compressed block

Senegal, located at the westernmost tip of Africa and bordering the Atlantic Ocean, holds a strategically important geographical position and is known as the “Gateway to Africa.” Senegal boasts convenient maritime transport, with a 500-kilometer coastline and three main ports: Dakar, Kaulaq, and Ziginsauer. Dakar, in particular, holds a central position in West African maritime logistics, facilitating the import of raw materials for compressed block and machinery, such as a soil brick making machine.

Senegal’s terrain is predominantly plains, with relatively flat and gentle slopes, except for hilly areas in the southeast. The national average elevation is below 100 meters. Senegal has a tropical savanna climate, with more rainfall in the south and less in the north. From July to October each year, influenced by the southwest monsoon, the region experiences its rainy season. This favorable geographical location and natural environment have created conditions for diverse soil types. So, what is the composition of Senegal’s soil, and is it suitable for producing soil brick? Let’s explore the distribution and composition of Senegal’s soils.

Compressed block technology was introduced to Senegal as early as 1987. At that time, in the small town of Urro Sogi, northeast of the capital Dakar, the local community collaborated with the association of the French town of Valence to build a community center, hospital, school, and guesthouse using soil bricks for the first time. This was Senegal’s first successful case of using compressed bricks in building construction. Following the success of this project, local businesses and builders saw a business opportunity and began exploring and researching hand making bricks in 2010. They eventually developed a unique local production process, mixing local soil with cement and then manually pressing the mixture to produce the bricks.

In 2016, Worofila, a firm specializing in green building, used compressed block to construct villas, hospitals, schools, and other buildings, including the waiting area for the Dakar train station. The unique aesthetics and functionality of facing bricks gained widespread popularity locally and were recognized by the Senegalese government. Subsequently, they constructed over 2,000 housing buildings in Senegal, including schools, communities, housing, medical centers, and libraries.

01. First, we will explore the soils of western Senegal (Thiès region)

Our latest 2026 study of laterite quarries in the Thiès region of western Senegal (Lam-Lam, Mont Rolland, and Pout) revealed that the soil in this area is dominated by minerals such as quartz, kaolinite, hematite, and goethite. Quartz provides the framework for compressed block, kaolinite enhances their plasticity, and hematite and goethite, as iron oxides, act as natural hardeners. Based on chemical composition, the soil in this region is classified as ferruginous laterite, with high iron oxide content and low organic matter content, which is beneficial for improving the strength and stability of the old clay bricks.

Therefore, based on our research and analysis, the soil in western Senegal (Thiès region) is very suitable for producing compressed block.

According to research and analysis by the laboratory of the University of Thies, the soil in this region has an organic matter content of less than 3%, exceeding the 5% standard for high-quality soil. Furthermore, the SiO₂ ratio is less than 1.33, and the Al₂O₃/Fe₂O₃ ratio is less than 1. Based on this data, the red soil of the Thiès region in western Senegal is perfectly suited for producing soil brick and for road construction. Detailed data also exists regarding the soil-cement ratio: adding 8% cement to the soil raw materials for producing clay bricks results in a brick strength of 4 MPa, while adding 10% cement achieves a strength of 5 MPa. This strength exceeds the requirements of the Organization for African Standardization (ORAN) for soil bricks price strength. The local soil is ideal for builders to use an automatic brick making machine to produce coco soil bricks.

So, how did the high-quality soils of western Senegal (Thiès region) come about?

Firstly, there is the weathering of the rocks. The rocks in this region are mostly virgin parent rocks containing minerals such as feldspar and mica. Over millions of years, these minerals have gradually transformed into lateritic minerals. Secondly, western Senegal (Thiès region) is located in the tropics, with a hot climate and distinct wet and dry seasons, which accelerates the weathering process. During the rainy season, rainwater dissolves soluble elements such as silicon and calcium in the rocks, while during the dry season, insoluble elements such as iron and aluminum accumulate to form ferruginous lateritic soils. During this lateritic process, the feldspar and mica in the rocks are transformed into kaolinite clay.

Currently, western Senegal (Thiès region) is one of the fastest-growing areas for compressed block production. The region boasts high-quality soil and research data from the Iba Der Thiam University laboratory, providing excellent raw materials and scientific data for compressed bricks production, making it one of the best locations for investment and production. If you are interested in a clay soil brick making machine, please feel free to email us. HENRY has over twenty years of experience in developing and manufacturing compressed brick machine, selling dozens to Senegal annually. Reliable quality and excellent after-sales service ensure your peace of mind.

02. Next, we began to explore the soil conditions in central Senegal.

The soil in central Senegal is predominantly sandy, with a sand content of 83%, making it an ideal skeletal material for producing compressed blocks. This not only enhances the strength of the bricks but also reduces the risk of cracking during drying. However, the soil contains only 5.5% clay particles, a relatively low percentage. Low clay particle content can affect the plasticity of coconut soil brick, and Henry suggests adding a small amount of clay particles during production to improve soil cohesion. The soil has a pH of 5.5, making it slightly acidic. This acidity has little impact on soil raw materials containing cement. Furthermore, the soil has a very low organic matter content of only 0.56%, which is highly beneficial for interlocking stabilized soil blocks production.

Soils with high sand content are a “treasure trove” for producing soil brick, meaning the bricks will be dimensionally precise, high-strength, stable, and have a long service life. According to testing and research, adding about 10% cement to the soil can significantly enhance the strength of cocopeat soil brick, reaching 5.6 MPa, far exceeding the strength standards for compressed bricks set by the African Union for Standardization. Research by local handmade brick factories, which use local red clay and Portland CEM-II 32.5 MPa cement produced by local cement plants, has proven that the soil in central Senegal is ideally suited for producing high-quality compressed block.

So, how did the soil in central Senegal form?

The formation of the soil in this region is a complex process involving thousands of years of geological, climatic, and chemical reactions. Between 7,000 and 4,000 years ago, seawater repeatedly penetrated inland, forming estuaries in the area. The seawater contained sulfates, which reacted chemically with organic matter, producing large amounts of pyrite sediment. Between 4,000 and 1,800 years ago, the seawater slowly receded, exposing the large deposits of pyrite. This pyrite then oxidized to form sulfuric acid, which began to dissolve the shell layers, releasing elements such as silicon and aluminum, ultimately depositing as red soil rich in kaolinite and iron-aluminum oxides.

In 2017, Japanese architect Toshiko Mori used local red soil to press compressed block into the soil to build a new community in Sinthian, Senegal. The project, completed by 35 local workers over a year, features houses with compressed blocks and bamboo frames, providing excellent insulation and air circulation. Thanks to its outstanding design and the functionality of the compressed bricks, the community received an honor from the American Institute of Architects (AIA) in 2017, demonstrating the advantages of compressed brick in terms of environmental friendliness, local sourcing, and high functionality.

03. Next, we will shift our focus to the eastern region of Senegal (Kidira)

According to a 2024 study published in *New Forests*, firstly, the region’s soil is shallow, and topsoil resources are limited, making large-scale excavation unsuitable. Secondly, the soil has a balanced ratio of sandy to clay particles, leading Henry to determine that the soil is suitable for compressed block production without requiring any soil improvement treatment. However, the soil contains coarse particles such as gravel, and Henry recommends that it be screened before hand making bricks to remove gravel, small stones, weeds, tree roots, and other impurities. While the study indicates insufficient topsoil resources, the region possesses abundant deep-seated laterite resources, which is undoubtedly good news for compressed bricks manufacturers and builders.

Overall, the soils in eastern Senegal (Kidira), especially the deep red soils, are excellent raw materials for producing soil bricks. If you want to produce clay bricks locally, HENRY recommends conducting on-site soil verification.

The first step is to excavate the deep red soil.

The second step is to determine the specific ratio of sandy to clayey particles in the soil.

The third step is to determine the optimal moisture content and maximum dry density of the red soil.

The fourth step is to mix cement and soil in different proportions, press a compressed block, and test its strength.

The above verification provides detailed data on the local soil, which is crucial for achieving the optimal ratio of raw materials.

How were the soils formed in the eastern region of Senegal (Kidira)?

The soil in this region, formed on ancient bedrock, has undergone hundreds of thousands of years of weathering, incorporating quartz and aluminosilicate minerals. Furthermore, the local tropical climate has led to extensive leaching, resulting in red, iron-rich soils. The region is also home to numerous acacia trees, whose powerful root systems break down rocks and contribute to soil formation.

04. Next, we will analyze the soil conditions in the southern region of Senegal (Ngane and Velingara).

The soils in southern Senegal (Ngane and Velingara) are primarily ferruginous tropical soils and ferruginous alumina soils, with kaolinite as the main mineral component. These soils are stable and pose no risk of expansion. The iron oxides in the soil provide a natural curing agent for compressed blocks. Therefore, Henry believes that the soils in southern Senegal (Ngane and Velingara) are suitable for compressed block production. For local builders, we have two suggestions regarding compressed bricks production: First, regarding the selection of excavation sites, deep sandy soils are preferred in Ngane, while ferruginous tropical soils from the red soil region are preferred in Velingara. Second, during the production process, Henry recommends using 8%-10% cement. After production, the bricks should be cured for at least 25 days. Due to the high rainfall in southern Senegal, with an average annual rainfall exceeding 900mm, it is advisable to avoid the rainy season or construct rain shelters at the production site.

05. Finally, we will analyze and study the soils of northern Senegal.

Northern Senegal has a complex topography, primarily consisting of plateaus, slopes, lowlands, and forests. The soils are mainly classified into three types: sandy soils, balanced soils, and silty soils. Sandy soils, mainly found in the Firlo plateau region, are suitable for producing compressed blocks but lack cohesive particles. Balanced soils, located in the lowlands and mainly around ponds, have moderate cohesive particles and are suitable for compressed block production. Silty soils in the forest areas, with high silt content, are also suitable for soil brick production.

Northern Senegal also contains shell soils. This type of soil is primarily composed of quartz, contains a small amount of salt, and is hard, strong, and has low plasticity. Henry determined that this type of soil is unsuitable for producing soil bricks.

In the Podor region of northern Senegal, the “Maadi bakkeere Fuuta” project was launched in 2024. This project aims to build comfortable, healthy, and environmentally friendly housing using compressed blocks produced by a clay soil brick making machine. Encouraging local entrepreneurship, providing employment opportunities for young people, developing skills, and promoting eco-friendly architecture, the project has received support from the Podor Provincial Council and the Luxembourg Cooperation Agency.

By 2026, Senegal’s compressed block technology has rapidly developed, transitioning from a domestically commercialized building material to a national strategic material. From Elementerre’s initial production of clay bricks in 2010 to the current presence of eight large-scale compressed blocks manufacturers in Senegal, the local compressed bricks market is poised for further expansion, supported by the Podol housing project and restrictions on imported building materials. In the next 5-10 years, hand making bricks technology is expected to gradually become a mainstream building material.

Compared to concrete bricks, soil bricks offer economic benefits, comfort, environmental friendliness, and job creation, making them a building material officially recognized and actively promoted by the Senegalese government. Furthermore, international organizations such as the Dutch TNO, the European Union, the Luxembourg Cooperation Agency, and international NGOs are deepening their cooperation with Senegal on clay brick technology. In the future, builders who master interlocking stabilized soil blocks technology and produce high-standard soil bricks will undoubtedly dominate the market.

FAQ

01. What are the production costs of compressed block in Senegal? Are they cheaper than cement bricks?

The answer is that soil bricks have a significant cost advantage in Senegal, and the total cost of building a house using compressed bricks is 30%-50% lower than using concrete bricks.

Firstly, there’s the cost of raw materials. Senegal has abundant high-quality red soil, a natural and excellent raw material for producing compressed block. Using locally sourced materials and adding only 8%-10% cement, compressed blocks save a significant amount of cement compared to cement bricks.

Secondly, there are transportation costs. The raw materials for soil brick don’t need to be transported; the soil can be dug at the production site. In contrast, cement bricks require transporting cement, sand, and gravel.

Finally, there’s the construction aspect. Soil bricks, thanks to their unique structural design, require only a small amount of mortar during construction, while cement bricks require a large amount. According to our estimates, building a 100㎡ house using hand making bricks can save $1300-$1500.

02. How fire-resistant are compressed blocks?

Compressed earth blocks are classified as Class A non-combustible materials, exhibiting excellent fire resistance.

Earth blocks are made by pressing soil and cement together. Both soil and cement are completely non-combustible materials, so compressed stabilized earth blocks will not burn when exposed to fire, nor will they produce toxic gases. According to research and analysis by a Senegalese laboratory, a 20cm thick wall made of stabilized earth blocks can withstand 4-5 hours of fire resistance, while cement bricks may crack under high temperatures. Therefore, compressed block have excellent fire resistance, surpassing both cement bricks and traditionally fired bricks.

03. Can compressed bricks be made using only soil? Why is cement added?

The answer is that in the production of compressed earth blocks, soil alone cannot be used; an appropriate amount of cement must be added as a stabilizer.

Compressed earth blocks made solely from soil have poor water resistance and durability. Their strength drops drastically when exposed to rain, making houses built with such bricks highly susceptible to damage during the rainy season, and potentially even leading to collapse.

Adding cement to the soil causes a hydration reaction, significantly increasing the strength of the earth blocks while also enhancing their waterproofing and lifespan.

04. What equipment is needed to produce compressed block?

The core equipment for producing compressed bricks is the soil brick making machine, responsible for pressing raw materials into shape. Compressed brick machine are categorized by type: manual, semi-automatic, and fully automatic. If you require high output, strong pressing force, and higher quality clay bricks, HENRY recommends the HR10-10 automatic brick making machine. If your needs are high cost-effectiveness, diesel power, ease of operation, and lower output requirements, HENRY recommends the M7M1 clay soil brick making machine or HR2-25 solid bricks machine.

If you would like to learn more about different soil brick making machine models, please feel free to email us. Our team will reply to you as soon as possible.

05. What are some examples of houses built using soil bricks in Senegal?

In Senegal, there are countless examples of houses built using compressed blocks. Among these examples, the most representative is the Cinción Village Cultural Center, designed by a Japanese architect in 2017, which also won the 2017 AIA Honor Award. Secondly, in 2023, the local government built the Sambadia Kindergarten in Sambadia. Another project that has been underway since 2000 is the Nubian Dome project, which the Senegalese government has been building around Dakar. This large-scale project has already completed more than 2,000 homes and has won the World Habitat Award.