non-pressure treated wood fence outside

Wood that has undergone a pressure treatment is more durable and less susceptible to decaying, infestation, mold, and even water damage. Non-pressure treated wood, however, is susceptible to all of these things and, therefore, will not last as long outside. That’s being said, you can still use non-pressure treated wood outside, but you will need to use some special measures to keep the wood protected.

Let’s go over the many different options available to keep non-pressure treated wood safe from the elements.

Threats to Non-Pressure Treated Wood

While there are several threats to untreated wood, the main two are the sun and water. All of these threats can reduce the lifespan of your wood or make it weaker, which can be a real problem, especially for a structure like a deck or a pergola.

The Sun

Ultraviolet rays can drain all the oil from wood, causing it to dry and crack. Over time, the wood will start to fade in color as the oil comes out. To combat the sun, place untreated wood in shady areas away from the sun. You can also cover the wood when it’s not in use. Also, you can stain or treat the wood, which we will go over below.


Whether from rain, snow, or water from a hose, water can cause wood to grow mold, decay, or rot in a short amount of time. Stain will not help to prevent water damage, but a sealer can. You can also use a waterproof cover sealed down against wind.


When wood becomes wet and it’s untreated, it can easily grow mold. Not only will mold cause the table to decay quicker, but it can also poison you, your family, and your pets. Stain can slightly reduce mold, but sealer works better.

Other Elements

Wind, insects, dirt, dust, and use can also cause untreated wood to die faster. Using stain and sealer can help to eliminate these issues as well as mold, water damage, and sun damage.

The lifespan of Non-Pressure Treated Wood Outside

At most, untreated wood can last about two years outside before irreparable damages occurs. Some wood can last up to five years but only in mild weather conditions. Depending on the type of wood, you could see it beyond damaged in a few short months. Meanwhile, pressure-treated wood can last for up to 15 years or longer.

Difference Between Treated and Untreated Wood

It’s easy to spot untreated wood outside as it often has a green tint from years of exposure. You can also look for a marking, which is used for treated wood. Finally, smell the wood, if it smells like chemicals, then it has probably been treated, while wood smells indicate untreated wood.

Types of Non-Pressure Treated Wood

Several species of woodwork better outside when not pressure treated than other woods. Some wood has natural chemicals that help to protect them from the elements. Softwoods include cedar, cypress, Douglas fur, pine, redwood, and spruce. You get more options with hardwoods, including teak, oak, mahogany, walnut, alder, beech, white oak, and maple.

Some woods will rot and weaken faster when constantly battling the elements. Pine should not be your first choice as it’s not capable of handling the weather without treatment. Softwood costs less, and it’s lighter in color and weight but only lasts ups to 10 years. Hardwood costs more, it’s darker and heavier but can last for several years and is naturally weather-resistant.

How to Weatherproof Non-Pressure Treated Wood

You have a few options available to weatherproof non-treated wood. First, you can use an oil like linseed or tung oil to serve as a protective coating, and it will help to make the wood look gorgeous too. Second, you can use varnish, polyurethane, or lacquer to finish the wood and essentially seal it from damage. Third, you can use semi-transparent deck stain. Fourth, you always have the option to paint wood, too, or even use epoxy. Finally, you can use a sealer.

Wood oils protect from rot, sunlight, and natural weathering. However, it will not last long and will need to be reapplied regularly.

Polyurethane or lacquer is ultra-durable and waterproof, making it an ideal option for untreated wood. You will need protective gear as polyurethane has VOCs, and the smell can last for a while. Also, it can take a while for polyurethane to dry and cure, up to a month!

Semi-transparent deck stain helps to preserve the beauty of your wood, and it dries quickly without VOCs or odor. It’s easy to clean too and can cover large areas easily. However, it does not last as long as polyurethane.

Paint lasts for several years, so long as you choose a high-gloss exterior paint. Look for an option that is waterproof, and you can paint pretty money anything with very little issue.

Epoxy is a polymer that resists liquid so it can prevent water damage. Use this after stain if you plan to stain. It can be messy, but you can apply multiple layers. It will take several days for epoxy to cure before you can use the wood.

Sealers are the best option because it locks the wood in a protective coating. Make sure the wood is clean and dry. Then use an exterior wood stain and sealer or just a sealer if you prefer. Use multiple coats for a better shine and longer-lasting finish.

Stain is not a sealer, it’s simply a treatment to change the appearance of wood. Meanwhile, sealers are usually clear and protect the wood without changing the color. If you want to change the color of your wood, use the stain first before using a protective coating.

Final Thoughts

You can use untreated wood outside; however, you need to take several factors into consideration. If you are not using treated wood, then you will want to protect the wood and keep it out of direct sunlight or areas susceptible to bad weather. Remember also that untreated wood will not last as long and will require more maintenance than treated wood.