When buying wood for outdoor furniture, you often hear talks of waterproofing or sealing the wood to protect it from the elements. Although wood can certainly be left untreated, there are a number of things you can do to protect the wood, allowing it to last longer.
Untreated wood can be used for small outdoor projects, but if you have big pieces, they will not last very long outdoors when the wood is untreated. The weather and sunlight will eventually damage the wood, and it will start to look weathered.
So, how long does untreated wood last outside? Natural weather conditions like sun, rain, snow, warm temperature, or humidity can cause a lot of damage to untreated wood. Depending on the type of wood you have and how resilient it is, untreated wood can last a few months to 2 years, at most, without any protection from paints or sealants.
Here are some elements that can affect your wood’s appearance and structural integrity when left to fend for itself in the great outdoors.
Why You Shouldn’t Leave Untreated Wood Outside
On the other hand, woods like Alter or Pine are absolutely not recommended to be left untreated outside. These types of wood are prone to rotting and decay, and they need an extra layer of protection. Otherwise, they can quickly deteriorate when facing sun, rain, and humidity for a long period of time.
Regardless of the type of wood, untreated woods will not last as long as treated woods when left outside for an extended time.
In general, untreated wood doesn’t last longer than 2 years outside with exposure to the elements, insects, and fungi, but some woods are more durable than others. Cedar, White Oak, and Redwoods, for example, are the best types of wood for outdoor furniture.
If you are using sealants on your outdoor furniture, it is also recommended to re-seal the wood once every 1-2 years. This is because the harsh outdoor conditions can eat away the sealants, so re-sealing the coat will reinforce the protection and allow your outdoor furniture to last longer. If you are looking for a sealant for wood, polyurethane is my favorite.
The main risks associated with untreated wood are rotting, insect infestation, and weather damages. Since untreated wood is prone to damage, it is usually not recommended to use it outdoors. Here are just some of the considerations when you use untreated woods outdoors.
1. Sunshine
Sun exposure can damage untreated wood because the UV light will gradually deplete the natural oils in the wood. When left under the sun for too long, untreated woods can become twisted or discolored after just a few months.
Generally, untreated wood should only be used in areas that can be safely avoided from direct sun exposure. However, the best practice is to seal the wood with a UV protectant and sealant, which will help you avoid warping and discoloration.
2. Humidity, Rain, And Snow
What do humidity, rain, or snow all have in common? Water. Water is a natural enemy for wood because wood is porous and can absorb water, causing the wood to expand. When the wood dries, it can shrink down, causing the wood to warp and lose its shape.
Waterproofing your outdoor furniture can greatly improve the wood’s ability to withstand humidity, rain, or snow. Coating your furniture with a few layers of a waterproof sealant – like epoxy, for example – can help your outdoor furniture resist absorbing moisture from the air or water from the rain or snow and improve the wood’s performance outside.
3. Rotting
But what happens when the wood is never completely dry? Wood rot can start when the moisture content of wood reaches 20%. If you live in a humid climate, this would be a perfect environment for fungi to slowly develop and eat away the wood. Molds can also develop in a moist condition.
Waterproofing your wood can help keep the moisture content of the wood below the 20%t threshold, which won’t allow an environment for fungi to develop.
4. Temperature
Drastic changes in temperature can also have a damaging effect on wood. The changes in temperature can actually change the humidity in the air, and subsequently, the moisture content in the wood, causing the wood to expand or shrink.
This problem can easily be solved by waterproofing your wood so that the changes in temperature and humidity won’t affect the moisture content of the wood.
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