Timber is one of the most versatile, reliable and sustainable building materials to use – ideal for different types of construction in indoor as well as outdoor settings. In addition, it offers an element of sustainability that is hard to come by with other types of building materials.
To find out more about the sustainability and cost saving benefits of using timber, read our article here (link here)
The next step is making sure that you choose the right preservative class timber for your project. What this means is that depending on the goals for your project, the timber you use will have to undergo a specific level of treatment in order to be suitable for your project. This is important for several reasons:
- Preservative treatment adds durability
Timber in its untreated form is not durable for most building and construction purposes. It is vulnerable to attack from various insect species, as well as other wood destroying agents like fungal decay. Untreated timber that is used, especially in outdoor settings, is exposed and susceptible to extreme decay due to weather and other environmental conditions.
Making use of timber that has been treated according to the correct preservative class adds a vital component of durability to your structure.
- Different wood structures require different preservative classes
The process of treating timber with wood preserving chemicals has been refined and perfected to ensure years upon years of stability and strength in wood structures. In South Africa we have five different class levels of treatment, each one engineered for the purpose of different timber applications. As an example, the treatment class of timber to be used for a wall in an indoor setting will be different from the treatment class of timber used for a jetty.
It is essential to understand the specific needs of your project in order to ensure longevity and sustainability in the performance of your timber. When you use timber that has been treated with the correct preservative class, you’ll have peace of mind knowing that the material will stay strong, retain its aesthetic appearance, and stand the test of time.
- Extends the service life of your timber
Essentially, choosing the right preservative treatment class extends the life of your timber significantly, because you will be using wood that has been treated to endure specific conditions and to withstand specific environments. You are left with an exceptional quality product to enjoy for years to come.
Here’s a breakdown of the five different class levels of timber treatment, as per the South African National Standards (SANS):
- H2 CCA Treatment – Internal (Low hazard): Applied to timber used in indoor applications. This includes flooring, panelling, beams, doors, cupboards, window frames and more. This treatment class is ideal for those indoor renovations and DIY furniture / decor projects.
- H3 CCA Treatment – Exterior Above Ground (Moderate hazard): This treatment class covers any project where your timber is used outdoors and above ground. Think about fencing bearers and slats, outdoor above ground decking and steps, garden furniture, gates and cladding.
- H4 CCA Treatment – Ground Contact (High hazard): It’s important to make the distinction between timber that is used above ground and in ground. Timber used in ground are more susceptible to rotting and termite attack. The H4 treatment class is used for this purpose specifically. This includes flower boxes, fencing, carports, decking, telephone and lighting poles, playground structures and more.
- H5 CCA Treatment – Freshwater and Heavy Wet Soils (High hazard): If your timber is going to be exposed to continual wetting, or planted in wet soil, this will be the treatment class to use. Therefore, H5 CCA treatment is vital for applications like freshwater jetties, drains, slipways, agricultural poles exposed to frequent irrigation, and foundation poles for permanent structures.
- H6 CCA Treatment – Marine (High hazard): Lastly, marine applications of timber require an exceptionally high level of protection against sea water, as well as borers, an insect that bores into wood. Marine jetties, slipways, retaining walls and walkways all fall under this treatment class.
The good news is that we are here to help you determine which preservative class timber you should be using for your project. With years of experience, our industry experts will guide you in your journey to choosing the perfect timber, and provide you with a quality product that will last a lifetime.
