10 Best Outdoor Wood Sealers – Reviews and Buyer Guide

Last updated on February 1st, 2022

Wood has been used in construction for ages. Its warmth, calmness, and versatility make it a favorite for construction both inside and outside the home. Wood is excellent for constructing outdoor spaces because of its ability to blend with nature. However, it is prone to damage from insects and weather elements, rotting, and aging. Fortunately, wood sealers were invented to counter rotting in wood. The best outdoor wood sealers will preserve the integrity and aesthetic of your wooden patio, deck, gazebo, or outdoor furniture for years.  

Below is a list of the 10 best outdoor wood sealers to help you choose the wood sealer that will give you the maximum value on your project. The wood sealers have been rated and reviewed by other users on their projects.

10 Top-rated Outdoor Wood Sealers

  1. Thompsons Waterseal Wood Protector

Thompsons WaterSeal is famous for its easy application. It has a thick consistency that makes it easy to apply. Just one coat is enough to protect your wooden surfaces for at least two years.  Thompson’s WaterSeal can be applied to both damp and dry wood. It dries in less than an hour. When water comes into contact with the wooden surface post application, it rolls into balls and later evaporates naturally.

Thompsons WaterSeal Wood Protector is not only waterproof, but also has active ingredients that protect the wood from mold, fungi, mildew, and UV rays.

The sealer not only protects wooden surfaces; it also enhances the aesthetic aspect. Thompsons wood sealer does not change the color of wood but adds a bit of sheen to your wooden structure. It is also available five different color stains allowing you to choose the stain that best compliments your project.

Thompsons WaterSeal Wood protector is also low maintenance. Its water-based formula allows you to clean the surface with just soap and water. Ever wondered what 100 years of experience look like? You should try out Thompsons WaterSeal Wood Protector.


  • Dries in less than an hour
  • Protects from UV damage
  • Protects from mold and fungi
  • Does not alter the wood color
  • Suited for both damp and dry wood
  • Available in five stain colors
  • Odorless.


  • Pricy
  • Some users complain of yellowing
  • Too slick

2. Thompson’s WaterSeal 21802 Wood Protector

Thompsons WaterSeal 21802 is not only a sealer, it also doubles as a stain. The two-in-one factor coupled with its fair price makes it one of the most sought after products in the market.

It has a nice thick consistency that makes it pretty easy to apply with just a brush or a roller. One coat will do the trick and will dry in slightly over an hour. It can be applied to either damp wood or pressure-treated wood.

Thompsons Waterseal 21802 features in our list of best outdoor wood sealers because it’s great for wooden outdoor exteriors like benches, decks, patios, and gazebos because it is waterproof, UV resistant, and mildew resistant.

The sealer/stain not only preserves the wood quality; it also preserves the original charm. There is no color alteration to the wood post-application. Its formula also has advanced polymers that prevent fading of wood.


  • Pocket-friendly price
  • UV resistant
  • Mildew resistant
  • Thick consistency easy to apply
  • Doubles as a stain
  • Does not alter the wood color
  • Applicable to both damp and dry wood


  • Too thick to apply using a sprayer
  • Some users complain of oily scum post-application.

3. Ready Seal Natural Cedar Exterior Stain and Sealer.

Ready Seal stain and sealer is a money saver because it does not require the use of a primer on your structure before application. The stain/sealer is oil-based and semi-transparent.

The oil components in its formula help with waterproofing by penetrating the wood to preserve it. Ready Seal Stain and Sealer also protects the wood exterior from mold, mildew as well as UV damage.

Its semi-transparent nature preserves the charm and aesthetic integrity of each type of wood. You are still able to see the grain and texture of the wood post-application. The sealer/stain is available in nine different colors which include:

  • Light oak
  • Mahogany
  • Golden pine
  • Burnt hickory
  • Mission brown
  • Natural cedar
  • Pecan
  • Redwood

With all these options at hand, you will certainly find the perfect stain for your wood exteriors.

Ready Seal is one of the easiest to apply in the market. Whether or not you are an expert with a brush, you are guaranteed a clean finish free of runs, streaks, and back brush. Its consistency also allows you to a sprayer which is so much less labor-intensive. Another user-friendly feature is that Ready Seal is not too sensitive to temperature during application.


  • Does not require a primer before application
  • Semi-transparent finish that shows wood grain and texture
  • No visible runs, streaks, and back brush post application
  • Water-resistant
  • Protects from mold and mildew
  • Can be applied under varying temperature conditions.


  • Low coverage per gallon hence pricy.

4. Defy Crystal Clear Composite Deck Sealer

The best outdoor wood sealers should be formulated to make your wood exteriors defy both rain and shine, and that’s what defy crystal clear composite deck sealer does. The wood sealer features zinc nano-particle technology in its formula to protect wooden surfaces from UV rays.

Strong UV rays cause wood to lose color and turn to dull gray. The zinc particles in Defy deck sealer reflect UV rays off the wooden exterior. The deck sealer also protects wooden exteriors from fungi, mold, and mildew.

Defy Crystal Clear composite deck sealer is also semi-transparent hence the wood grain and texture still shine through post-application. High-quality resins in the sealer also prevent the wood from either fading or darkening hence preserving its aesthetic integrity for longer.

Defy Crystal clear deck sealer is not only kind to wooden exteriors but also kind to the environment. It is water-based so you do not have to worry about toxic fumes lingering in your space post-application. Being water-based also makes it easy to clean.


  • Environment friendly
  • Protects from UV rays
  • Protects from Fungi, mold, and mildew
  • Semi-transparent hence shows wood grain and texture
  • Water-based, easy to clean
  • Longevity


  • Multiple coats required which may be pricey in the long run.
  • Not enough shine.

5. Minwax Helmsman Spar Urethane

When it comes to protecting your woodwork, Helmsman Minwax protects from sunlight, rain, moisture, and temperature too, these are critical components when selecting the best outdoor wood sealers.  Its formula contains UV blockers that protect wooden surfaces from premature aging.  The wood sealer is waterproof and protects wooden exteriors from rain and moisture in general.

 It is also laced with protective oils that mimic the habitual expansion and contraction of wood offering maximum protection even during extremely hot or cold weather. 

The wood sealer is also easy to apply because it dries up very quickly. It has a medium viscosity and can easily be applied using a brush, roller, or sprayer. Helmsman Minwax offers a clear finish that highlights the grain on the wooden surface. This makes it pretty popular for use on light-colored wood and stained wood.

Minwax is versatile and apart from wooden exteriors and furniture, it can also be used on indoor furniture and surfaces like doors, windows, and cabinets. Its water-based formula makes it easy to clean.


  • Has utherane resins for clear outdoor finishes
  • Protective oils that adjust to the expansion and contraction of wood
  • UV blockers to protect from fading caused by sunlight
  • Resistant to mold and mildew
  • Waterproof protects wood from rain and moisture
  • Dry on touch
  • Easy to clean with warm water
  • Clear finish perfect for light-colored wood.


  • Some users say there is slight yellowing post application
  • Quite pricy.

6. Star Brite Golden Teak Oil Sealer

If your deck, patio, or garden furniture is made of teak or any other fine wood, then Star Brite Teak Oil couldn’t miss our list of best outdoor wood sealers. Star Brite Teak Oil is oil-based hence magnificent at waterproofing. It protects wood even from saltwater hence can be used on boats and pool deck areas. Apart from water and moisture, Star Brite Teak Oil also has UV absorbers that protect the wood from premature rotting and fading caused by sunlight.

Star Brite Teak Oil is very easy to apply. You can apply it using either a brush, a sponge, or even a piece of white cloth. After application, just wait for five minutes then dab the excess oil away and you will be left with a clean finish. Star Brite Teak Oil is famous for its warm golden finish which is excellent on fine woods.

Note, however, that the surface has to be scrubbed clean, rinsed, and left to dry before application.

Star Brite Teak oil may be oil-based but it is environment friendly. It is made from ultra-refined natural oils rather than chemical compounds hence causes no harm to plants or water sources. The ultra-refined oils also enhance protection from harsh weather.


  • Made from natural oils
  • Protects wood from saltwater
  • Offers UV protection
  • Easy application
  • Dries quickly.


  • It’s a bit pricy
  • Labor intensive prepping before application

7. Deck Premium Wood Stain

If you are shopping for the best outdoor wood sealers that are formulated specifically for softwood like cedar, pine, and fir which have been pressure treated, deck premium wood stain is your perfect choice. The water-based wood sealer is absorbed into the wood’s pores then forms a protective barrier. It is both waterproof and protects wood exteriors from UV rays inhibiting the growth of mold, mildew, and algae on the wood.

The wood sealer is semi-transparent and gives the wood a natural finish. There are four charming and tasteful finishes to choose from. These are:

  • Natural
  • Natural Walnut
  • Dark walnut
  • Cedar

Application is easy; all you need to do is clean the surface of your fence, deck, or patio and let dry then apply the sealer. Two coats are recommended; apply the first coat then wait 20-30 minutes before proceeding to apply the second coat. The stain and sealer is water-based hence routine cleanup with soap and water is enough.


  • Protects from UV rays, mold, algae, and mildew
  • Works as a stain/sealer
  • Can be applied to both damp and dry wood
  • Available in 4 different finishes


  • Works on a limited selection of wood
  • Low coverage per gallon

8. Rain Guard Concentrate Premium Outdoor Wood Sealer

The manufacturers of Rain Guard concentrate wood sealer put their money where the mouth is with a 10-year guarantee on this product. The guarantee makes it a favorite among woodworkers. Another advantage to the buyer is that the sealer is a concentrate that is mixed with one-part water to make twice the amount of sealer bought. Apart from it being among the cheapest products in the market, you still get twice the quantity at half the price.

Rain Guard concentrate wood sealer contains silanes and siloxanes that form a hydrophobic barrier which protects wood from water, moisture as well as freeze and thaw damage. The protective water-repellant layer also protects the wood from mold, algae, and UV rays maintaining the integrity of your wooden structure.

Rain Guard wood sealer is easy to use; just clean off dirt, dust, and debris from the surface using Rain Guard Prep Cleaner then apply the sealant.

The wood sealer does not form a film around the wood so you still get to see the grain of the wood. It is also made using no-sheen formula hence there is no yellowing of wood post-application.

Another plus for this sealant is that it is eco-friendly. If you need a sealant for your garden fence, this is a safe choice.


  • Inexpensive
  • 10-year guarantee
  • Non-toxic
  • Protects wood from UV damage
  • Waterproof and protects wood from mold and mildew
  • No yellowing of wood.
  • A transparent finish exposes the wood grain.
  • It can be applied using a sprayer.


  • Concentrate requires mixing which some users find cumbersome
  • Requires multiple coats.

9. Rust-Oleum Coppercoat Wood Preservative

Rust-Oleum goes beyond protecting wood from water and sunlight. With twice the amount of pesticide found in other sealers, it will keep your fence, deck, or porch safe from termites and other wood-boring insects. It also has twice the amount of fungicide to keep fungus, mold, and mildew at bay. 

The amount of fungicide and pesticide present in the sealant should not worry you because Rust-Oleum wood preservative is EPA approved. Rust-Oleum not only works on outdoor wooden exteriors; it has also been approved for use on below ground structures like basements.

Rust-Oleum does not alter the color of wood post-treatment. You may, however, notice a green hue on the treated wood surface. But that should not worry you because the hue will fade away after some time.

If you prefer you can still have the Rust-Oleum sealed wood stained or painted. Neither staining nor paining the treated wood will interfere with Rust-Oleum’s weatherproofing capabilities.


  • EPA registered.
  • Has insecticide to protect from wood-eating insects.
  • Does not alter wood color.
  • Paintable and stainable.
  • Has herbicide to protect from fungi, algae, and mold.
  • Protects from UV rays.

10. Cabot Australian Timber Oil Stain

Cabot Australian Timber oil stain is among our 10 best outdoor wood sealers because of its versatility. It works wonders on all kinds of wood from teak, mahogany, cedar, and including other high-quality woods. The dual function oil stain/ sealer can restore weather-beaten decks and fences to gleaming wood surfaces.

The oil-based stain is absorbed very fast and penetrates deep in the wood to accentuate the wood’s natural look while protecting its structural integrity.

Cabot oil stain also contains complex iron pigments that protect the wooden surface from sunlight by absorbing UV rays. It also contains pure South American tung oil that supports its water-repellent feature.

The application is simple, you only need to slap one coat of the stain sealer on your weathered wooden surface and transform it into a very appealing structure. Despite being oil-based, the stain sealer only produces mild fumes which makes it a joy to work with.


  • Iron pigments protect from UV rays
  • Has a toned translucent finish.
  • It is water repellant
  • Mild odor
  • Contains high-grade linseed oil for maximum penetration
  • Just needs one coat.


  • Beware of a modified water-based product with the same brand name but has a blue cap

If you have combed through our list of the 10 best outdoor wood sealers, you have some insight into what constitutes a good wood sealer. Our list only part of your shopping journey. Remember, different types of sealers offer different levels of protection. To get the maximum level of protection specific to your outdoor structure, check out the following wood sealer buyer’s guide to help you narrow down on what exactly you’ll need.

Factors to Consider When Purchasing The Best Outdoor Wood Sealers

  1. Outdoor use.

There are many wood sealers in the market. Some are better suited to work on furniture and interior spaces rather than on outdoor structures. Ideal sealers for outdoor space like fences, decks, patios, wood sidings, and gazebos should contain ingredients that protect from UV rays, water, and moisture as well as growth like fungi, algae, mold, and mildew.

2. Singe function Vs Dual Function.

Some sealers also double as stains. Sealers are meant to be absorbed by wood so that they fill in the pores and drive out air bubbles which when trapped in the wood facilitate rotting over time. Sealers are generally colorless. Stains have varying degrees of color and are used to change the appearance of wood.

If you need both a sealer and a stain you may save some money by purchasing a dual function product that is both a sealer and a stain. You can also consider the color options available for dual-function products. On the other hand, if all you need is a sealer just purchase a sealer that has no stain properties so that it does not alter the color of your wood.

If you opt to purchase a dual function stain/sealer it is worth noting that different stains have different finishes. There are three types of finishes namely opaque, semi-transparent, and clear. Opaque finishes last the longest but they obscure the texture of wood. They also tend to flake like paint. Semi-transparent finishes showcase wood grain and texture but last for a shorter period than opaque finish.

3. Water-based VS oil-bases.

The best outdoor wood sealers can either be water-based or oil-based. Each type of wood sealer is preferred by different users for different reasons. Water-based wood sealers are preferable among users for being less toxic, having less odor, and having a quicker drying time. They are however notorious for an undesirable cloudy finish. Oil-based wood sealers are preferable for their sleek glossy finish. They enhance the wood grain by darkening it and also give wood plenty of shine.

4. Weather and Climate.

The two arch-enemies of wood structures moisture and UV rays. The two cause wood to fade, rot, and also create an enabling environment for harmful organisms like fungi and mold. The more extreme the weather conditions in your area, the more susceptible your exterior wooden structures will be. You should opt for a very protective wooden sealer with a proven record on longevity.

5. Surface area covered per gallon.

Some wood sealers are a bit viscous and cover less area than expected. Others are a bit runny and require the application of multiple layers for a good finish. Apart from the size of your wooden outdoor structures, the above-mentioned factors will affect how much you need and hence your budget.

6. Type of Wood.

Different wood sealers work better on specific types of woods than on others. For instance, some sealers are formulated to penetrate dense woods like hardwoods while others are meant to penetrate lighter woods. The latter would not work on dense hardwood structures. If you find a sealer that is made for your specific type of wood, the better.

7. Eco-friendliness.

Some wood sealers contain an excessive amount of Volatile Organic Compounds (VOC). VOCs are emitted as toxic fumes during application and can cause harm to plants and animals, including you. Cover the plants around your deck or patio with a tarp when applying a sealer. You can also wear protective clothing like a face mask or goggles as a precaution.

8. Mode of Application.

Wood sealers can be applied using paint brushes, rollers, or sprayers. The consistency of the sealer can influence the mode of application. If the sealer is too thick you may not be able to use a sprayer. The viscosity of the sealer will help you select the brand of sealer that will best suit your mode of application.


  • What is a wood sealer?

Wood sealers are products meant to protect wood exteriors from damage caused by moisture, or even sunlight and organic compounds. Wood sealers are liquids with varying viscosity. They are applied on wood surfaces then penetrate the wood surface through the pores. Sealers work by expelling air from wood pores and hardening forming a clear protective layer around the wood. Lack of air in the wood prevents rotting. Wood sealers protect the structural integrity of the wood and lengthen its lifespan.

  • What is the difference between stains and sealers?

Sealers protect wood from the elements. They form a clear finish post-application. Stains are meant to enhance the color of wood. They can form either an opaque, semi-transparent, or clear finish depending on the type of stain. Some products are both stain and sealer mashed up into one product.

  • How long should a sealer last?

On average, wood sealers last somewhere between a year and five years. Various factors influence the durability of a sealer. For starters, the more extreme the weather conditions, the faster the wood sealer will wear off. The level of exposure also influences the lifespan of a sealer. For example, if a deck is exposed to direct sunlight throughout and has plenty of foot traffic it is likely to wear out faster than another deck located in a shady corner. The brand also matters. Some brands offer more durability than others.

  • How long does it take a wood sealer to dry?

That depends on the weather and the type of sealer. Sealers will take longer to dry in high humidity environments than in sunny areas. Other factors like penetration levels of the sealer and viscosity will also influence how long it takes to dry.

Thick sealers that penetrate deeper in the wood dry faster while runny sealers that stay on the surface take longer to dry up. As a rule of thumb seal your deck while the sun shines. The manufacturer can also advise you how long a specific brand should take to dry on average

  • How do I know how much sealer I need to buy?

On average, a gallon of wood sealer covers between 200-300 square feet of space. You should measure the size of your deck or any structure you intend to seal then do the math. Bear in mind that other factors like sealant viscosity and the number of coats you need to apply will also influence how much wood sealer you need to buy.


Wood may have lots of charm as a construction material but it is vulnerable to weather elements and will certainly require a facelift from time to time.  Wood sealers don’t just offer a facelift; they also protect the wood from rain, moisture, UV rays, and harmful organic matter.

Wood sealers are not standard; some have more value to offer than others.  Consider your needs carefully before deciding on the brand of wood sealer that will give you the best results both in terms of aesthetics and durability for your wooden structures. Our 10 best outdoor wood sealers should give you a great start.

Leave a Comment