Brick-making Rwandan style

Most houses in the countryside in Rwanda seem to be built with mud bricks made of mud dried under the sun.   The process is fairly simple.  

Dig up and break up red coloured mud from the ground, creating a big gapping hole.  Mix with water.  

Place a rectangular mould roughly 30 cm x 15 cm x 15 cm on the ground.  Fill the mould with the mixed mud.  Remove the mould.  Let the mud brick dry under the sun.  Use.  

The dried mud brick feels hard.  But it crumples easily and gradually melts when it rains.    The house starts to crumple.  Hence a house built with mud bricks needs constant repairs. 

I was told each mud brick costs around 20 Rwandan Franc, which is equivalent to 0.015 USD. 

Some, a much smaller number of them, are built with fired bricks.  These are much smaller.  Roughly 20 cm x 8 cm x 5 cm each.  

The mud I have seen come from a river back, much finer and smoother.  

Again, it is mixed with water, and put in a mould, and dried under the sun.  

But then, they are stacked up to form the structure of a rudimentary kiln, leaving big holes underneath for the fire.  The stack of bricks is the kiln.  There is no other structure.

A thin layer of mud is placed over the structure.  Then a fire is lit and fed by wood under the the bricks, for several hours.   

When the kiln cools, the thin layer of sealing mud cracks and otherwise removed.  And the fired bricks can be taken away to be used.  When the bricks are removed, the kiln is no more. 

The fired bricks are much more robust and durable. They are also much more expensive, at 40 Franc each.  Considering their much smaller size, fried bricks are 10-15 times more expensive, for the same volume of bricks.  No wonder they are used much less often.