The housing crisis in South Africa has a long and complex history, including costs and durability of construction materials. Many developing country governments are promoting bamboo as an affordable, sustainable and durable construction material. Is this an option for South Africa?
A brief history of the housing crisis in South Africa
After the fall of apartheid in 1994, the government implemented a number of programs aimed at addressing the dire housing shortages faced by many South Africans who were discriminated against by the implementation of the apartheid Group Areas Act. However, these programs were largely unsuccessful, and the housing crisis has persisted to this day.
One of the main causes of the housing crisis is the economic and spatial poverty that afflicts many South Africans. Many people live in informal settlements or shacks, with no access to basic services such as electricity, running water, and sanitation. This not only impacts quality of life, but also hinders the ability to escape poverty.
Bamboo has a number of benefits as a building material, including its strength but also its lightness, durability, and ability to grow quickly. As a fast growing grass with multiple uses, it is an attractive option for diversifying a portfolio.
Exploring the Potential of Bamboo as a Sustainable Commodity
Historically, endemic bamboo has been used by some indigenous South African peoples, and several bamboo species were brought into the country by indentured Indian labourers in the mid 1600’s for usage in construction, tool crafting, religious uses and food in the form of picked atjar among other things.
Bamboo has been used as a building material in Asia, Latin America and other parts of the world for many years. In Ecuador and Peru, bamboo housing initiatives have had a net positive impact.
South Africa has the right conditions for bamboo to be used as a cash crop on any scale, while treatment of selected construction grade material can create a new value chain close to where other resources are limited.
There is an entrenched narrative in South Africa that bamboo is a poor man’s material and that nobody wants to use it.
In our research and through our work, we have found that there is an increasing acceptance of bamboo for structures and other applications. The “Way” in which bamboo is currently used is ad hoc or cosmetic. There is scope for technological improvement through accessible educational material and skills development.
The private sector is embracing bamboo as an alternative resource or remedial tool, as in the case of phytoremediation or erosion control. Once the plant is established, annual harvesting is possible while the original function is not compromised.
Another example is Beema bamboo which can be used for bio-fuels or construction material or both. Other species are edible as well as being suitable for construction.
As fuel and energy prices continue to escalate making logistics more expensive, the pressure is on to be more efficient. One way of doing so is to grow and process construction material close to where building occurs without the need for heavy industrial equipment (eg mills for timber).
The versatility of bamboo makes it a flexible commodity which one can pivot based on demand.
Grading and Structural Usage of Bamboo: New Standards and Possibilities
Since 2021, the International Standards Organisation (ISO) – the same system that our SANS and SABS standards are based on– published two technical documents regarding the grading and structural usage of bamboo.
In summary, the bottom 7m of certain bamboo species is suitable for construction, given that the bamboo poles (called “culms”) are graded, treated and cured using the correct methods.
The ISO Document gives a Standard design for load bearing wall panels, which can be pre-assembled if needed. However, they also make provision for three alternative design methodologies:
- Partial safety factor design (PSFD) or load and resistance factor design (LRFD)
- Experience from Previous Generations
- Design by testing
There are other grading and design criteria in the documents, which are available on the ISO website.
Now that bamboo construction has entered the main-stream, there is renewed opportunity for designers and engineers to start exploring this material.
Bamboo, Human Settlements & Environment
Bamboo can be used for creating edges (kraals), wind breaks, erosion control, grey and black water management systems (sanitation).
Bamboo also sequesters a relatively large amount of carbon dioxide There are several reasons why this is the case, but some of the more interesting points are that the:
“root-shoot ratio of bamboo is generally higher than it is for wood. As a result of its extensive root system, bamboo stores more C02 under ground as in the surrounding soil. Unlike trees, which are usually clear cut, the regular and selective harvesting of bamboo culms doesn’t kill the plant or damage the ecosystem and below-ground carbon is not emitted as the bamboo forest continues to live on after harvest”.
Researchers at INBAR also calculate and conclude that the Carbon footprint over life cycle (C02 e / m3) for bamboo and bamboo products is in the negative, meaning more C02 is sequestered than emitted during the life cycle of certain products like flattened bamboo and plybamboo.
Bamboo uses around 40% less water than what a eucalyptus or wattle plantation would use, based on this 2022 Water Research Commission Report.
Ad hoc usage of bamboo in KZN.