What is H2 Treated Pine and What is It Used For?

H2 is the minimum level of treatment required to protect timber from attack by insects, including termites.

H2 treated pine is very easy to work with, making it great for DIY projects and for specific residential and light commercial construction applications.

This article looks at what H2 pine is and why it’s so popular.

What is H2 pine?

H codes represent different levels of timber preservative treatments. The different levels provide a different level of protection against biological decay.

The codes range from H1 to H6 with each code representing a different required minimum treatment, as displayed in the table below.

Timber Hazard level table | Building & Landscaping Materials
This table showing timber hazard level and treatment types has been reproduced with permission of the NSW Environment Protection Authority.

According to QTimber, H2 timber is the “minimum level of preservative treatment required to protect the timber from attack by insects, including termites. H2 preservative treatments are suitable in above-ground, well-ventilated situations protected from weather and wetting.”

H2 treated pine is therefore suited to above-ground well-ventilated areas protected from weather and wetting. This includes applications such as framing and flooring.

This type of timber is not suited for outdoor use and must not come into contact with soil. This is because H2 treated pine has been protected against termite attack but it has not been protected against decay fungi/rot.

The table here displays where the H2 Hazard Class sits in the Hazard Class Selection Guide.

What is H2 timber used for?

Treated pine 4 | Building & Landscaping Materials

H2 treated pine is suitable for a range of residential domestic applications such as wall frames, flooring, joinery and other applications where the timber will not be exposed to moisture.

It can also be used in light commercial applications provided the timber is not exposed to the weather.

This guide from the Department of Agriculture, Fisheries and Forestry says typical uses include “Framing, flooring, and similar, used in dry situations”.

H2 pine should also be used in areas that are well-ventilated to prevent the development of fungi (which it is not protected against).

H2 treated pine is suitable for above ground use only and should never be used in areas that are expected to come into contact with water or soil. This includes areas such as decks, garden beds or below ground retaining walls.

How long will H2 pine last outside?

H2 treated pine is not a suitable solution for outdoor use.

For projects that will be exposed to the elements, such as decking and landscaping, H3 or H4 treated are better options.

You could also consider hardwood timber such as Merbau or Spotted Gum.

What is the difference between H2 and H3 treated pine?

The main difference is that H3 is suitable for outdoor use.

The H3 class of treated pine has a higher hazard rating than H2, and as such is used in conditions where the timber may be exposed to the weather or is subject to wetting from time to time.

Typical uses for H3 timber include “Weatherboard, fascia, pergolas (above ground), window joinery, framing and decking” (Source).

Both types of timber protect against borers and termites. They both contain a type of treatment that acts as an insecticide, preventing the damage that termites can do to timber structures.

It’s important to note that both H2 and H3 should only be used above ground as neither variety is suitable for exposure to moisture at ground level or being in contact with soil.

What’s the difference between H1 and H2 treated pine?

The key difference between the two is that H2 contains synthetic pyrethroid and imidacloprid which protects against termites.

H1 timber is treated only with Boroin and therefore only protects against borer.


According to QTimber, H1 Timber is “suitable in above-ground, well-ventilated situations protected from weather and wetting.”

What’s the difference between H2 and H4 treated pine?

H2-treated pine protects against insects including termites. It is suitable for above-ground, interior use only.

H4 timber, on the other hand, is protected against insects including termites as well as severe decay that can occur from contact with soil. It is, therefore, suitable for outside, in-ground use such as fence posts or decking foundations.


What is H2F treated pine?

You may have heard the term H2F treated pine, which is essentially the same thing as the H2 treatment level.

“For timber treated to H2, for use south of the Tropic of Capricorn only, the designated treatment brand is H2 (F). The designated brand of timber that may be used throughout Queensland is H2.” (Source)

H2F is also known as ‘Blue Pine’, which is what Bunnings call their construction pine.

These types of timber are treated slightly differently but both offer protection against insects and termites.


Can you burn H2 treated timber?

Do not burn H2 timber. Burning treated timber will produce toxic fumes. Also, do not use H2 timber as firewood or mulch. The chemicals it contains make it unsuitable for these purposes.

Can you use H2 treated pine outdoors?

H2 treated pine is not designed for use outdoors because it is not protected against decay. If you intend to build an outdoor structure such as a deck, consider H3 or H4 treated timber.

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Steve Kropp

Based in Melbourne, Steve's passion is vegetable gardening, and he’s been writing about it for almost 5 years. He also loves all things DIY and is always looking for a new project. When not working on his own garden projects or blogging, Steve enjoys spending time with his family, cooking meals with produce harvested from his garden, and coaching his son’s footy team.


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