Time to build with timber

Sawn timber, a locally grown, sustainable resource, provides the raw material for the construction of timber frame buildings using cutting edge cross-laminated-timber technology to lock in carbon and minimise environmental impacts.

How engineered wood can decarbonise the South African built environment …
by Roy Southey, Executive Director, Sawmilling South Africa

Our planet is faced with both an environmental crisis and housing crisis. There is, however, a sector that is overlooked as a viable, renewable and long-term solution to climate change and urbanisation.

Having recently attended the annual Wood Conference in Cape Town, I was inspired to hear and see how timber is being used successfully in the built environment, not just in the northern hemisphere but also on home soil. From modern homes in an off-the-grid community in Mogale City to a learning centre in the Drakensberg, from a new home in Knysna or a rooftop extension to a Johannesburg home to the Green Point Education dome in Cape Town.

At the mention of wood, your mind’s eye might only be able to conjure an image of a log cabin or “wendy house”, or perhaps a roof truss or timber flooring. It’s unlikely that you imagined a multi-storey building made from cross laminated timber (CLT), a type of engineered wood for mass timber construction.

You’re forgiven, considering that less than 1% of new South African houses use timber as the primary construction material. By comparison, some 90% of new houses in New Zealand are made of timber.

As a sector trying to promote the adoption of mass timber, we are faced with a long-held belief that brick-and-mortar is the only way to build homes, schools and clinics. There are many misconceptions, not least of which being strength, durability, fire safety, and cost. Many people view wood as rudimentary or weak.

Mass timber uses technological advancements to engineer wood to have a stronger strength-to-weight ratio. In the case of CLT, thin layers of timber are laid crossways before being bonded and compressed together.

It’s been said that wood isn’t manufactured, it grows. From a South African perspective, the wood is sourced from sustainably managed tree plantations.

Pine timber grown by AC Whitcher in the Western Cape … it’s time has come.

The forest products sector is the only one to have the trifecta of green solutions when it comes to the carbon sequestration by trees in managed forests, carbon storage in its products and the substitution of carbon-intensive materials with wood-based products.

The construction sector accounts for 35-40% of global energy related CO2 emissions, with a large proportion (embodied emissions) attributable to the extraction, processing and energy-intensive manufacturing of building products. The other main source is operational emissions from heating, cooling and power generation.

Timber boasts a significantly lower carbon footprint compared to traditional building materials like concrete and steel. Timber also maintains a carbon-negative status throughout its lifecycle, from initial production to disposal, and it sequesters more carbon than it emits during processing and installation.

Our colleagues at the Stellenbosch University, Prof Brand Wessels and Dr Philip Crafford have published various pieces of research, highlighting the advantages of increased timber use in South Africa. Basic modelling analyses show that if the market share of wood-based buildings increases to 20% of new constructions, the embodied energy and global warming potential of the residential building sector could decrease by 4.9%.

As our population and economic migration increases, there is an urgent need to change how we build high density and single family housing, quickly, cost-effectively and sustainably.

Human friendly, planet friendly, timber is the ideal building material of the past and the future.

There is a climate, economic and even social case for timber, and a significant opportunity for innovation, localisation and employment creation. Several industry players, architects, construction engineers and producers are focused on making engineered wood more accessible to the local market. With this comes the need for upskilling or reskilling, business growth and employment opportunities.

Wood lends itself well to modern, modular and off-site methods of construction, with improved efficiency and performance. Single and multi-storey buildings are prefabricated off-site, allowing for quicker on-site assembly, less journeys to and from site (and the associated carbon emissions), and minimised disruption, dust and noise.

Biased towards tried-and-tested steel and concrete, the public and private sector is reluctant to drive the use of timber in the built environment through procurement policies.

Through initiatives such as the Forestry Master Plan, partnerships with the Department of Trade, Industry and Competition and forward-thinking academia, we want to shift the needle in favour of using locally grown and processed timber.

Both the University of Pretoria and Stellenbosch University have a strong wood science focus, and helping to educate a new generation of architects and construction engineers.

Dr Schalk Grobbelaar, senior lecturer and chairperson of the York Timbers Chair in Wood Structural Engineering in University of Pretoria’s Department of Engineering & Technology Management, is a champion for our cause. He believes that a design-led approach is crucial to successful risk management where timber solutions are used, while also exposing people to possibilities that timber brings.

Dr Grobbelaar’s team has been focusing on traditional timber frame construction combined with modern CNC machined plywood/OSB modular construction.

Prof Wessels and Dr Crafford have also developed The Wood App, a platform that offers architects, builders and designers with access to a host of CPD accredited courses on local wood standards, materials and best practice.

The sawmilling sector, while small in comparison to other industrial sectors, supplies sawn timber and other products for various applications, from structural timber to moulded and machined products for decking, flooring and ceilings. Many of these sawmills operate in rural or peri-urban areas, providing much-needed employment to thousands.

The uptake of timber represents a massive opportunity for our country and our planet. It’s time to trust in timber.

Illegally treated timber seized

Arch Wood Protection South Africa has praised the National Regulator for Compulsory Specification (NRCS) for seizing R1 million worth of illegally treated timber, describing it as a big win for the treated timber industry.

“We are pleased to see the regulator taking such a firm stand on illegally treated timber that is currently flooding the market as a cheaper alternative to quality pressure treated timber. This is a big step forward in protecting the industry and all its stakeholders against substandard products,” said JJ du Plessis, senior business manager at Arch Wood Protection South Africa.

Du Plessis said that the industry has always strived to introduce robust standards that protect the end-user, but over the last few years they have seen increasing levels of activity by groups that choose to operate outside the standards and regulations that govern the industry. This, he said, has caused substantial reputational damage to the timber industry.

“We want to also commend the South African Wood Preservers Association (SAWPA) and the NRCS for ensuring ongoing collaboration to ensure that treated timber remains part of a sustainable way forward in South Africa. This multi-pronged collaboration amongst important stakeholders will ensure that high quality remains the hallmark of our industry,” said du Plessis.

All wood preservatives used in South Africa must be registered with the Department of Agriculture and comply with the SA National Standards. Use of timber in building construction is also regulated by the Building Regulations, which ensures that it is treated against termite and wood borer attack, as well as fungal decay.

There is also a National Standard governing wood preservative operations to ensure the safe handling of preservative chemicals to mitigate health and safety and environmental risks.

Three types of preservatives are used in SA; water borne preservatives (e.g. CCA), oil-borne preservatives (e.g. creosote) and light organic solvent borne preservatives.

Compliance with the regulations and national standards ensures that timber sold to consumers is fit for purpose and will last for the duration of its intended lifetime. Use of untreated timber, or poorly treated timber impacts negatively on consumers, and may also pose health, safety and environmental risks.