Bamboo – why isn’t it our biggest building material?

Bamboo has a few downsides, but environmentally speaking, it could change the game for sustainability in buildings. Among its many positive attributes is that it has a negative carbon footprint, is stronger than non-sustainable concrete and bricks, and will last much longer when used in flooring, cabinetry, and other uses. It could also create jobs and produce one of the world’s most sustainable commodities for building, help with reforestation and soil erosion reduce our use of chemicals. What’s not to like.

Sustainable, versatile, strong, and quickly replenished, bamboo could be the building material that brings us closer to a net-zero carbon footprint. But why hasn’t a large-scale bamboo industry been considered for Australia?

University of Southern Queensland (UniSQ) research student and engineering officer Mari Miranda told The Fifth Estate that it was likely because of the lack of knowledge surrounding how to use bamboo as a construction material because of the difficulty of connecting bamboo’s hollow and thin-walled culms, or stems.

Australian builders expect more regular profiles in their building materials as this can contribute greater savings on construction time and labour,” Miranda said. “It’s not like you can use typical nails, rivets or bolts to join the poles; you need a specific joint or connecting system to support bamboo construction.”

Another reason is historical – there was not much bamboo around in Western countries at the time of the Industrial Revolution compared to steel, which was abundant.

This meant that the industrial process became highly controlled and homogenous in quality and specifications, so industrialised nations – such as Australia – ended up with quality standards that penalise safe materials that don’t comply with historical standards.

Other problems with bamboo include the need for treatment, as the starch in the plant can be a strong attractor for insects. That’s not the case with engineered bamboo. Products such as laminated bamboo lumber have become popular in Australia. However, a downside is that manufacturing these uses 30 per cent more energy than using the natural round form of the plant.

“Bamboo can fit into the construction outlook by using laminated bamboo, and every bamboo species can be used for lamination; this means it’s not species-specific,” added Ms Miranda.

Why bamboo is considered the best and most eco-friendly material

• It grows quickly; in fact, it’s one of the fastest-growing plants on the planet – some bamboo species have been reported to grow one metre in 24 hours
• It continues growing and spreading without needing to be replanted after harvest
• Harvest of hard timber-like bamboo can be carried out in five to nine years (compared to wood which is every 10 to 20 years), making it highly affordable
• The plant is also classified as perennial grass, meaning it can be sustainably grown on every continent except Europe and Antarctica and requires less water than timber
• It has an extremely low carbon footprint and stores four times more carbon than timber, and produces 35 per cent more oxygen than a timber forest
• Bamboo actually has a negative carbon footprint
• It doesn’t need pesticides or fertilisers
• Since it’s grass, it has a complex root system that prevents soil erosion
• It is currently widely used in reforestation programs to rehabilitate soil
• And despite appearances, bamboo has a high strength-to-weight ratio ranging on an average of 31.6 to 95.8 megapascals (MPa) in tensile strength, which is two to three times stronger than hardwood and almost comparable to steel reinforcement. The 1-millimeter outer layer can present a maximum of 340 MPa
• This also means it’s stronger than non-sustainable concrete and brick and will last much longer when used in flooring, cabinetry, and other purposes
• Production in countries such as India, Japan, and China have multiplied with the introduction of bamboo into manufacturing scaffolding
• This is especially true in Hong Kong, where bamboo has become the standard material for scaffolding due to the high demand for skyscrapers
• This scaffolding in Hong Kong earthquake resistant and will stay standing even when multiple canes break – it takes a fire to destroy this kind of scaffolding
• Central and South America uses the bahareque, which is a vernacular construction system that uses bamboo to make their buildings more durable and resistant to earthquakes and typhoons.

How does the industry look in Australia?

While there is no large-scale commercial growth of bamboo in Australia, there is a growing demand for the product.

There were few plantations in New South Wales and Queensland growing bamboo for structural use and one in the Northern Territory growing it for food.

“Not every bamboo species in its natural-round form is suitable for construction use. And mostly its uses are for temporary marquees, fences, light construction in home and garden.”

According to Miranda, bamboo imports to Australia only started in the 2000s by a small importer of flooring products. It was not until 2012 that bamboo flooring gained some traction in the Australian market – and after, it could demonstrate improved performance.

In 2015, the major timber flooring importers started accepting the product, but this was short-lived, with the industry collapsing again in 2016 because of the limitations of longer acclimatisation needs, installing issues its lower Janka rating at that time, Miranda said, referring to the industry standard for testing hardness and durability.

Bamboo is doing better in Europe in comparison

According to House of Bamboo, one of Australia’s largest suppliers of certified, engineered bamboo and rattan, European consumers have fallen in love with bamboo – it’s been a huge importer of the product, and now it’s growing the plant in Southern Portugal with growers recently expanding from 150 hectares in May 2021 to 2000 hectares now, contributing to eight of the United Nation’s Sustainable Development Goals.

BambooLogic, the organisation behind the idea, plans to expand to Spain, Italy and Greece. According to the European centre for the promotion of imports (CPI), import of bamboo in 2011 to the 28 European Union Countries was valued at 78 million Euros. This slowly decreased to 59 million in 2015 as Europe became more reliant on domestic growth of bamboo.

Australia’s opportunity

Much like Europe, Australia has the space and environment for a bamboo industry and the need to meet the growing demand for sustainable products in Australia.

House of Bamboo’s chief executive officer Jennifer Snyders believes that a local industry would not only reduce our carbon emissions, create jobs, and help us produce one of the world’s most sustainable commodities for building uses but also help with reforestation and soil erosion during the warmer months and reduce our use of harmful pesticides or herbicides.

Is bamboo the answer to our timber shortage?

“While the industry is not rapidly growing at the moment, there is a good chance of having a large-scale bamboo industry in the future if the focus is on improving laminated bamboo performance,” Miranda said.

“Australia is experiencing timber scarcity at the moment, and wood lamination technology is very much available and accessible. This means that the performance of laminated bamboo can be improved quicker and larger and can alleviate the shortage in timber.”

According to Ms Miranda’s research, several factors have an impact on why a country may choose to use bamboo as a building material, including the experiences of previous generations, the evaluation of its performance during disasters, the intuition of builders, and the practices used in its treatment and preservation.

“Planting bamboo alone can contribute to the Australian government’s agenda in reducing carbon emission by 2030 due to its fast growth, and then using the harvested culms for building products for locking the carbon longer may even contribute more to this reduction target.”

What now?

House of Bamboo’s Jennifer Snyders advocates for changes in attitudes and expectations.

“We often hear misinformation about how new bamboo products are manufactured – this is what we are driving to change and asking the building industry to listen and learn that not all products are created equal.

“High-quality timber alternatives are being made that aren’t full of chemicals – that meet and often exceed the sustainability merits of timber.

“We need to look at our practices, our projects and ask for more change and say can ‘I do it better?’ The more the industry grows, the more we can invest in Australian bamboo.”

This sentiment is echoed by Miranda, who wants to see bamboo as a mainstream construction material.

“Bamboo is the fastest growing and most versatile plant in the world, but Australia has yet to realise the enormous potential of bamboo culms which could help solve the nation’s housing and climate crises,” said Miranda.

“There are many bamboo structures in Colombia, Indonesia and China, so if they can build bamboo structures there, why can’t we build them here?”