Timber iQ October - November 2019 // Issue:46 | Page 39

FEATURES
Timber can be used with other materials to create a unique structure.
opinion that it is unnecessary to exclude one building material
for another. “For example, timber, stone masonry and thatch
complement each other very well but timber can also be
utilised to enhance a modern look when mixed with aluminium
and glass,” says Bissett.
Sound insulation of a timber frame might be a concern,
however Bissett asserts that this should not be the case. “A
properly built timber home will inhibit the transfer of sound
from one room to another.”
TIMBER FRAME APPLICATIONS AND
SUITABLE TIMBER
Cronje explains that timber frames are ideally suited to the
scale of residential construction. “Industrial buildings,
however, typically have much larger spans, and while these
can be achieved using laminated beams, large spans are more
cost-effective when built out of steel.” Although large span
applications where aesthetics are important have been
achieved using timber – for example indoor swimming pools
and sports halls – this wouldn’t make sense for industrial
applications. This is mainly due to cost.
Bissett further adds that 80 % of the developed world
live in timber frame structures. “A large percentage of
commercial and industrial structures in other parts of the
world are timber structures or a mix of timber and other
materials. There are a few timber warehouses in built up
areas in South Africa although these are in the minority.”
Apart from homes, timber frames are also suitable for
warehousing and other large structures although not always
as cost-effective as steel. Bissett explains that timber has a
known rate of combustion making it safer for fire crews in
the event of a fire as it does not collapse as soon as it gets
hot. “Timber is also resistant to shock loads, and if designed
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correctly, can withstand the day-to-day bumps and scrapes
in a warehouse.”
SA Pine has been found to be the most suitable type of
timber for the construction of timber frames. The timber has
unique properties that make it suitable for timber frame
construction. “Pine is lightweight, has a very high strength-to-
weight ratio, is easy to work with, and if CCA (Copper-Chrome-
Arsenate) treated, has a lifespan exceeding most hardwoods,”
says Bissett. He adds that external cladding in South Africa,
Australia and New Zealand is usually CCA treated Pine. America
is different because Cedar is more suitable for the American
environment due to its resistance to termite and fungal attack.
CORRECT STANDARDS AND COMMON
MISTAKES
All building and construction has to be done according to the
correct standards. For timber frame structures in South Africa,
the correct standard is SANS 10082. “Every builder should
have a copy of SANS 10082, but very few are even aware of
its existence except those that belong to the ITC-SA,” Bissett
explains. He also distinguishes between the code of practice
of timber for the design of timber structures and code of
practice for timber structures in general. “Timber frame
homes should be designed in accordance with SANS 10163
– the code of practice for the design of timber structures and
built in accordance with SANS 10082 – the code of practice
for timber structures.”
Building timber frames according to standards removes the
margin of error which means quality timber frame structures.
According to Cronje, one of the most common mistakes made
during the construction of timber frames is insufficient
tie-downs. “One needs to keep in mind that timber frame
construction is a ‘lightweight’ form of construction, and as
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