Interlocking Soil Stabilized Blocks (ISSB) is a brick technology that has existed for hundreds of years and is just making headway in Sub-Saharan Africa. Makerere University in Kampala along with support from organizations like Good Earth Trust are doing much to develop and promote its use. The interlocking feature to the Soil Stabilized blocks was in fact developed at Makerere!
In the summer of 2009, UNHABITAT and Good Earth Trust published a document promoting the use of these bricks. They visited many buildings using the technology, including, BULA’s newly constructed St. Kizito Primary School! They deemed the structure a model for the blocks’ use and then used them in the publication for succesful use of the blocks.
The blocks are made with a a mixture of soil, cement and water compacted with a manually operated machine. The benefits of the use of these blocks are great and include:
Environmental – breaking away from the common practice of firing bricks, the impact of deforestation and on the wetlands is greatly reduced.
Structural The compression of the bricks creates a strong and sturdy block. The uniformity and the interlocking feature of the brick provides great stability to the structure.
Educational – Introducing this technology to the community provides a new skill set while also promoting environmentally conscious practices in construction and decision making.
Aesthetic – Building with these blocks creates more visibly attractive building. Pride in one’s school has a tremendous effect on morale and motivation in the community and among students.
During the construction of St. Kizito, we had 2 machines on site producing up to 500 bricks a day. The soil excavated from the holes dug for the water tank and the latrines was used to make the bricks. The benefits described above were actualized in the project as evident in the school’s beauty, the skills passed on, the productive use of soil, and the firewood saved.