Why Treated Pine Makes a Great Choice for Your Pergola

There are some very good reasons to choose treated pine rather than the more costly hardwood varieties when building a pergola. This less expensive option is now becoming a very popular choice and is well worth considering.

Learn about treated pine and how you can save money and at the same time make use of an environmentally friendly product when building your pergola or deck.

Treated Pine Basics

There are several types of treated pine and it helps to know exactly what you are buying when choosing your timber. There are different ways of treating the pine:

Copper Chrome Arsenic (CCA)

The familiar green colour of the timber will alert you to the fact that it has been treated with arsenic to boost its durability and resistance. This was the earliest form of treatment used to protect the timber against rot and insect infestations and it is still used in Australia today.

However, timber treated with CCA is no longer recommended for use in situations where people come into close contact with it on a regular basis. The health effects of the arsenic components and the effects of the chemical on the environment are now known to be harmful. Fortunately safer alternatives are now available for use in home building projects.

Alkaline Copper Quaternary (ACQ)

This water based copper treatment is the most widely used today and is considered to be a far superior option. The compound is known to be harmless and also allows the timber to retain its natural attractive colour. It is equally as effective as CCA in providing protection against fungi and termite damage.

Light Organic Solvent Preservative (LOSP)

This lower impact treatment makes use of a solvent material--such as white spirit--that provides a protective envelope around the timber. Pine that is treated in this way however, is not suited in situations where it comes into direct contact with the ground.

Treated Wood Classifications

Once treated with any of described methods the pine is also classified according to its durability and the protection level that it provides against hazards.

There are six levels that indicate the type of usage for which the timber is best suited.

  • For above ground outdoor purposes, such as pergola posts and frames, timber should be H3 level

  • For outdoor in-ground situations where the pergola posts make contact with the ground - H4 level is the requirement.

Reasons to Build with Treated Pine


Naturally a strong reason to opt for treated pine is its comparatively low cost. It is far less expensive than its hard wood rivals including jarrah and mahogany. It is also equally comparable in its durability and will perform just as well over the years.


Treated pine is virtually maintenance free. The treatment assures it will not suffer from fungal infection or damage from insect invasion. Applying an initial coating of polyurethane will harden the surface and maintain an attractive sheen for years.


As it becomes exposed to the harsh sunlight of the Australian climate over the years, you can be assured that it will endure.

Ease of Handling

Being a lightweight timber, treated pine makes it easy when lifting overhead beams, It allows the average home handyperson to manage and handle it without any difficulty.

Environmental Factors

It is comforting to know that pine is a renewable resource. It is fast growing softwood and can often be harvested from plantations where it is specifically grown and cultivated for cutting.

Ultimately, by choosing treated pine for your pergola you not only making a budget friendly decision, you are opting to use a sustainable resource and will enjoy long-lasting structure.