Deck Sealing vs Staining: What’s the Difference?

A sealer for a wooden deck is not the same as a stain, even though they both will protect the wood from the elements. It’s the differences, however, that determine whether it’s a deck sealing vs. staining task.

A sealer goes on clear or transparent to show the grain and the natural wood color. It prevents water from being absorbed and causing rot. Whereas a stain will do much the same as a sealer but also has a pigment added that blocks UV rays that can dry out the wood, causing it to crack or check, and gray.

In this article, we’ll look at what a deck sealer and stain are, their different types, some pros, and cons, whether you need to seal or stain a deck, plus what the best product is. By the time you finish reading to the end, you should have a better understanding of what a deck sealer and a stain are, and where and when to use them.

What Is Deck Sealer

Deck Sealing vs Staining

A deck sealer protects wood from moisture, precipitation, insects, mildew and mold, and rot. Most sealers go on clear and dry clear, showing off the wood grain. However, they don’t have a pigment to protect against wood graying UV rays and sun damage. The sun can dry the natural oils found in wood, causing it to gray, dry out, split, crack, or check.

Water will bead if the wood is sealed. Otherwise, it’s difficult to tell if there is any sealant on the wood. If it doesn’t bead or is quickly absorbed, it needs to be sealed. Deck sealers aren’t just for decks. They can be applied to horizontal and vertical wooden surfaces and structures, and even outdoor furniture. A sealer is ideal for cedar, teak, and mahogany where seeing the natural color and grain are important.

There are different types of sealants for decks. They differ depending on their use and the material they are designed to protect.

Penetrating Sealers

Penetrating sealers like Tang oil, Linseed oil, Hemp oil, and waxes (natural or synthetic) mixed with mineral spirits or vinegar are finishes that go into the wood grain to enhance it and bring out the wood luster; ideal for teak, cedar, and mahogany railings and furniture. It can be hand-rubbed into the wood or painted on with a brush or roller.

They soak into the grain and offer protection against moisture and weathering. When required, a new coat can be applied without sanding or stripping. Areas that wear faster can be touched up without redoing the whole deck too.

Coating Finishes

Coating sealers provide a harder surface finish and protect the wood from moisture and are more scratch-resistant. Shellac, lacquer, and varnish take longer to dry and are susceptible to cracking and peeling. Spar varnish is a more water-resistant sealer and is often used on ship decks and other woodwork.

Modern wood sealers are more durable than shellacs and lacquers. There are a variety of modern wood preserving sealers available. They protect against bugs and mildew and even offer UV protection while enhancing the wood grain; all protect against moisture.

  • Water-based sealers are absorbed into the wood grain and seal out moisture when they dry.
  • Oil-based sealants absorb into the wood to protect against moisture, rot, and mildew.
  • Acrylic resin-based products soak in and bond to the wood fibers.


  • Leave wood the natural color
  • Naturally repels water
  • Protects and preserves wood from natures elements
  • Extends life of surfaces and structures


  • No UV protection so wood grays or fades
  • Wood can dry out and crack, split, or check
  • Has long drying time

What is Deck Stain

Stain or seal deck

Deck stains protect the wood from moisture, precipitation, rot, mold, and mildew. They also have a color pigment or tint added that prevents wood from graying due to UV rays and sun damage. Deck stain is similar to deck sealer, except it offers more protection from the sun, minimizing the graying of the wood.

Stains are water or oil-based and range from semi-transparent to opaque, with darker, more solid colors offering better UV protection. A stain can enhance the color of the wood and provide a more consistent pallet. The stain will fade over time and should be reapplied every 2 to 5 years as required.

For the best results with deck stains, the wood should be completely cleaned and dry. Deck stains on horizontal surfaces will need to be reapplied more frequently than those on vertical surfaces.

  • Wood Toner is almost clear with a hint of wood tone or color – cedar, teak, mahogany, and oak – to slightly color the deck boards in a more uniform or desirable tone. It needs to be reapplied yearly.
  • Semi-Transparent allows the wood grain to show through while noticeably adding the desired color. It will last 2 to 3 years between applications.
  • Semi-Opaque or semi-solid hides most of the wood grain beneath the rich pigment. It should be repainted every 3 to 4 years.
  • Solid Stains (Opaque) has the richest color and hides the grain the most. It is good for 4 to 5 years.


  • Last up to 5 year
  • Rot, mold and mildew resistant
  • Protects against UV and sun damage
  • Multiple color and tint choices and hides wood discoloration


  • Surface to be stained should be washed and let dry
  • Hides wood grain
  • May take multiple applications to get desired tone or color

Deck Sealing vs Staining

Deck stain vs sealer

A deck sealer is a clear or slightly tinted water or oil-based product. It soaks into the wood grain, sealing it to prevent moisture damage, mold, mildew, and rot. Additionally, some products have additives to protect against UV rays and sun damage. Sealing a deck is best for cedar, teak, mahogany, or other quality woods as it enhances the wood grain and natural color.

Staining a deck protects the wood from mold, mildew, moisture, and rot, and UV rays and sun damage. The stain is available in transparent, semi-transparent, semi-opaque, and solid colors. The thicker the color, the more UV protection it provides. Staining also makes the wood grain less visible, which is ideal for protecting spruce, pine, fir, plywood, OSB decks, fences, and other surfaces.

Do I Have to Stain or Seal My New Deck?

Untreated and pressure-treated wood that is exposed to the elements will dry out, crack, split, twist, and discolor. Some wood has natural oils that protect them and will last a bit longer. Once the wood dries out, it is easy for insects, mold, and mildew to damage the wood. The dry wood is also susceptible to moisture damage and rot. The longer you wait to seal or stain your deck, the more damage to your investment.

Sprinkling a small amount of water on the wood is a good way to check if it is ready to be sealed or stained. If the water beads, the wood isn’t ready, but if the water is soaked into the wood, it is ready to stain or seal – a good indicator for pressure-treated wood that often ships wet. Wood that absorbs water will absorb stain or sealer for a better bond.

Sealing helps to maintain the color and smooth surface of the wood. The longer you wait, the more faded the wood will become, and the more ‘furry’ the board surface. New decks constructed of pressure-treated or SPF timber should be stained or sealed as soon as the water stops beading.

Staining a new deck will provide a more uniform color or tone to the wood, while sealing will help maintain the natural color. However, wood that is sealed will still fade over time but will continue to show the natural wood grain.

Do You Need to Seal Wood After Staining?

Adding a sealer over a stain isn’t advisable. The stain will protect the wood the same as the sealer. However, since the stain has already sealed the wood grain, the sealer won’t penetrate, or penetrate well, and will peel and flake. Adding stain over the sealer will have the same results.

Best Deck Sealer

wood deck sealThompson’s WaterSeal Advanced Natural Wood Protector makes short work of protecting your deck. It brushes, rolls, or sprays easily onto clean damp or dry wood; however, a brush is recommended. The clear liquid penetrates the wood to seal against moisture damage, insects, mildew, and damaging UV rays.

The waterproofing liquid dries clear, leaving the wood color and grain visible, helping to prevent graying and fading. It is ideal for new and older decks, outdoor furniture and structures, buildings, and fences. Works well on cedar, SPF or pressure-treated timbers.

It requires one application, and in most environments, will last for two years. One gallon will cover about 200 ft², and clean-up is a breeze with soap and water.

Best Deck Stain

deck wood stainThompson’s WaterSeal TH.041811-16 Transparent Waterproofing Stain is available in five colors: Harvest Gold, Acorn Brown, Maple Brown, Woodland Cedar, and Sequoia Red. The advanced polymer formula resists fading and water damage. It provides a uniform tint to pressure-treated or SPF lumber and will enhance the color and luster of cedar decking.

Thompson’s Stain protects wood from mildew, moisture, and UV damage. It can be applied to clean dry or damp wood and dries in approximately 2-hours. Although application by brush is recommended, a roller, paint pad, or sprayer will work too.

Clean-up is also easy with soap and water. The stain will cover between 150 to 400 ft² and last up to 3-years on horizontal surfaces and 4-years on siding and fences.


Deck sealing will protect the wood from splitting, cracking, moisture, mildew, and rot while maintaining the color and grain of the wood. A stain will protect the wood and provides a more uniform tint or color to the wood to complement surrounding structures. The more solid stain also minimizes the effect of UV rays and sun damage.

Hopefully, you have a better understanding of deck sealing vs. staining, what they do, and what will protect your deck better. If you found this article of value, please share it with others. Your comments and suggestions are always appreciated.


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