Commercially grown species of timber such as Pinus and Eucalyptus have low natural durability, rendering it susceptible to insect and fungal attacks. Preservation is therefore imperative.  

The South African Wood Preservers Association (SAWPA) advises on the types of wood preservation namely primary (industrial) and secondary (DIY). 

Different types of wood preservation 

Primary preservation pressurises the wood with an industrial chemical wood preservative.

Primary: Wood is pressurised with an industrial chemical wood preservative, e.g. Chromated Copper Arsenate (CCA) or creosote. This process increases the long-term durability and resistance to fungi and insect attacks. 

Secondary: Used for supplemental (preventative) and/or remedial purposes and applied by hand to previously untreated timber, or exposed ends of machined pressure-treated timber. 

Protective wood sealers or varnishes are not regarded as secondary preservatives unless they contain active ingredients (biocide). Finishes without active ingredients merely protect against weathering, i.e. moisture and ultraviolet (UV) rays.  

Types of preservatives 

Primary preservation is categorised into “H” classes for different applications. 

CCA safety tips  

• Wear a dust mask, gloves and safety glasses when machining. 

• Do not use when making toys, furniture or food utensils, nor to store food or water. 

• Should not be used in beehives, nor for animal litter where it may become a component of animal feed.

• Do not burn treated wood off-cuts, nor use it for firewood or food preparation. 

For more information, contact SAWPA: 

Tel: +27 11 974 1061 

Email: admin@sawpa.co.za 

Website: https://sawpa.co.za/