Timber iQ October - November 2019 // Issue:46 | Page 21

ASSOCIATIONS
Myths about timber construction:
Setting the record straight
By Institute of Timber-SA
While timber construction has a relatively small footprint in South
Africa, with its host of environmental and performance benefits,
the building material is enjoying increasing popularity and interest
among the general public and trade alike.
PLANTATIONS, NOT NATURAL FORESTS
The notion that using trees to manufacture products is
environmentally irresponsible is related to perceptions
around deforestation of natural forests. “There is a distinct
difference between harvesting timber from sustainable
and well-managed plantations and the deforestation and
degradation of natural forests that should be protected. In
South Africa, we use timber grown in responsibly managed
plantations, which are like working factories with the sole
purpose of growing timber in a controlled environment for
the market. Managed by reputable bodies like the Forest
Stewardship Council (FSC), these plantations are operated
in line with the highest standards for ensuring
sustainability,” says Dr Wessels.
Recent studies show that tree planting and forest
restoration are the most cost-effective strategies with the
greatest potential of combatting global climate change.
Dr Phillip Crafford et al., recently published their
findings on the role that timber can play in reducing the
environmental footprint of the built environment. The
study, titled, The potential of South African timber products
to reduce the environmental impact of buildings, compares
several roof truss systems of varying materials using a
simplified Life Cycle Assessment (LCA) approach. The
study concludes that the timber roof truss systems
showed a lower environmental impact across the board
and “demonstrates the potential advantage of using local
timber products to reduce the environmental impact of
the truss and building industry in South Africa.” (Crafford
et al. 2017: 1)
www.timberiq.co.za
E
ven so, misconceptions about timber as a construction
material are still commonplace, limiting potential
users from enjoying the manifold benefits of this
unique, renewable building material.
According to Dr Brand Wessels, Chairperson of the
Department of Forest and Wood Science at the University
of Stellenbosch, the most common myths that circulate
among the general public and even the professional trade
about timber as a building material are: that using trees to
manufacture products is not environmentally responsible;
that wood structures are not as structurally safe and
durable as steel and/or brick and mortar structures; and
that wood structures are an obvious fire hazard.
Timber as a construction material is gaining popularity and
interest among the general public and trade.
STRENGTH AND DURABILITY
Contrary to the misconception that timber structures are
not structurally safe and durable, timber has a higher
strength-to-weight ratio than either steel or brick and
mortar. “This misconception may be linked to perceptions
around low-cost, poorly built informal housing of wood,”
says Dr Wessels, adding, “To the contrary, in some
applications, such as for housing in earthquake-prone
areas, wood is preferred above other materials. There are
structures that are 1 200 years old in Japan (an earthquake-
prone country), which attest to the material’s durability and
strength. As with any other material, a well-designed and
built wood structure will last a lifetime; conversely, a
poorly designed and built structure – of any material – will
not endure.”
According to Amanda Obbes, General Manager of the
Institute for Timber Construction South Africa (ITC-SA),
timber frame construction is a standard construction
methodology under the National Building Regulations
(NBR), which provide the necessary building codes for the
manufacture and construction of safe, legal and durable
structures that are built to standard.
TIMBER UNDER FIRE CONDITIONS
According to the ITC-SA, structural timber for roofing is both
commonplace and performs well under fire conditions.
// OCTOBER / NOVEMBER 2019
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