Clay bricks: star performers in sustainability

Written by Emma Dawson • Online since 5.09.2017 • Filed under Advertorial • From Issue 6 - September 2017 - February 2018 page(s) 18-20
Clay bricks: star performers in sustainability

To improve the sustainability of building materials and understand their environmental and socio-economic impacts, the Clay Brick Association of Southern Africa has 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.

Buzz words abound in the construction sector – green, sustainable, eco-friendly, low carbon footprint, recyclable and reusable. We’ve heard them all, and for good reason: the growth and development of societies has a big impact on our natural environment and increasing a building’s efficiency is important for preserving our natural resources. Clay bricks have been around since Babylonian times. Dating back some 5 000 years, they are one of the oldest building materials and are still widely used  hanks to their durability, structural capacity and energy performance. Brick buildings shape South Africa’s architectural heritage – from schools, social infrastructure, hospitals, churches and stately homes to forts and lighthouses.

You will also see affordable brick homes, moulded from South African soil, that have protected and served South African families across several generations. The average clay brick structure lasts for more than 100 years, and there are numerous examples of buildings dating back 500 years. Clay brick structures have impressively high loadbearing capacity, and high-dimensional stability and compressive strength, which limits cracking and ensures structural integrity. They are incombustible, offering the maximum fire rating; and water resistant, making them impervious to all weather.

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 hold all the trumps. 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. Bricks can be crushed and recycled as aggregate for road construction, sub-base, or non-toxic landfill and site levelling. They can also be cleaned and reused for new building construction.

SA’s first industry-wide LCA

With these myriad benefits as a backdrop, it’s no wonder that the Clay Brick Association of Southern Africa (CBA) wants to drive home its environmental message. ‘A first step towards improving the sustainability of building materials is to understand the extent and source of their environmental and socio-economic impacts. It was with this intention that the CBA embarked on a four-year project to complete South Africa’s first industry-wide Life Cycle Assessment (LCA),’ explains CBA’s president, Musa Shangase. 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 the ISO 14040 and 14044 standards, and 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 1kg of fired brick.

These included:

• Calculating the resources consumed and emissions produced over the entire life cycle of clay brick.

• Assessing the impact of different methods of clay brick production against specific environmental factors such as human health, climate change and damage to ecosystems. The study used production data from 86 of the 102 clay brick production sites in South Africa, ensuring the results are a relevant and valid assessment of the industry.

• Quantifying the energy efficiency of six common walling materials across South Africa’s six climate zones and three types of building types (low-cost residential, residential and commercial). It compares heating and cooling costs during the 50-year use or occupation phase.

• Measuring a range of socio-economic factors such as health and job creation (social Life Cycle Assessment).

The big picture

‘During brick manufacturing, environmental impact mostly relates to mining, production and burning coal – the raw material used for combustion during firing. Because South Africa relies on coal-burning technology for the generation of electricity, switching to electric kiln technologies would not reduce environmental impact,’ explains Nico Mienie, CBA’s technical director.

By far the greatest share of climate and health impacts occur in the ‘use’ phase (50 years of building use and occupation). ‘Electricity used for heating, cooling and ventilating homes and offices in South Africa has a very high impact because electricity is predominantly generated by coal-fired power stations. The study measurements were based on residents living in reasonable thermal comfort (between 19 and 25˚C).

From a socio-economic point of view, the LCA assesses how the product affects workers, the community and consumers, which includes human rights, working conditions and health and safety.

‘It takes 26-man hours to produce 1 000 bricks, which results in four jobs created per million bricks produced. In South Africa, the brick industry provides employment, particularly in rural communities where it is most needed. What’s more, the industry actively engages in community development programmes, and brick makers significantly support SMMEs – from which they purchase 74% of their supplies,’ Mienie notes.

He adds: ‘A strength of our industry is its transparency and communication regarding environmental performance, and a positive impact regarding health and safety, and living conditions. Areas for improvement include equal opportunities for employment at higher education levels, and equal remuneration across gender and race.’

Committed to energy efficiency

‘The clay brick sector is committed to playing its part in meeting government’s targets to reduce carbon emissions. This makes clay brick an attractive option for both environmentally-conscious architects and cost-conscious property owners,’ Mienie insists.

Over the last four years, the Energy Efficient Clay Brick Project (EECB)’s energy-efficiency initiatives resulted in a 10 to 15% reduction in the industry’s greenhouse gas emissions,’ maintains Mienie. When asked why the LCA matters to the construction industry, Mienie notes: ‘Energy used during production is just a fraction of the total life cycle considerations of a building material. The clay brick industry LCA allows architects to accurately calculate the lifetime environmental impact of using clay brick in a building compared to other construction materials. Access to accurate data makes it easier to design green buildings that are naturally energy efficient.’

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 adds: ‘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.’

Know the facts

A regular South African Brick Industry Sustainab ility Report will be prepared to show how South Africa’s clay brick sector is performing against its collective sustainability strategy. It will demonstrate progress against targets set for fossil fuel use, waste and resource consumption. To disseminate the findings of the reports for construction decision makers, the most pertinent results from the main report are consolidated into a series of downloadable publications available for free from the CBA’s website.

‘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 energyefficient buildings and the importance of choosing suitable building materials,’ concludes Mienie.

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Issue 6 - September 2017 - February 2018

Issue 6 - September 2017 - February 2018

This article was featured on page 18-20 of SABI Magazine Issue 6 - September 2017 - February 2018 .

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