Pro's and Con's of Creosote and CCA

Pro's and Con's of Creosote and CCA

SAWPA draws no distinction between the wood preserving properties of Creosote and CCA. Both are able to effectively protect wood from attack by fungi and insects. They are however very different in their form.

Creosote is a black oily substance whilst CCA is a water-borne treatment. A comparison of the important properties of each preservative is given below:

PROPERTY   CREOSOTE CCA
Efficacy Fungi
Termites
Wood-borers
Marine borers
Good
Good
Good
Good
Good
Good
Good
Good
Permanence
(Preservative losses)
Bleeding
Leaching
Evaporation
Fair
Slight
Slight
None
None
None
Penetration  

Good Good
Effect on wood properties Strength
Dimensions
Flammability
Corrosiveness
Paintability
Gluability
Colour
Odour
Cleanliness
None
None
Slight
None
Poor
Poor
Dark
Strong
Oily
Slight
Slight
None 1
Slight 2
Good 3
Good 3
Light Green
None
Good
Toxicity  

High High 4
Water Repellency  

Good None 5

1. Timber treated with CCA may be damaged by intensive veldfires as a result of its susceptibility to ‘afterglow.'
2. CCA-treated timber should be left for at least seven days after treatment before fixing metal fasteners or fittings.
3. Except where the preservative formulation contains a water-repellent system such as wax or waxy oil which may have a detrimental effect on the paintability and gluability of the treated timber.
4. Once it has completely reacted with the wood constituents, CCA-treated timber is completely safe to use and handle.
5. Water repellency may be introduced with the inclusion of a wax/oil additive.