TREATMENT
Timber Treatment
Timber is an organic product and as such is subject to decay. In order to ensure its
ongoing safe use in structural and external applications, various treatment processes
have been developed. Depending on the nature of the exposure to insect and fungal
decay different hazard classes have been identified.
Hazard classes
According to the hazard class different amounts of preservative chemicals are used
by the treatment plant.

H2 - Interior above ground, eg. flooring, ceiling and mouldings

H3 - Exterior above ground, eg. decking, fence slats and rails, exterior
cladding

H4 - Exterior ground contact, eg. poles and posts
Treatment process
Geelhoutvlei Timbers offers two options, one in house, and the other outsourced.
Both are highly controlled pressure treatment processes controlled by the SABS and
in accordance with SANS 1288 and SANS 753.

TBTO clear solvent based preservative is used to treat ceiling and flooring to
H2.

CCA is a water borne inorganic formulation which is vacuum pressure
impregnated into the wood offering long term protection across all hazard
classes (H2 - H6) against wood borers, termites and wood decay.
Geelhoutvlei Timbers uses the world famous TANALISED ® C brand.
Special additive
In addition Geelhoutvlei Timbers uses the special additive TANALISED ®
WEATHERWOOD ®. This water repellent additive provides greater moisture stability
and reduces cracking in TANALISED ® timber.
Guarantee
Treatment on poles is guaranteed for 25 years. Treatement on sawnboard is
guaranteed for 50 years. This guarantee operates either via the SABS or Koppers
Arch, the makers of TANALISED ® C Brand
Further Information
For more detail on the treatment process and the chemicals used please refer
to www.koppersarch.co.za