admin | December 6, 2021
In countries such as Burkina Faso, as people have become wealthier, they have transitioned to using concrete instead of mud to construct houses. Concrete is seen as a more luxurious, modern material. But there are a variety of advantages to using mud, including keeping the house cooler. In addition to keeping out heat, mud is a more environmentally-friendly material than concrete. The manufacturing of cement, a key ingredient in concrete, accounts for around 5% of global CO2 emissions. Additionally, people with concrete homes may need to turn to other non-environmentally-friendly cooling practices, such as using air conditioning. Many people turn to concrete instead of mud out of concern that mud will collapse during extreme rainfalls. But the use of wide, metal canopy roofs, and reinforcing mud with small amounts of concrete, help to reduce the risk of building collapse during heavy rainfalls.
A group of architects in West Africa are pushing to use mud over concrete to build houses.
In countries such as Burkina Faso, as people have become wealthier, they have transitioned to using concrete instead of mud to construct houses. Concrete is seen as a more luxurious, modern material.
However, there are a variety of advantages to using mud, including keeping the house cooler than concrete. When mixed with motor oil and cow dung, mud creates a waterproof layer to protect the home from rain. Sanon Moussa, a retired librarian in his 50s who lives in the village of Koumi, says, “The mud will keep us cool. The motor oil, clay, and cow dung will keep us dry.”
Many people turn to concrete instead of mud out of concern that mud will collapse during extreme rainfalls. This has happened a number of times in Burkina Faso.
A big concern with concrete, however, is its inability to regulate heat as well as mud. Because cinder blocks have hollow centres, they allow heat to easily pass through and become trapped inside the structure, while mud provides a solid barrier to prevent heat from entering. For example, on the day National Geographic journalists and photographers visited a village in Burkina Faso, the mud home they visited was 14 degrees Celsius cooler than the outside temperature, in the mid-20’s compared to 40 degrees.
In addition to keeping out heat, mud is a more environmentally-friendly material than concrete. The manufacturing of cement, a key ingredient in concrete, accounts for around five percent of global CO2 emissions, making it a less sustainable alternative to mud. Also, people with concrete homes may need to turn to other non-environmentally-friendly cooling practices, such as using air conditioning. With Africa experiencing the extreme effects of climate change, natural solutions like mud are beneficial.
Another benefit of mud is that it maintains traditional construction practices. Architects have been finding new ways to stabilize mud structures to avoid collapse. Francis Kéré is a Burkina Faso-born architect who promotes eco-sensitive architecture. Mr. Kéré acknowledges that using mud as a construction material can create risk when there is heavy rainfall, which is why he and other mud advocates are finding new ways to make the material safer for building homes.
One solution Mr. Kéré and his team have developed is adding metal canopy roofs. These roofs are broader than current designs and extend further out from the walls, creating a steadier and more solid roof.
Mr. Kéré also suggests adding a very small amount of cement to the mud while mixing the earth bricks, which helps make them stronger and more solid, and thus less likely to fall apart during heavy rain. He emphasizes that using proper care when making mud bricks and not cutting corners improves the safety of mud buildings and decreases the chance of collapse.
In clinics across Burkina Faso, doctors report a roughly fivefold increase in heat-related admissions and deaths over the past decade. Some doctors suspect that a disproportionate number of these patients are men and women who’ve rebuilt in concrete but lack the means to artificially cool their new houses.
“The reality is that cement construction is simply sexy,” says Mr. Kéré. “But it’s bad sex because you don’t have the materials you need. It is not producing comfort.”
Mr. Kéré suggests that part of people’s hesitation about using mud and their desire to move to concrete stems from the spread of “half-truths about mud’s dangers.” He believes that people simply need more examples of what “well-built mud architecture can offer.”
This story is adapted from an article written by Peter Schwartzstein for National Geographic, called “Why these West African architects are choosing mud over concrete” available at https://www.nationalgeographic.co.uk/history-and-civilisation/2021/11/why-these-west-african-architects-are-choosing-mud-over-concrete
Photo: A worker carries mud at the site of a future clinic that will be Burkina Faso’s largest building covered with mud-brick . The technique uses neither wood nor metal. The Morija clinic, designed by architect Clara Sawadogo, is in Kaya, 60 miles north of Ouagadougou, the capital.
Crédit: Moises Saman, National Geographic.