Clay bricks: Promoting inclusive, sustainable practices

Online since 22.03.2018 • Filed under Infrastructure Development • From Issue 7 - March to August 2018 page(s) 24-26
Clay bricks: Promoting inclusive, sustainable practices

In 2017, the Clay Brick Association of Southern Africa produced the country’s first industry-wide Life Cycle Assessment. As part of a larger sustainability initiative, this assessment commits the clay brick sector to continuously improve water and energy savings and limit the use of coal as a firing fuel.

In 2017, the Clay Brick Association of Southern Africa (CBA) finalised a four-year project that produced South Africa’s first industry-wide Life Cycle Assessment (LCA).

‘A first step towards improving the sustainability of building materials is to understand the extent and source of their environmental and socio-economic impacts,’ explains CBA’s president, Musa Shangase. ‘To do this, the CBA commissioned two detailed scientific assessments to understand the environmental impact of clay brick production and use in South Africa. The independent studies were conducted by the University of Pretoria. The CBA also commissioned a social LCA, which was conducted by G1 Consulting & Associates and Equispectives Research & Consulting Services.’

An LCA quantifies the resources consumed and emissions produced over the product’s entire life cycle and then assesses the impact of this on specific environmental aspects such as human health, climate change, and damage to ecosystems. It allows property developers and building owners to make fact-based decisions in the context of building and operating sustainable, energy-efficient green buildings.

Conducted in accordance with ISO 14040 and 14044 standards with an external review to aim for the highest quality standards, the study evaluates all major environmental impacts including damages to human health, to ecosystem quality, to the contribution to climate change, and to the consumption of non-renewable resources for the six main brick manufacturing technologies with respect to the production of 1 kg of fired brick.

Committed to sustainability

The CBA is committed to sustainability in its sector and is delighted to have been co-funded by Switch Africa Green, funded by the European Union on the project ‘Promoting Inclusive Sustainable Practices in the South African Clay Brick Sector’. This grant promotes inclusive sustainability practices and will be used to explore sustainability in the sector.

Why the life cycle of a clay brick matters

Clay brick structures have impressively high load-bearing capacity, and high-dimensional stability and compressive strength, and are incombustible and water resistant. Also, because of the durability of clay brick constructions, life cycle cost analysis demonstrates long-term benefits – they require little to no maintenance, they’re easy to clean, and thermal expansion and contraction is minimal throughout the year thanks to their low thermal and moisture movement. For energy cost savings, clay bricks are excellent.

Their inherent thermal capacity significantly reduces the need for more expensive insulation materials between the brick leaves; and their ability to self-regulate means they keep internal spaces naturally cool in summer and warm in winter. Additionally, their thermal efficiency reduces the need for heating and air-conditioning, providing lifetime savings for property owners.

Another major benefit of clay bricks is that they can be salvaged and reused when the existing structure has outlived its usefulness.

So, what did the LCA studies find in terms of the highest impact and contribution to global climate change?

• Environmental impacts driven by dependence on fossil fuels

The most significant environmental impacts from the production and use of a brick are the contribution to global climate change, consumption of non-renewable resources, and emissions of substances that cause respiratory diseases. All three of these impacts are a consequence of the use of fossil fuels, primarily coal, either directly in the kilns during production or indirectly as electricity during use of the brick.

• A brick’s biggest impact is in its use

By far the greatest share of climate and health impacts occur in the use phase of the brick. The electricity used for heating and cooling houses in South Africa has a very high impact as it is predominantly produced from burning coal.

• The highest manufacturing impacts occur in brick firing

In terms of brick production, the highest environmental impacts occur during clay preparation and firing. The high impacts on ecosystem quality and resources are caused by the production of coal. During firing, the main impacts come from the emissions of burning fossil fuels, either from coal mixed in with the clay mixture as internal fuel, or from coal, natural gas or fuel oil used to fire the kiln.

• Kiln technology affects the brick’s impact on climate ecosystem quality, human health and resources

Of the six different kiln types used in South Africa, no one technology consistently performs better across all the different environmental impacts assessed, but continuous firing technologies perform the best. There are therefore minor improvements to be made to production processes by moving towards continuous firing technologies and using higher quality, cleaner-burning fuels. However, the savings that can be achieved in this phase are minimal compared to the savings that can be made during the use phase.

The importance of design and education

The greatest potential for the clay brick sector to reduce its environmental impact is by educating the building sector about the need for the design of energy-efficient building and the importance of choosing suitable building materials.

The Thermal Performance Study carried out in conjunction with the LCA found residential buildings constructed with clay brick walls to have the lowest heating and cooling requirements of all commonly employed walling systems in South Africa. In the temperate climate zones, potential energy savings of 30% were found for residential buildings built of solid brick walls, while savings of 70% were found for insulated cavity brick walls. In terms of climate change impact, this is equivalent to taking between three and seven passenger cars off the road for a month for every year the building is in use. Even higher savings are evident in the hotter regions and in non-residential buildings where electricity use for air conditioning is much higher.

Predominantly positive socio-economic impact

The brick industry provides employment, particularly in rural communities where it is most needed. It is also actively engaged in community development programmes, as well as being a significant supporter of SMMEs. It takes 26 man-hours to produce 1 000 bricks, which results in four jobs created per million bricks produced. An industry strength is its transparency and communication about its environmental performance and a positive impact regarding health and safety and living conditions. Areas for improvement include providing equal opportunities for employment at higher education levels, and equal remuneration across gender and race.

Continually improving industry sustainability

CBA has led research in brick production and brick building design for 54 years,’ says Shangase. ‘This information aids architects and engineers to maximise thermal comfort and energy efficiency in residential and commercial buildings. With the assistance of the EECB, several local brick manufacturers have already reduced their energy consumption since the LCA’s original data collection period.’

He concludes: ‘The LCA is part of a larger sustainability initiative that commits the clay brick sector to continuous improvement in terms of water and energy saving, as well as limiting the use of coal as a firing fuel. It offers guidance to our members who want locally-relevant statistics on which technologies offer reduced fuel use, improved air quality and low environmental impact.’ For more information, visit www.claybrick.org

Issue 7 - March to August 2018

Issue 7 - March to August 2018

This article was featured on page 24-26 of SABI Magazine Issue 7 - March to August 2018 .

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