Should we use CCA treated or Untreated timber for construction?

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Treated Timber

In South Africa, treated timber is a requirement when building structures such as timber frames or decks. There are various ways timber can be treated, however, the most effective and preferred method is CCA pressure treatment where the chemicals are deeply penetrated into the wood.

This is what we want, we need a permanent solution to keep our wood protected against wood destroying elements permanently. However, not all timber product need to be treated. This is what this blog is all about, we want you to understand the differences between treated timber and untreated timber and their uses in various applications.

The difference between CCA treated and untreated timber

Untreated timber after manufacturing

Untreated timber

Untreated timber is as close to natural wood as you can get.  No chemicals are added, and it has not undergone any pressure treatment process. Usually, when building with raw wood you would have to be very careful where and how you use the timber.

Risk Factors of untreated timber

Once untreated timber comes into contact with the ground, it starts the slow decaying process. The moisture not only soaks out of the ground but the moisture in the air. If you are in a certain area with high moisture levels (like Oceanside etc.) your untreated wood will decay faster than inland. The reason for this is that wood-decay fungi start digesting moist wood, which then causes the wood to rot at an alarming rate.

When wood is in contact with the ground you are also exposing it to various wood termites. The termites can then start eating the wood from below. While you can use untreated timber for various structures, you are risking the structural integrity.

When to use untreated timber

Untreated timber is ideal for indoor use, in more sheltered areas where there is no need for protection against harsh weather conditions, insect attacks and the area is completely dry.

Examples of indoor wood are like architraves, skirtings, ceilings, and floorboards.

Untreated timber might be cheaper, but, if you are aiming at building a structure that will last decades, this is not the ideal way to go. When you use untreated timber for various structures, you are risking the structural integrity of your building. This is because there are various factors that contribute to the process of decay of your timber.

Treated Timber after manufacturing

CCA treated timber

Copper chrome arsenate (CCA) treated timber is wood that has been treated with a preservative containing copper, chromium and arsenic. Copper and arsenic in the preservative protect the wood from insect and fungal attack. Chromium (chrome) ‘locks’ the copper and arsenic into the timber and reduces the risk of the chemicals leaching out. The CCA process gives the treated wood a green tint.

Factors of CCA treated timber

CCA treated timber offers resistance against all the various harsh weather conditions and insects that might damage the wood. The various chemicals in the CCA treatment process are all selected to serve the purpose of locking out moisture and keeping termites and other wood-eating insects away.

Various chemicals treat the wood and allow it to have a longer life expectancy in harsh weather conditions and make it resistant to insects. The life expectancy of pressure treated wood is usually a minimum of 40 years, but at Sabie Poles, we have a lifetime guarantee on all our CCA treated timber products.  Using treated wood is also less harsh on our timber resources which makes timber farming more sustainable.

When to use CCA treated timber

Scientists developed CCA Treated timber in 1933 and since then, construction wood industries around the world have widely used it because of its durability.

Construction wood industries in South Africa adopted CCA Treated timber in the 1970’s and have been using it in the private and commercial sectors for construction purposes. High-pressure treated timber has different classes and uses.


H2 CCA Class
  • Internal Applications: Structural Timber, Flooring, Paneling, and More.
H3 CCA Class
  • External Above Ground Applications: Flooring, Ceiling, Cladding, Decking, Architraves, Quarter-rounds, Laths and Droppers.
H4 CCA Class
  • In Ground Contact Applications: Building and Fencing Poles and Playground Structures.
H5 CCA Class
  • Wet Soils and Fresh Water Applications: Retaining Walls, Jetties, Agricultural Net Poles, and Walkways.
  • SABS inspects each individual order.
H6 CCA Class
  • For Applications in Sea Water: Jetties, Walkways, and Retaining Walls.
  • SABS inspects each individual order

S5 construction grade timber

As a leading company in the timber industry, we recommend using S5 construction grade timber for construction. The South African Bureau of Standards (SABS) has certified our structural timber materials for use in big and small construction projects under the S5 Construction grade timber.

This also means that the timber meets the necessary standards of High quality and strength. People approve timber planks / Makappas for uses such as roof trusses, roof support, and building framework for windows and doors.  We also use S5 construction timber to make mouldings like decking, flooring and cladding.

The benefits of S5 construction timber

5 Benefits of using S5 construction timber

  • Timber components withstand movement

Unlike a brick or concrete house, a timber house can accept differential settlement of several centimetres without visible results and without damage.

  • Timber withstands impact

It can absorb impact and usually only suffers local indentation itself. The object causing the impact also receives minimal damage

  • Timber is easily worked

Both professionals and laymen can easily use simple tools. Highly industrialized methods can work it easily.

  • Timber has high thermal properties

These artificial materials use the best natural material in conjunction with their excellent thermal insulation.

  • Timber is pleasant in hot and cold weather

Wood retains its strength well at high temperatures and has relatively high specific heat and low thermal conductivity. Therefore, timber feels neither excessively hot nor cold at extremes of temperature.   

When building a construction, it would be wise to think long-term. Therefore, cheaper may not always be the best option. At Sabie Poles we strive to provide the best high-quality products to serve your building needs at a reasonable price.

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