Pressure-treated wood is a building material that has been infused with chemical preservatives to make it more durable and prevent rot, mold, and harmful insects. They invented this method of treatment because any wood that is in contact with the ground or moisture for long periods become enticing for insects and speed up natural decay, so untreated wood may only last a year or two. Because of this pressure-treated wood is one of the most popular materials used for deck building, that's why we went ahead and made a complete guide on this topic to answer all of your questions.

How is Pressure Treated Wood Made

pressure-treated wood
Pressure-treated wood deck assembled

You may be wondering how do they make pressure-treated wood to have all those benefits. To start, pressure-treated lumber is wood that has been immersed with chemicals and placed in a pressure chamber that sucks the air out and forces the chemicals into the wood fibers. This way guarantees that the chemicals make it to the core of each piece of lumber. This method is extremely effective compared to just soaking the wood in chemicals. The most common chemical used in residential settings is MCA (Micronized Copper Azole). The use of this chemical especially copper helps keep insects out and fungi at bay. Since the chemicals can be also harmful to humans, when working with pressure-treated wood it is always smart to wear gloves, avoid breathing in sawdust, and do not burn any wood that has been treated

How to Tell if Wood is Pressure Treated

The two easiest ways to tell if the lumber has been treated are an end tag and a stamp on the piece of wood in question. The tag should be at the end of each piece of lumber and should mention the preservative used, the rating, and the preservation company. In addition to the tag, there should also be a stamp on the piece of wood. This stamp will tell you the type of wood and where it should be used.

Example of the tag

pressure-treated wood tag
An example of the end tag for pressure-treated wood

Example of the stamp

pressure-treated wood stamp
An example of the stamp for pressure-treated wood

How Long Does Pressure Treated Wood Last

This is one of the most common questions regarding pressure-treated wood and the answer is... It depends! The most important factors to consider are the climate, the type of wood used, and how well its maintained year over year. Typically treated wood well maintained can last up to 30-40 years without rot or an insect infestation, but if you don't properly maintain a pressure-treated wood deck and it is exposed to freeze-thaw and/or wet-dry cycles then it might only last 9-10 years before problems arise. Regular maintenance is the most important thing you can do to preserve your beautiful deck. Removing snow during the winter and trimming grass/keeping plants away from your deck will allow the wood to dry out easier and increase drainage during rain.

Can I Stain or Paint Pressure Treated Wood

The answer is yes! You can paint and stain your pressure-treated wood deck but it is very important to remember that the wood is completely dried before you paint or stain it. This can take weeks or months, and you'll need to make sure all water has been absorbed by the deck. We also recommend using a latex primer and water-based paint

Cedar Wood vs Pressure-treated Wood

Before the end of this article, I want to compare a very popular building material to pressure-treated wood, cedar. Cedar wood is nature's pressure-treated wood. It's already decay and rot resistant, the acids, and oils within a cedar tree give the lumber the properties of pressure-treated wood. Compared to pressure-treated wood, the main disadvantage to cedar is the cost to buy the lumber. So, your budget will need to be much higher when building a cedar deck versus a pressure-treated wood deck.


Pressure-treated wood is a great choice for deck building. It's durable and looks beautiful. As long as you maintain it properly, you will have a wonderful deck to enjoy for years to come