Your deck is an extension of your home. But pressure-treated wood, while durable, can quickly deteriorate without proper protection due to elements such as moisture, wood rot, and fungal growth.
That’s where deck sealers and staining come in. We’ve rounded up the 7 best deck sealers for pressure-treated wood that will not only enhance the natural beauty of your deck but also prolong its lifespan.
Say goodbye to flaking paint and weathered wood, and hello to a stunning outdoor space that will be the envy of your neighborhood. Later, you may check these top deck stains.
Reviews: Top 7 Best Deck Sealers for Pressure Treated Wood in 2025
1. Thompsons Deck Sealer (Natural Wood Sealer) – #1 Pick
Thompsons Deck Sealer is an excellent deck sealer that’ll protect the wood from UV and mildew damage while also allowing it to keep its natural outlook (color). Luckily, you can do the sealing the same day that the wood is treated – that is after you also clean.
However, notices that the sealer is for exterior application only – particularly for pressure-treated wood but may use it for enclosed exterior porches or rooms’ sealing when you have enough ventilation – open the doors and windows and allow enough room ton dry.
Thompsons Deck Sealer will prevent mildew growth, water infiltration, and the harsh graying effect that could be attacking your press-treated wood in different projects, including decks.
So, apply a coat of this sealer, and you’re done worrying about damage to your wood projects. The deck stain, considering the varied opacities, will inject some pigment into your wood.
Besides sealing the decks adequately, Thompsons Deck Sealer will also be great on the exteriors of different wooden furniture outdoors, including fences, siding, and gazebos. You’ll find it’ll be easier to clean these surfaces once you apply the water-based wood sealer. Luckily, the sealer will dry very fast and hence simple to use.
Therefore, as noted above, Thompsons Deck Sealer is a water-based product you’ll find easy to use. Apply a single coat of the sealer, and it’ll protect the wood for long – going up to several years. With its waterproofing capability, the water beads falling on the wood’s surface won’t get deep into the pressure-treated lumber.
You can also do the wood-sealing project in 1 day, including preparing and applying the Thompsons Deck Sealer – both for damp or dry wood. The sealer is budget-friendly as you’ll only need to use one coat compared to other sealers and stains that need additional coats.
Water – generally, moisture – will be the most critical factor to cause rotting in your pressure-treated wood since parasitic plants, moss, algae, and molds feed and reproduce fast in such conditions. However, when misapplied, the sealer may leave some yellow tint on the furniture or wood.
- Suitable sealer for both dry and damp wood
- Easy and quick to use as you can finish the wood sealing project in just a single day
- Prevents damage of the pressure-treated wood by UV rays, fading, and mildew
- Requires just a single coat of the sealer for significant results
- Offers excellent water-proofing for the wood
- Longer lasting seal coat
- May leave yellow tint if applied wrongly.
- Slippery when starting
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2. Rust-Oleum 01901 Wood Sealer Copper-coat Wood Stain & Preservative – #2 Pick
Rust-Oleum Sealer is an excellent treatment for your pressure-treated wood – it’s also easy to use as you’ll complete the preparation & application in just a day. This is because the sealer will dry in just 4 to 6 days, and thus you can use the wooden piece within one day. It contains powerful preservatives – copper naphthenate (9.0 %) to hinder wood rot.
Rust-Oleum Sealer also comes semi-transparent suitable to treat for cedar siding. But I would recommend using the blue shade as it’ll last longer and it’s equally beautiful (this is my personal opinion) on cedar fences (and others), but this might not work on shingles.
Despite that, the product label doesn’t put it; clearly, Rust-Oleum Sealer is water-based and highly toxic and will work well as a pesticide and preservative. However, if the sealer lands on your skin, you’ll only need to clean it off using water and soap.
Rust-Oleum tops among all the sealers to create a long-lasting and beautiful durable coating. I would say that the layer from this sealer is 18 times thicker compared to other regular paints. Therefore, it’ll easily prevent rotting and also protect your wood from damaging weather conditions.
Rust-Oleum sealer comes in a range of colors – more than 60 colors to choose from, and hence it’ll be an easy task to restore the look of your composite decks surface, wood decks, and weathered patio regardless of color and current fade. You might not require elaborate preparation – thus, no excessive washing, stripping, and pressure sanding.
So, the Rust-Oleum sealer provides better water resistance, excellent adhesion, and adequate waterproofing to your wood. Further, it’ll readily fill up the ¼-inch deep cracks and wood defects to give you an ultimately beautiful and smooth finish. It’s also budget-friendly as one gallon will treat (using one coat) 160 square feet.
I noted that the sealer is designed to help extend the life of your wooden fence posts – particularly those that are pressure-treated to mainly protect them against all the wood-boring insects, including ants so that it’ll serve you for longer.
Rust-Oleum sealer is very consistent (oil-like), and thus you’ll find it simple to use the brush to seal and treat the wood grains to give the pieces a green tone. However, only use the sealer on the exteriors only because it has a very pungent smell – but here’s a step by step guide on how to remove the spray paint smell.
- Comes in a wide range of colors – over 60, to be specific
- The sealer will be useful when you apply a single coating.
- It’ll fill up crevices and cracks that measure up to 1/4 inches deep.
- It’s weather-resistant (including against snow and rain), and it’s also water-proof
- For high coat durability, Rust-Oleum sealer is designed to be 20 times ticker than regular paints
- May be overly thick to use for some painters
3. CabotStain 140.0003400.005 Wood Sealer Natural, Quart, Oil – #3 Pick
Cabot Wood Sealer will give your wood a quick coat – particularly some golden glow, including for your pine that’s cheap and sun-baked. It’ll adequately seal and protect (from UV rays and mildew) your split rail fencing, decking, and outdoor wood and furniture.
Cabot stain is an Oil penetrating sealer for your wood that contains iron-oxide that’ll protect them against UV rays damage – even for the very dense kind of woods. However, avoid the ‘modified type’ of this sealer since it won’t get readily absorbed and may form a cream on the surface.
I’ve used CabotStain sealer for very weather-damaged wood, fence posts, and decks that had not been repaired for a long time. Notably, contractors had insisted that we replace the deck, but finally, I realized that the pressure-treated wood was still structurally okay; only the cosmetics were missing.
With CabotStain, you’ll only require to power washing and sand (with sanding blocks) your wood or deck – this will help remove most of the stain on the surface. However, I also used a wood-grain filler for the crevice, gouges, and cracks that went deep into the pressure-treated wood – this would make the wooden pieces extend their lives.
The sealer will readily penetrate very dense wooden surfaces varying with the surface porosity – its seal about 250 to 600 square feet of wood surface for the irregular to smoother exteriors, respectively. It gives your wood that natural look and has a deep penetrating formula that’ll also protect against the sun’s UV rays.
- Suitable sealer for weathered and old wood, including deck
- Will adequately seal premium wood like teak and mahogany.
- Has a oil deep-p
- Won’t protect against UV rays but you can add
4. DEFY Wood Sealer (Crystal-Clear) Deck Water-proofing Sealer – #4 Pick
DEFY Wood Sealer is a water-based wood sealer that can also be used for your deck. The environment friendly will give your pressure-treated wood a natural look and protect it against UV rays and mildew and allow the wood to last longer.
DEFY Wood Sealer is a very durable wood sealer that’ll give the surfaces a clear finish. Further, it’ll also protect the pressure-treated wood from UV radiation, fungi, and water. Notably, the Sealer contains zinc nano-particles that’ll prevent the development of fungal growth and algae stains.
However, you’ll need first to use a deck cleaner that’ll help clean up the treated wood surfaces – and only seal the wood surfaces that have started graying. It is suitable for natural wood surfaces and composite decks, leaving the wood with some crystal-clear finish.
DEFY Wood Sealer will effectively treat your old fence posts and any weathered deck (composite) to restore their natural and fresh look – to last longer. The sealer is made from quality resins that’ll help your wood resist darkening and fading further – allowing the sealer to last for more seasons.
I also noted that DEFY Wood Sealer wouldn’t harm your eon or TREX decks; it’ll treat them effectively. But you’ll also need to power-wash the pressure-treated wood or deck before applying the durable DEFY Wood Sealer – it’ll dry, leaving a natural and fresh look.
- Zinc nano-particles enhances protection against UV rays and staining from algae and fungi growth.
- Prevents graying and black stains
- Created from superior resins
- Protect the wood against mildew
- Suitable for composite decks and sealing even dense hardwoods
- None
5. THOMPSONS Wood WATER-SEAL ( Transparent Stain) for Wood-land Cedar
Thompsons Wood Water-Seal is a transparent stain that’ll protect your pressure-treated wood from damage by mold, rot, mildew, as it’ll waterproof its exterior surfaces. Luckily, this sealer also tends to dry fast, and it’s equally easy to use.
Thompsons water-seal will be great for exterior wood treatment – it has superior polymers that’ll offer better and longer protection against wood fading. This will work great for both damp and dry wood, protecting from UV radiation and mildew damage.
Thompsons water-seal, when applied, will show the wood grain of the pressure-treated wood to provide a fresh and natural look and texture. You can use a sprayer, roller, and brush – this is suitable because it’ll dry within a short time after application.
The sealer can also provide a waterproof coating to protect the pressure-treated wood from water damping after the first water beading is finished. After cleaning & rinsing the deck, you can now spread the sealer on the wood or patio with oxalis acid.
Thompsons water-seal is thick and comparable to thick paint, and hence it might be challenging to apply the sealer using a sprayer but can be used anyway. However, I am happy that the sealer will work just well with just a single coat, making it very budget-friendly.
The sealer won’t require more than a single coat – comparatively, other regular stains and sealers require applying 2-3 coats for effective wood treatment. It’ll revive and restore any of your weather-beaten or old wood – it’ll also dry very fast (within 2 hours).
Thompsons water-seal will made it comparatively easy to restore and maintain the deck. Further, this sealer will eliminate any impurities, sand and stains from your pressure-treated timber (with different benefits) and thus reduces the need to regularly apply a finish on the wood – even for up to 2 years.
- Creates a natural look and texture on the pressure-treated wood that’ll allow you to see through
- Suitable to seal both damp and dry wood
- Can be used as both a sealer and stainer – which makes it very cost effective and easy to use
- Requires through mixing
Conclusion
Luckily, the wood sealer will protect the decking and guard rails with one quick sealer coat using just a simple brush plus some wood-filler if needed for your circumstances.
CabotStain sealer is excellent for premium wood varieties, including teak and mahogany.