How Long Does Pressure Treated Wood Last?

Pressure treated wood is lumber that has been treated with certain chemicals to protect it against the elements. This treatment process makes it last much longer than untreated wood, especially when used outside.

The lifespan of pressure treated wood depends on the use and the weather conditions. Fences and decking made from pressure treated wood will last 10-15 years, but some pressure treated wood can last as long as 40 years.

This blog post will tell you everything you need to know about pressure treated wood, how long it will last, and how you can keep it in good condition for longer.

Can Pressure Treated Wood Rot?

Yes, even though it is more durable than non-treated wood, it is still susceptible to rot. It will rot faster if not cleaned and maintained properly. The use of the wood also makes a difference and high-traffic areas like decking are more prone to damage.

What Causes Pressure Treated Wood to Rot?

Usually, mold and fungus are the cause of wood rot. Moisture will penetrate the wood and if there’s no way for it to escape, it will eventually get moldy. This usually happens over time so you might not notice the problem right away. The pressure treating will give the wood some protection, but there is still the potential for moisture to get into the wood.

Letting dirt sit on the wood can cause problems too. Damp soil brings fungus into contact with the wood and constant contact with moisture creates the perfect environment for it to grow in.

Does Pressure Treated Wood Need to Be Sealed?

Pressure treated wood does not need to be sealed as long as you maintain the wood properly. The treatment process is designed to keep out moisture and prevent rot. However, if you want added protection, you can use a deck sealer to seal the wood.

Can I Pressure Treat Lumber at Home?

No, you cannot pressure treat your own lumber at home. The process involves a lot of heavy machinery like vacuum chambers and also chemicals that are too harmful to be used at home. If you have untreated wood, you can seal it to prevent damage from moisture, but you won’t get the same level of protection that you could from professionally treated lumber.

What’s the Difference Between Pressure Treated and Non-Treated Wood?

Pressure treated wood has a greater resistance to rot and insects than non-treated wood. The chemicals used in the process strengthen the wood so it can better protect itself from moisture damage. Untreated wood, on the other hand, does not have the same protection and it will not last unless you treat it with stain and sealer.

Why Does Pressure Treated Wood Last Longer?

Wood is pressure treated by forcing chemicals deep into the wood’s grain using high pressure. The wood is put into a vacuum chamber, which removes all of the air and moisture from the wood. Chemicals are then added and the vacuum forces them deep into the cells of the wood. Different chemicals used include chromated copper arsenate or pentachlorophenol. These act to repel moisture and prevent mold and mildew in the wood.

How Long Does Pressure Treated Wood Last?

There is no simple answer here because it depends on what the wood is used for and how it is looked after. Some pressure treated wood can last up to 40 years if it is cared for properly and is not exposed to a lot of moisture or wear and tear. However, most pressure treated wood will get a bit more use, so it won’t last as long.

Pressure treated decking will last around 10 years, in most cases. With lots of people walking on it all of the time, and rainwater hitting it during the winter, it degrades faster than wooden fences posts, or sheds, for example. But if you take care of it and clean your decking properly, and consider covering areas in the winter, you can make it last longer.

Once the pressure treated wood starts to degrade and lose its protection, you should start looking after it in the same way that you would non-treated lumber. Refinishing and sealing the wood can make it last longer.

Is Pressure Treated Wood Safe for Decks?

Most pressure treated wood is safe to use for decks. The chemicals used in the process are not toxic and will not cause any health problems. However, it is important to check what kind of chemicals have been used to treat the lumber. In the past, CCA (chromated copper arsenate) was frequently used to treat pressure treated wood that was bought into contact with soil. However, it has since been phased out over concerns that it could be dangerous to people’s health.

Nowadays, ACQ (alkaline copper quat) is more common, which is supposed to be safer because it does not contain arsenic. CCA treated wood is still used for industrial purposes, but should not be used for decking.

How Long Does a Pressure Treated Wood Deck Last?

A pressure treated deck will last an average of 10 years, depending on how heavily it is used. But if you take care of it properly, you can make it last longer.

How Long Does a Pressure Treated Wood Fence Last?

pressure treated fence

A pressure treated wood fence will last around 15 years. It’s made to resist rot and insects, so it will last longer than other types of fences. But like decks, how long it lasts depends on the quality of the lumber and how well you look after it. It also depends on the climate where you live.

If you live in a particularly wet area and the fence is constantly hit by heavy rain and high winds, it will not last as long. Equally, strong UV rays can cause the wood to fade and split, so you may need to replace your fence more often if you live in a hot climate.


How Long Does Painted Pressure Treated Wood Last?

Pressure treated wood can be painted and this helps to add an extra layer of protection. Good quality exterior paint is designed to stand up against the elements, so your wood may last longer than it would otherwise.

However, it is important that you ensure the wood is fully dry before you paint it. Paint stops moisture from getting into the wood but it also locks it in as well. So, if your pressure treated wood is still slightly wet and you paint over it, you increase the chances of rot.

How Long Does Sealed Pressure Treated Wood Last?

Pressure treated wood can also be sealed with a protective coating. This will make the wood more resistant to rot and it will last for longer. Pressure treated wood is already protected from the elements, so sealing is not a necessity, but it can extend its normal lifespan.

Is Pressure Treated Wood Dangerous?

In the past, there have been concerns about the health risks from pressure treated wood. CCA is potentially dangerous, but wood treated with it is only used for industrial purposes and won’t be found in your home or garden. All of the pressure treated wood that is used for things like decking or garden fences is perfectly safe, so you’ve got nothing to worry about as long as you buy from a reputable supplier.

Can I Burn Pressure Treated Wood?

No, you absolutely cannot burn pressure treated wood and in many places, there are regulations to stop people from burning it. This is because the chemicals in the wood can cause serious health problems when they are released into the air. If you breathe the fumes from burning pressure treated wood, you may experience serious respiratory issues and even increase your risk of lung cancer in the future.

Check out this article to find out more about the potential dangers of burning pressure-treated wood and what you should do if somebody nearby is burning it.

Can I Sand Pressure Treated Wood?

sanding pressure treated wood

Yes, you can sand pressure treated wood but it’s important to be careful. When you sand wood, you risk breathing in microscopic wood particles, and the chemicals that are used to treat the wood. Always avoid sanding wood that has been treated with CCA because it’s incredibly toxic and not worth the risk.

You can sand wood that has been treated with less toxic chemicals, like ACQ, but you need to take precautions. Breathing in the wood particles can still harm your health, so make sure that you wear goggles and a good quality mask. Read this article before you sand pressure treated wood so you can make sure that you are doing it safely.

Can You Stain Pressure Treated Wood?

Yes, you can stain pressure treated wood. In fact, many people do it for aesthetic reasons because it often has a green color that doesn’t look great. Staining it is a simple way to make it look more appealing. You also add extra water resistance at the same time, so it’s worth doing. This guide will tell you everything you need to know about staining pressure treated wood.

Are There Alternative Options to Pressure Treated Wood?

Pressure treated wood is the best option for most outdoor projects because it will last longer, but are there alternatives? Well, you can use a sealer to protect untreated wood as best you can and it will protect it from the elements. However, this will need to be reapplied every year or two if you want to maintain the protection. Find out more about treating wood for outdoor use here.

Final Thoughts

Pressure treated wood can last up to 40 years in the right conditions, but if it is getting a lot of wear and tear, expect it to last around 10 to 15 years. However, looking after it properly and using a sealer can increase its lifespan.

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