard for the most part delivered. Rain beaded up on its surface during our spray test, though water didn’t dance off the surface as much as it did with other pricier wood sealers we tested. 

While its thin consistency makes it a challenge to apply, Rain Guard is a good budget-priced option for larger projects that demand a sprayer application. 

Get the Rain Guard outdoor wood sealer at Amazon, Lowe’s, or Rain Guard.

Best Oil-Based

Ready Seal Exterior Stain and Sealer

 A can of Ready Seal Wood Stain and Sealer on a white background.
Photo: Amazon

Our Ratings: Application 3.3/5; Appearance 5/5; Durability 5/5; Value 4/5 

Product Specs 

  • Type: Oil-based
  • Transparency: Semitransparent
  • Resists: Water, mold, decay, UV

What We Like

  • Comes in a range of colors to suit different preferences
  • High UV resistance provides ample protection from the sun’s harmful rays
  • Offers plenty of protection from water thanks to oil-based formula

What We Don’t Like

  • Takes much longer to dry and cure than water-based sealers

Many outdoor wood sealers are made with a water-based formula that is designed to dry quickly so that the user doesn’t need to worry about rain. But in fact, the longer time it takes for an oil-based sealer to dry, the better it is for achieving a more even finish. This Ready Seal wood sealer is an oil-based option that needs about 48 to 72 hours to fully cure, but the finished product makes it worth the wait, as long as the sealer is applied according to the manufacturer’s directions.

We tested a semitransparent combination stain and sealer that produced rich, even colors, accentuating the existing wood grain on our test pieces. After drying, it created a durable layer of protection. It resisted our best efforts to scuff it, and water beaded off it nicely during our spray tests. 

This sealer can be applied in any temperature as long as the wood is completely dry, and it comes in 10 color options, so users can get the look that they want instead of settling for what’s available. ReadySeal is pricier than other water sealers, but we feel it’s worth the additional cost for the level of protection it offers. 

Get the Ready Seal outdoor wood sealer at The Home Depot.

Best Water-Based

Olympic WaterGuard Clear Wood Sealer

 A can of Olympic WaterGuard Clear Wood Sealer on a white background.
Photo: The Home Depot

Our Ratings: Application 4/5; Appearance 4/5; Durability 3.5/5; Value 4/5

Product Specs 

  • Type: Water-based
  • Transparency: Clear, transparent, semitransparent
  • Resists: Water, mold, decay, UV

What We Like

  • Very affordable compared to other water- and oil-based wood sealers
  • Offers comprehensive protection with scuff, mildew, and UV resistance
  • Works on wood fences, siding, decks, and outdoor furniture 

What We Don’t Like

  • Watery consistency makes it difficult to apply with anything other than a sprayer
  • Doesn’t provide the same level of water resistance as other sealers

In addition to being affordable, the Olympic WaterGuard clear sealant provides waterproofing protection, has built-in Scuff-Guard technology, and is mildew- and UV-resistant. It’s also compatible with a variety of outdoor wood surfaces, including siding, fences, decks, and outdoor furniture. 

Since it’s water-based, Olympic’s sealer doesn’t produce the same fumes as acrylic wood sealers, and it’s also very easy to clean up. We tested the clear version of the sealer, though it also comes in a variety of colors in transparent and semitransparent finishes. 

Out of the can, Olympic is noticeably watery, which made it difficult to apply with a brush without drips and splatters. This is clearly a sealer that’s best applied in thin layers using a sprayer. We did like the fact that it only calls for a single coat.

We were a little disappointed with its weather resistance. While water didn’t soak into the wood we treated with Olympic, it didn’t bead up as it did with some of the other pricier wood sealers we tested. Olympic says the sealer provides protection for up to 4 years for fencing and 3 years for decks, but that claim seems ambitious. 

That said, if you’re looking for an affordable deck sealer or fence sealer and have a sprayer for application, then Olympic’s water sealant for wood is a worthy choice. 

Get the Olympic outdoor wood sealer at The Home Depot.

Best Solid

SaverSystems #1 Deck Advanced Solid Color Wood Stain

 A jug of SaverSystems #1 Deck Advanced Solid Color Wood Stain on a white background.
Photo: Amazon

Our Ratings: Application 4.7/5; Appearance 5/5; Durability 4/5; Value 4/5

Product Specs 

  • Type: Water-based
  • Transparency: Solid
  • Resists: Water, mold, decay, UV, fading, peeling

What We Like

  • Covers wood grain and imperfections in just 2 coats
  • Solid sealer provides exceptional protection from UV rays
  • Contains a low-odor, low-VOC solution that’s safer for the environment 
  • Quick dry time allows one to apply it over a short period of time

What We Don’t Like

  • Produces a matte finish that may not appeal to everyone 

Of all the solid outdoor wood sealers we tested, SaverSystems Advanced stood out for its ability to mask wood grain. It took just two coats to create an opaque, even coat over our test pieces of wood, which was impressive given that our test batch was white, a color that rarely masks well. Brush marks are a bit more noticeable with SaverSystems than with other solid deck stains and sealers. It also leaves more of a matte finish than other wood sealers, which may not appeal to some. 

This outdoor wood sealer goes on with a sprayer, paint brush, or roller and dries in just a couple of hours. You can choose from six color options, including white, light walnut, classic taupe, dark cocoa, dark walnut, and gray to get the finish that matches the outdoor aesthetic of your home. 

The SaverSystems products we’ve tested in the past have excellent scuff resistance, and this product was no exception. It did a great job of warding off our best attempts to scuff with shoe soles and furniture legs. SaverSystems also resisted water well when exposed to rain. If you’re looking to hide wood grain and imperfections in a deck or table with a solid stain while protecting it from the elements, SaverSystems Advanced is a great choice. 

Get the SaverSystems Advanced outdoor wood sealer at Amazon.

Best Semitransparent

SaverSystems #1 Deck Premium Semi-Transparent Stain

 A jug of SaverSystems #1 Deck Premium Semi-Transparent Stain on a white background.
Photo: Amazon

Our Ratings: Application 4.3/5; Appearance 5/5; Durability 3.5/5; Value 4/5

Product Specs 

  • Type: Water-based
  • Transparency: Semitransparent
  • Resists: Water, mold, decay, UV, fading

What We Like

  • Offers good UV protection from the sun and resists scuffs well 
  • Produces a beautiful finish that accentuates natural wood grain 
  • Dries quickly, with very little wait time between the first and second coat

What We Don’t Like

  • Doesn’t resist water as well as other wood sealers we tested

Intended to protect exterior objects like decks, fences, benches, chairs, and other wooden furniture from water, mildew, mold, and rot, this SaverSystems Premium wood sealer is available in five color options and two standard sizes. You can choose between a gallon of semitransparent sealer or, for handling larger jobs, a 2.5-gallon container. 

We loved how easily SaverSystems Premium went on. We were able to achieve an even coat with little effort. This sealer coats and protects the wood without covering up the natural wood grain. We also appreciated its low-VOC water-based formula, which gives off only a mild odor and makes cleanup easy. 

While SaverSystems Premium performed well during the scuff test, it didn’t resist water as well during our spray test, raising potential durability concerns. We only tested SaverSystems over a short period, but this could be an indication that it will require reapplication more often than other wood sealers. We also didn’t like the fact that SaverSystems Premium is only available in five color options, which could be a deal-breaker if you’re trying to coordinate the stain with your house color. 

We did like SaverSystems Premium’s low price tag, particularly for a product that covers up to 150 square feet with two coats. This semitransparent stain and sealer is a great option if you want an easy-to-apply deck stain that won’t break the bank. 

Get the SaverSystems Premium outdoor wood sealer at Amazon.

Best Clear

Thompson’s WaterSeal Clear Multisurface Waterproofer

 A can of Thompson’s WaterSeal Clear Multisurface Waterproofer on a white background.
Photo: Amazon

Our Ratings: Application 5/5; Appearance 4/5; Durability 4.5/5; Value 5/5

Product Specs 

  • Type: Water-based
  • Transparency: Clear
  • Resists: Water, UV rays

What We Like

  • Produces an excellent barrier that causes water to bead up on the surface
  • Fast-drying and single-coat formula make application fast 
  • Costs just a fraction of other outdoor wood sealers 

What We Don’t Like

  • Some customers report that certain colors don’t match the swatch on the can

If you’re after maximum protection for your deck or fence from the effects of water, then look no further than Thompson’s WaterSeal. The clear finish of this stain preserves the natural look of the wood while protecting it from water and harmful UV light. Thompson’s wood sealer also stands out from others in that it’s compatible with more than just wood surfaces. You can even use it as a brick and concrete sealer

Out of the can, there was a noticeable difference between Thompson’s WaterSeal and other wood sealers we tested. It has a thicker consistency, which made it far easier to apply with a brush or roller than the watery clear water sealers we tested that required two coats at quick time intervals. We didn’t have problems with splatters or drips, and achieving a consistent coat was easy. And since it only requires a single coat, applying Thompson’s is a quicker process than applying most water sealers.

Not surprisingly, Thompson’s excelled during our spray test. Water beaded up on the surface of all three of our test pieces. It also resisted our scuff tests well. Given Thomson’s excellent performance and low price tag, it’s a great choice if you’re after an all-purpose sealer for your deck, fence, driveway, brick siding, or patio. 

Get Thompson’s wood sealer at Amazon, Lowe’s, Ace Hardware, or Walmart.

Best Eco-Friendly

Eco Advance Exterior Wood Water Repellent

 A jug of Eco Advance Exterior Wood Water Repellent on a white background.
Photo: Amazon

Our Ratings: Application 4/5; Appearance 4/5; Durability 3.5/5; Value 4/5

Product Specs 

  • Type: Water-based
  • Transparency: Clear
  • Resists: Water, mold, decay, oil, salts, pool chemicals

What We Like

  • Nontoxic formula is safe for use around people, pets, and wildlife 
  • Easy to apply with a standard garden pump sprayer
  • Protects against oil, salt, and pool chemicals in addition to water and sun damage

What We Don’t Like

  • Shorter protection period than sealers that use harsher ingredients 

This water-based nontoxic nonflammable sealer is designed to protect exterior wood structures, furniture, and other wood objects from water, mold, mildew, and rot. It can also prevent damage from oil, salts, and pool chemicals while remaining an eco-friendly option. Its low-VOC formula is safe for use around people, pets, and your landscaping, though we still suggest covering any surrounding plantings. 

Along with its environmentally friendly formula, Eco Advance is also notable for its application process, which involves using a sprayer. The company doesn’t advise using a brush or roller, which makes sense given the solution’s thin consistency. The sprayer made applying Eco Advance fairly easy. We were able to get a thin, even layer over the wood and didn’t experience any clogging. 

Once dry, Eco Advance showed good weather-resistant qualities. During our spray test, Eco Advance did a fair job of repelling moisture. Water didn’t soak into the wood, but it also didn’t bead up nearly as well as it did on the oil-based products we tested. As a nontoxic spray on sealant for wood, Eco Advance may not offer the same level of protection as harsher wood sealers. Still, it’s certainly a quality eco-friendly option if you don’t mind needing to reapply it every year or two.

Get the Eco Advance outdoor wood sealer at Amazon, The Home Depot, or Walmart.

Best UV Protection

Seal-Once Marine Premium Wood Sealer

 A can of Seal-Once Marine Premium Wood Sealer on a white background.
Photo: Amazon

Our Ratings: Application 4/5; Appearance 4/5; Durability 5/5; Value 4/5

Product Specs 

  • Type: Water-based
  • Transparency: Clear
  • Resists: Water, mold, decay, salt water, UV, fading

What We Like

  • Built-in UV stabilizers provide exceptional protection from the sun 
  • Specially formulated to provide saltwater protection, making it ideal for the coast
  • Low-odor, low-VOC formula that’s safe for the environment and marine life 

What We Don’t Like

  • Costs several times more than other water-based outdoor wood sealers

Ocean air carries salt and high moisture levels that can seep into exterior structures, furniture, and other wooden objects, like siding. The water swells and warps the wood, attracting mold and mildew, while the salt dries out the wood fibers, causing it to crack and splinter. But you can protect these areas with the Seal-Once Marine Premium wood sealer, which is designed to waterproof docks, decks, and other wooden structures from water, mold, decay, rot, and salt water. The sealer is also designed with UV stabilizers to protect the wood from harmful UV radiation and prevent fading.

Seal-Once is an ultralow-VOC sealer and won’t harm pets, plants, or people. But it is a thinner solution, and was therefore a little tricker to apply with a brush. We recommend going with a sprayer. And since it requires adding the second coat while it’s still wet (within about 30 minutes), you’ll want to work quickly. 

That said, we found it to be worth the extra effort. Water immediately beaded up and rolled off the wood surface during a downpour, demonstrating that it’s more water-resistant than any sealer we tested. That said, this type of performance and protection doesn’t come cheap: Seal-Once costs three or four times the price of other sealers. Still, if you live in a humid coastal environment and want maximum protection, Seal-Once Marine is worth the extra cost.

Get the Seal-Once Marine outdoor wood sealer at Amazon, The Home Depot, or Seal-Once.

Best Against Mildew

Owatrol Textrol Exterior Wood Sealer

 A can of Owatrol Textrol Exterior Wood Sealer on a white background.
Photo: Amazon

Our Ratings: Application 4/5; Appearance 5/5; Durability 5/5; Value 3.5/5

Product Specs 

  • Type: Oil-based
  • Transparency: Clear
  • Resists: Water, mold, decay, UV rays

What We Like

  • Penetrates deep into the wood fibers to protect from water and UV rays
  • Thicker formula goes on smoothly, making application easier
  • Produces a finish that beautifies and revitalizes the wood

What We Don’t Like

  • Costs more than many other outdoor wood sealers 
  • Oil-based formula produces strong fumes and makes cleanup more difficult

Owatrol differentiates itself from other wood sealers with its revitalizing formula. It’s designed to penetrate deep into wood fibers, providing long-lasting protection that you won’t find with other wood sealers. Along with creating a barrier against UV rays and moisture, Owatrol also infuses wood with oils that help to preserve and revitalize it. 

Owatrol is more expensive than other wood sealers out there. Given its price tag, we had high expectations during testing, and Owatrol didn’t disappoint. It has a thicker consistency than other wood sealers we tested. It goes on smoothly and soaks deep into the wood grain. Owatrol does require two coats that you’ll want to apply within 30 minutes of each other, which can make application a little tricky if you’re covering a large area. It also needs to dry for 24 to 48 hours prior to rain exposure, so checking the weather carefully before getting started is key. 

After giving it 2 full days to dry, we subjected it to a downpour. Water beaded up and danced off the surface of all three test wood types. While we weren’t able to test Owatrol’s long-term durability, the amount of product that soaked into the wood during application suggests that Owatrol truly does penetrate deep beyond the surface, creating a thick barrier against the elements. So while Owatrol comes with a premium price, it’s also in a different class than other wood sealers when it comes to protection.

Get the Owatrol outdoor wood sealer at Amazon

Jump to Our Top Picks

The Best Outdoor Wood Sealers Options
Photo:Tony Carrick for Bob Vila

What to Consider When Choosing an Outdoor Wood Sealer

The best outdoor wood sealers all excel in certain areas, but the right one for your purposes will depend on specific factors. Therefore, it’s worth considering some more general characteristics of wood sealants before choosing one.

Types of Outdoor Wood Sealers

In general, wood sealers are differentiated by the formula and transparency. The main types include oil-based, water-based, solid/opaque, semitransparent, and clear.

Oil-Based vs. Water-Based

Outdoor wood sealers can be split into oil-based and water-based products, each with its own drawbacks and benefits. Many sealers are also made using polycrylic or polyurethane, two popular materials for wood finishing. Polycrylic is water-based, but polyurethane can have an oil or a water base.

  • Oil-based sealers are better for pine, cedar, oak, ash, and other types of wood that have a high absorption rate. This is because oil-based sealers are not as easy for the wood to absorb as water-based products. However, an oil-based wood sealer typically has better UV resistance and tends to have a more even finish.
  • Water-based sealers are ideal for wood with a low absorption rate, like alder, birch, and maple. They can also be used on oak and ash if a fast-drying alternative to oil-based sealers is needed. Water-based products are more environmentally friendly, though the fast drying time can result in an uneven or splotchy appearance.

Solid or Opaque

The transparency of a seal for outdoor wood contributes to its ability to provide UV protection to the wood. Like deck paint, solid or opaque outdoor wood sealer has very little transparency so that it completely covers the natural grain of the wood. This gives the wood a more uniform appearance in the color of the user’s choice. 

Solid wood sealer is the best transparency option for UV protection because the thick layer of colored/tinted sealer helps to repel UV rays. That helps it prevent not only discoloration but also sun damage to decks and other wood surfaces.

Semitransparent

The next option for sealant transparency is semitransparent products. These sealers protect the wood from rain, moisture, rot, and mildew as well as provide mild UV protection with a semitransparent tint or color. 

The semitransparent appearance allows the natural wood grain to show through. However, the color or tint in this type of outdoor wood sealant tends to fade faster than the color in solid or opaque sealers, so it may need to be reapplied about once every 2 to 3 years to maintain the appearance.

Clear

Paint and exterior wood stains are commonly available in a wide range of colors, but most outdoor wood sealers have a clear finish because they are specifically intended to protect the wood from water, mold, and mildew. 

UV protection is typically an added feature in clear sealers that results in a superior product, which allows such products to stand out from the competition. Clear sealers protect the wood without covering up the natural grain or natural color, though they are not as effective at repelling UV radiation as solid or semitransparent sealers. 

Water and Mildew Resistance

The purpose of an outdoor wood sealer is to protect the wood from rain, sleet, snow, humidity, and any other type of moisture that can cause wood rot, mold, or mildew. By providing a waterproof layer with mold and mildew resistance, the wood sealer prevents moisture from seeping into the fibers of the wood, avoiding swelling, shifting, warping, and tearing.

Mold and mildew pull moisture in from the air and collect rainwater to grow and thrive. This spreading growth can increase wood rot and also permanently discolor the wood, so it’s important to get rid of mold and mildew before it can start to spread. Applied correctly, a waterproof sealer for wood can prevent mold and mildew from growing at all. 

UV Protection

Similar to water and mildew resistance, UV protection is intended to extend the life of the wood by preventing ongoing damage. Outdoor wood sealers are typically made for repelling water, but solid, semitransparent, and some clear sealers do have UV-resistant properties. Opaque or solid oil-based outdoor wood sealers with stabilizers offer the highest level of UV protection of any outdoor sealer. 

Generally, oil-based sealers have a higher resistance to UV radiation than water-based sealers, while opaque/solid colors and tints shield the wood better than semitransparent or clear sealers. Semitransparent sealers still provide more UV protection than clear sealers, but if cracked and splintered wood from UV radiation is a recurring problem, it’s a good idea to invest in a solid oil-based wood sealer.

Application

To maximize your outdoor wood protection when using a sealer, it’s important to follow the steps for correct application. Most products can be applied with a paint brush or roller, and there are even some options that can be loaded into a paint sprayer. Oil-based sealers take longer to dry than water-based sealers, so make sure there is enough time for the sealer to cure before it rains. 

Water-based sealers dry quickly, but if applying the sealer when it’s too hot outside, the sealer may dry in splotchy or uneven patches. For best results, start applying in the morning when it’s still relatively cool. You may also want to prepare the wood by first cleaning it with a pressure washer, which can help remove mold, mildew, and any other dirt that may interfere with the sealant. 

It’s also important to remember that sealers repel all liquids, which means they must be applied carefully, particularly when it comes to adding a second or third coat. If the first coat is already dry or “set,” it will prevent the second coat from bonding to the wood. Therefore, if applying a second coat, make sure to do so before the initial layer has dried.

The number of coats and drying time needed for an outdoor wood sealer depend on the individual product. Even sealers made by the same manufacturer can have slight differences in coverage and drying time, though it should be noted that oil-based outdoor wood sealers typically need fewer coats than water-based sealers. 

Environmental Concerns

A key factor to keep in mind when selecting an outdoor wood sealer for the deck, fence, or exterior furniture is whether the formula contains VOCs or any other ingredients that could be harmful to the environment. Oil-based sealers tend to have a higher percentage of VOCs, though many water-based sealers still have a low amount of VOCs in their formulas.

The Best Wood Sealer
Photo: Tony Carrick for Bob Vila

Check the product information and the details from the manufacturer to find out the level of VOCs contained in the sealant before deciding on a product. Choose a low-VOC or VOC-free alternative to protect the environment from harmful runoff while keeping wooden structures and furniture safe.

FAQs

After you’ve settled on a wood sealer for your deck or fence, you may still be looking for some trips and tricks on how to use it. Read on to find answers to some of the most commonly asked questions about waterproofing and sealing wood for outdoors. 

Q. Should you seal all sides of wood?

You should seal all sides of a board or a piece of furniture, especially if all sides will be visible. Wooden objects that are installed or used outdoors should be completely sealed to help protect the item from rain, snow, and moisture.

Q. Do you sand wood after sealing?

No, you do not need to sand wood after sealing. We carefully followed the application instructions for all the wood sealers we tested and none called for sanding after applying the sealer.

Q. How long does exterior wood sealer last?

On average, exterior wood sealer is made to last for about 4 to 5 years, though it may begin to show signs of wear before this point, especially if the sealant was not properly applied. Always make sure to read and follow the manufacturer’s directions to get the best results.

Q. Will outdoor wood sealer withstand harsh weather conditions?

The main purpose of an outdoor sealant for wood is to create a waterproof layer that bonds to the exterior of the wood. Some sealants will also provide UV protection, though this is primarily reliant on the transparency of the product. With this in mind, a waterproof sealant can protect fences, decks, or wood furniture from rain, sleet, and snow, though they offer less defense against hail or strong winds, which can physically damage the wood. 

Q. Can you paint sealed wood?

When it comes to painting wood for outdoors, it isn’t recommended to paint over sealed wood because sealants are specifically designed to keep out moisture. This means that paint or stain will not adhere to the wood, resulting in bubbling, flaking, and chipping. However, you can protect painted surfaces with a good paint sealer for wood.

Meet the Tester

Tony Carrick is a freelance writer specializing in home improvement, landscaping, technology, home security, and design. His articles have been featured on such sites as Angi, Popular Science, Futurism, 360 Reviews by U.S. News & World Report, Domino, and more. Carrick has conducted rigorous product testing on everything from power tools to home security systems to backyard grills. With each review, his goal is to help readers determine whether a product meets their needs and if it is or isn’t worth its price tag. 

Additional research provided by Timothy Dale.

 
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Tony Carrick

Contributing Writer

Tony Carrick is a freelance writer who has contributed to BobVila.com since 2020. He writes how-to articles and product reviews in the areas of lawn and garden, home maintenance, home improvement, auto maintenance, housewares, and technology.

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