What is Pressure Treated Wood?

A very disheartening thing about using wood as building material or for furniture is that it’s no stranger to rotting. Wood can also harbor insects which can destroy and corrode it.

How do you enjoy the natural beauty of wood without worrying about pests and rotting?

The answer is using pressure treated wood. Pressure-treated wood is wood that has been infused with preservatives to protect the wood from rot and insects. This method has been used by most furniture manufacturers to create furniture that will remain strong and beautiful for many years.

What is the pressure treatment in wood?

Pressure treatment is placing wood in a depressurized holding tank where the air is removed. After air has been completely removed, this is replaced with a chemical preservative. This process is, by far, the best way to prevent harmful rot and insects but this will not avoid weathering and corrosion.

Using chemicals to pressure treat wood

There are several chemicals that can be used to pressure treat wood. The most common is chromated copper arsenic (CCA). The problem with this chemical preservative is that it is extremely toxic which is why its use caught the attention of the EPA who then began to investigate and regulate the practices of the companies that used CCA.

There are conflicting opinions as to the exact effect or possible danger of using CCA but one thing is for sure, existing wood that has been treated with CCA preservative is generally considered to be safe. This is true especially when the homeowner follows precautionary measures of using a penetrating oil finish every few years. In 2003, residential CCA production was stopped by the lumber industry but it is still the most effective chemical preservative and is still being used in many commercial and industrial projects.

Additional treatments to pressure treated wood

Older pressure-treated wood which contains CCA must be periodically treated with a sealant to lock in hazardous arsenic chemicals, newer pressure-treated wood also uses additional treatments. Newer wood also needs to be coated with a sealant to protect the wood from the effects of weathering and corrosion.

While pressure treatment protects the wood from insects and wood rot, the sealant creates a barrier to external damage like weathering and corrosion. The sealant also prevents the wood from drying too fast which leads to warping. Paint and varnish can also be applied to pressure treated but this must be allowed to dry for at least one to two months.

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Using fasteners, connectors and other hardware on pressure treated wood

Aside from considering treatments for pressure treated wood, you may have also heard about using fasteners and connectors. Fasteners could be any kind of hardware that fastens two pieces of wood together. This could be a nail, screw, bolt, or anchor that holds the different pieces of wood. The connector is a similar term used for any manufactured device that connects two pieces of wood as well.

Most often fasteners and connectors are used to complete the construction of a wood project.

There is no special hardware for pressure treated wood but to be safe, consider the size and weight of each piece of pressure treated wood that you will use for your project and consider your purpose.

For instance, fasteners and connectors for two pressure treated wood to be manufactured into cabinets are generally sturdier and more durable compared to two pieces of wood to be used for decorative items.

Where to use pressure treated wood

If you are wondering if you can use pressure treated wood on your next project, the answer is yes. In fact, wood for any outdoor project should be pressure-treated but wood for indoor projects should be left as is.
Consider that the sawdust from pressure-treated wood is an irritant when inhaled or when these come in contact with the eyes, nose, and skin.

Some low-level leaching can also be a problem when pressure treated wood is used indoors. Make sure to select the ideal wood species to give you the best type of wood that is impervious to rot and insects. But if you intend to use pressure treated wood for an outdoor project then no doubt this will surely last for decades.


Pressure treated wood is durable, efficient and versatile material that is ideal for outdoor woodworking projects. This type of wood is resistant to pests and wood rot and when properly and periodically treated, this could remain strong and lovely for years and years to come.

  • December 29, 2018
  • DIY