How Long Will Non Pressure Treated Wood Last Outside

In the open, non-pressure-treated wood can endure anywhere from 5 to 10 years, depending on climate, exposure to the sun, and other factors.

Depending on the climate, untreated wood can live as little as five years with poor management. On the other hand, protection and upkeep can extend the lifespan of untreated timber too well beyond ten years.

Pressure-treated wood, on average, has a service life of roughly 15 years when exposed to the outdoor. This info is useful when you intend to put furniture to decorate the outside area.

Pressure-treated lumber vs. untreated lumber

Pressure-treated wood contains chemical preservatives at a precise pressure and temperature conditions. It is the fundamental difference between the two kinds of wood.

Untreated wood, on the other hand, is still in its original form with no external modification.

It will rot when exposed to water or moisture because the water will permeate its pores. In addition, the sun’s UV rays can cause wood to fade in color. Some insects may eat it as well.

Non-pressure treated wood can always be treated topically to make it suitable for outdoor use. Moisture, insects, and sunlight can all be prevented by applying these topical preservatives to the wood.

How to Tell the Difference

Many kinds of treated wood have a seal or mark that shows they have been treated.

When wood is treated with pressure, it often gets a slight green tint. If your wood is light green, it is likely treated with pressure.

Just by smelling the wood, you can tell if it has been treated or not. Wood that hasn’t been treated will smell like the outdoors and have a natural scent, while treated wood will smell like chemicals.

Advantages of Using Untreated Wood

You might think that since there are so many ways for untreated wood used outside to get damaged, you should use treated wood instead.

Many like untreated wood’s natural look and smell and use it in their woodworking projects.

There are many reasons to use wood that hasn’t been treated:

1. Toxicity Levels

Chemicals keep treated wood in good shape, but untreated wood doesn’t have any of those chemicals. Using treated wood without the right safety gear made it very dangerous.

Untreated wood is still much safer than treated wood since you must wear a dust mask, glasses, and gloves when working with treated wood.

It can be used on any project without risking the woodworker’s health.

2. Gardening Projects

Since untreated wood doesn’t have such chemicals, it can be used for gardening projects, like building a garden bed without worrying about hurting the soil.

3. Affordability

Copper, which is more expensive, started being used in more recent ways to treat wood.

Because of this, the price of treated wood has increased significantly, while untreated wood has stayed much lower.

4. Fewer Health Concerns

When you use wood that hasn’t been treated, you don’t have to cover your skin and eyes out of fear of getting hurt.

To avoid breathing in sawdust, always use a dust mask whether working with treated or untreated wood.

However, there is no doubt that working with untreated wood is safer for your health.

The dangers of using unpressured wood in outdoor applications

The wood receives exposure to various weather conditions if you utilize non-pressure treated lumber for outdoor applications without applying treatments.

The Sunlight

The sun’s UV rays are responsible for harmful radiation.

Untreated wood is exposed to harmful rays, which could cause it to fade. Once the oil is gone from your wood structure, it will lose color and all of its color.


Water is the greatest threat to untreated wood exposed to the elements.

Water, whether in the rain, snow or any other form of precipitation, may do significant damage.

Insect damage

Termites and other bugs that eat wood can quickly damage your valuable untreated wood if you leave it outside.

Wood that hasn’t been treated is open to attack and can be low-hanging fruit for termites in your garden.

Reduced lifespan

All the weather conditions outside that break down the wood’s structure eventually shorten its life.

This is why wooden furniture that is treated well and kept in good shape will last longer than one left outside without being treated and kept in bad shape.

Discoloration from molds and mildew

If you leave untreated wood outside, you may notice black stains forming on furniture surfaces or other wood items. They are fungi that appear due to the wood surface’s high moisture level.

Dust and water are what molds and mildew need to grow and spread. These fungi can live with just a little dust and water from the air.

Once mold starts to grow, wood rot is always right behind it, waiting to cause decay and permanent damage to the wood.

How to treat untreated wood for use outside

Using wood that has not been pressure-treated outside should not deter you from doing so. Everything is as simple as sealing the wood, which may be done in various methods.

  • When cleaning with water, the grain of the wood is frequently raised. You should see some roughness in the finish once the wood has dried.
  • Sand the surface until it feels smooth using sandpaper. Depending on the job, the type of wood, and the sealant, you can use anything between 180 and 220 grit.
  • Apply the sealant to the wood when the wood has dried completely, following the label’s instructions. Ensure you follow all the instructions in the booklet before applying the product.

Wood Sealers

Sealants for wood are often composed of some plastic or acrylic composition.

After that, this mixture is poured over the wood and left there to soak.

When it dries, the wood will have a plastic coating on the inside and the outside of its surface.

Oil Finishes

Most oil finishes for wood are made from either linseed oil or tung oil.

Even though they don’t soak in as deeply as other materials, these oils get into the wood grain. Still, they will make a waterproof surface, which is the point.

Stain-Sealer Combinations

There are a lot of products that come with both stain and sealer in the same package.

If you were already going to do these two things, you could save time by doing them all at once.

Coatings made of polyurethane tend to yellow and fade over time, making the wood look older than it is.


Varnishes are often made of polyurethane, which is also used to make sealers, and it builds up layers of a waterproof coating to make a hard outer layer.

This will work like a shell that keeps out unwanted moisture and absorbs shocks without denting the wood itself.

Pressure Treatment

The wood is soaked in preservatives by subjecting it to a combination of hot water, pressure, and many different preservatives.

The pressure is forced deep into the wood grains, which eliminates any possibility of rot occurring on the inside.


When you are directly applying epoxy, it results in the application of an optimum protective coating that drives all water away.

This is because epoxy is quite thick and helps keep the wood from getting damaged by water or damage on the surface.

But keep in mind that epoxy is not resistant to ultraviolet light so it will lose its color after some time in the sun.


Painting untreated wood has traditionally been considered the best way to prepare it for outside usage.

Paint is not the best choice for you because it can hide your original design and will cover it up with a color of its own if you use it.

Paint is an excellent choice for specific projects, including wooden flower pots, wooden boxes, outdoor chairs, outdoor tables, outdoor fences, and many other materials.

What kinds of untreated wood can you use outside?

Few kinds of untreated wood can endure the elements without the need for pressure treatment. Natural compounds in the structure of certain wood species often make them weather resistant.

The species of wood determines the longevity of untreated lumber. No matter how good a sealant is, some woods cannot be protected as well as others.

There are several common kinds of wood, but some of the hardest and most weather-resistant are teak, redwood, cedar, cypress, fir, and white oak.

When left out in the elements, untreated redwood can last up to 50 years, depending on its age. It is estimated that the lifespan of pine variants will be between five and ten years.

To get the best of both, use cedar as a substitute for pine or fir, which have a 15 to 20 years life expectancy. The price is quite affordable, especially when you buy large amounts.

1. Cedar

Cedar can naturally fight off insects and natural decay with the help of water.

Cedarwood is easy to find and, because it has a straight grain and stays the same size, is often used for things like fencing, decking, and trim that work best with brittle wood.

2. Redwood

Redwood is known for being strong and able to protect itself from the elements by making chemicals on its own.

The problem with redwood is that it is hard to find because of rules that protect the bigger and older trees. This has led to less redwood lumber being made.

3. Cypress

Cypress wood works best outside in hot, dry climates. This type of wood is quite stable and does not splinter readily; therefore, it may be utilized for various purposes.

Cypress isn’t too resistant to rotting, but it’s not even close to Cedar or Redwood in terms of how well it keeps things from going bad.

4. Teak

In many places worldwide, teak was the wood of choice for making boats. It naturally has a lot of oil, which makes it resistant to water, rot, and decay. Additionally, teak wood naturally resists termites and various other insects.

5. Douglas Fir

Douglas fir isn’t just a nice-looking type of wood. It is often used for porch decking and other outdoor projects because it is strong and doesn’t rot or attract bugs.

It doesn’t change size much and has few knots. As all wood products do, it grows and shrinks in response to moisture, but it does so evenly. It probably won’t buckle and warp, especially if you choose clear vertical-grain products.

6. White Oak

White oak is an excellent choice for any outdoor project since it is both appealing and durable, with a close-grained structure that makes it practically impervious to water.

Additionally, it has a high resistance to decay and is even utilized in the construction of boats.

How long do untreated pine and oak last outside?

When left outside, only five to ten years are expected from various pine types.

Compared to untreated redwood, which has a lifespan of 50 years or more when exposed to the outdoors, this is a pittance.

If the soil is moist and the oak is in direct contact with it, it can persist for 15 to 20 years. However, if left in a dry location, oak trees can live for up to 50 years if kept above ground.

You can extend the life of the wood by coating it with Tung or linseed oil. Seal it with polyurethane, varnish, lacquer, or stain-sealant mix.

However, even if you use weather-resistant wood outside, it will eventually degrade. You may try water-repellent preservatives or exterior-grade paint to ensure it will withstand the elements.

How To Seal Untreated Wood?

If you didn’t want to use treated wood for your project, you would need to seal and finish the wood to make it last longer.

Find the best stain and sealant for your needs. The sealing process is hard, but it’s worth it because it will make your projects last longer.

Before you decide if you want to seal untreated wood, you should carefully look to see if it is decaying or rotting.

If it is, sealing it might not do much to save it. But if everything looks good, you can be sure that sealing will do great things for the health of your wood.

Step 1: Cleaning

The first step in sealing wood is to clean it and make sure it is scorched so that no dirt, grime, dust, or moisture can get inside the sealed wood.

Using air dry makes sure that your wood is completely dry.

Step 2: Choose a wood sealer

You can choose from many different products, and most woodworkers disagree on which one is best.

Lacquer, shellac, polyurethane, and varnish are the most common types of sealant. Depending on the type of wood you are using, each has its benefits.

Step 3: Coating

Using a regular paintbrush, you can put a single coat of sealant on the surface of your wood. After that, you should let it dry again.

Once the first layer is completely dry, add a second layer and let it dry again. Make sure to wear gloves and only add a thin layer each time.

Once the wood has dried for the last time, sealing it will make it more resistant to the weather for a longer time.

How to use non-pressure treated wood furniture outside

Non-pressure-treated lumber exposed to the elements has several dangers that can be mitigated with a few simple precautions. Using untreated wood outside is safe if you follow a few tips.

  • Wood deterioration and rot are primarily the results of water exposure. Wipe away spills immediately or cover the wood with fabric to prevent rain from falling on it to avoid this risk.
  • Wood types have a direct effect on how long untreated wood lasts. Some woods can’t be protected as well as others, even with the best sealants.
  • Chemicals can be used to keep it safe. Sealing your wood with UV-blocking topical substances is the best way to keep it protected.
  • If you have non-pressure-treated wood furniture, you can bring it indoors during the fall or winter months when you do not use it.
  • Do everything you can to keep wood out of direct sunlight.

How long does pressure-treated wood last?

Pressure-treated wood has a 40-year life expectancy.

Depending on the type of wood, the intended usage, the maintenance required, and the climate, this lifespan could be increased or decreased. Pressure-treated lumber can endure up to 70 years before showing any deterioration or rot with further protection.

Regarding fences and decks in landscaping, pressure-treated wood has long been the material of choice.

It’s hard to say how long pressure-treated wood will last, but keeping it in good shape can make it last longer.

When To Use Pressure Treated Wood?

All outdoor projects should use wood treated with pressure unless the wood is naturally resistant to bugs and rot. Not every pressure treatment is the same.

You should use pressure-treated wood at least 6 inches above the ground for outdoor projects like deck railings, fence pickets, porch flooring, joists, and beams.

Ground-contact wood has a higher concentration of chemicals that keep it from decaying and rotting when it comes in contact with soil, plants, rain, moisture, or other things that can cause that.

It should be used when the wood will get wet often and not have enough time to dry, when there isn’t enough airflow, or if you live in a tropical area.

They are used to make garden boxes, landscape walls, wood foundations, and structural posts.

What can be done to stop wood from rotting underground?

You can stop the wood decay by soaking the base of the post in a preservative made specifically for wood. If you do this, the wood won’t rot away over time.

Treat the post before burying it. Keep copper naphthenate preservatives in mind; the bottom must be at least 1 foot below ground.

Choosing the proper wood is the first step in preventing fence post rot. Heartwood, mahogany, cedar, and redwood are all available for selection.

Because of this, pressure-treated timber is less expensive and lasts longer than lumber made from heartwood or the tree species discussed before.

To keep the posts from decaying, fence builders will inform you that there is a guaranteed technique. They recommend installing gravel and concrete.


It is risky to expose untreated wood to the elements without first protecting it, as doing so can dramatically shorten the lifespan of the wood.

It is possible to utilize lumber that has not been treated with the pressure outside if the wood is coated with protective oil or if it is treated with a suitable outdoor wood sealer.

This sealer will assist control any surface splitting or cracking, making the surface look more appealing.

Frequently Asked Questions

Scroll to Top