“In response to a recent post on the blog, I searched for Earthen Buildings East Africa to look for photographs and came across the following link:
[large file warning to those with slow Internet connections]
You may judge it worth publishing on your site as it, for a thesis, examines the properties of building bricks made from various materials for low-cost building in Africa but could be used anywhere as demonstrated by tests in central Tanzania with parallel results from California.
It, rather surprisingly, shows the “Best bricks for the Buck” are made from clay stabilised with lime, provided you protect them from rain and particularly floods. These are ideal for those who cannot afford or do not want to use cement.
Lime is the traditional stabiliser, used on the East African coast for 2 or more millennia, with dead coral blocks and coral rag.
I think we can regard lime as a sustainable material as, in Kenya, the major supplier uses their own plantation timber for firing the kilns.”
From the Conclusion of ANALYSIS OF STABILIZED ADOBE IN RURAL EAST AFRICA By Grace Ying Yu Chen
“Because flooding is not common in Itigi, the 7% lime with clay bricks, which performed well in all tests except water submersion, is recommended for future construction in Itigi. Using 5% cement+5% lime instead of 10% cement decreases the cost of bricks by 23%. Using 7% lime with clay instead of 10% cement decreases the cost of bricks by 61%. The 7% lime with clay mix is the most affordable choice.
Thanks to Tony for notifying us of this report. Our blog benefits greatly from reader contributions.
Note: Lime can also be used to stabilize earthbags where moisture problems are a concern.
Related: Eleven Earth Floor Methods