Timber iQ February - March 2020 // Issue: 48 | Page 17

ASSOCIATIONS
Helpful information on
dried timber
Dineo Phoshoko
Timber goes through many different steps before it can be used in
construction. Drying timber is one of the important steps during the
processing of timber for construction.
T
imber iQ spoke to Abe Stears, managing director
at the South African Timber Auditing Services
(SATAS), who answered a few questions on
drying timber.
WHAT ARE THE IMPORTANT FACTORS TO
CONSIDER IN TERMS OF KILN DRYING?
Moisture needs to be below 15% in order to grade properly.
Timber shrinks during drying, causing movement influencing
the dimensions and also deformation.
Kiln drying also sterilises the timber getting rid of all
possible insects and wood destroying fungi. A controlled
environment ensures an even moisture content of the whole
kiln load.
WHAT ARE THE REGULATIONS AROUND
KILN DRYING FOR TIMBER USED IN
CONSTRUCTION?
Structural timber is regulated by the National Building
Regulations which refers to the relevant national standard.
www.timberiq.co.za
The Standard (SANS 1783 Part 2) stipulates the timber to be
of a moisture content of below 15%.
HOW CAN END USERS IDENTIFY AND
ENSURE THAT THE TIMBER THEY ARE
USING FOR CONSTRUCTION IS KILN
DRIED?
Timber is graded by a certified sawmill or grading facility,
and the standard prescribes certain information to be
stamped on each unit. If there is a stamp of a SANAS
accredited product certification body as SATAS, on the
timber it must comply with the standard requirements.
IS THERE ANYTHING YOU WOULD LIKE
TO ADD OR HIGHLIGHT?
It is not illegal to airdry structural timber. Timber does not
have to be kiln dried. As long as the timber complies with
the standard requirements, it is acceptable. This [timber that
is not kiln dried] is however a time-consuming practice with
poor results if not done correctly.
// FEBRUARY / MARCH 2020
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