Cracks aren’t uncommon in earth construction.
In cob construction, the walls have a tendency to crack due to several factors such as
-direct exposure to sunlight or rain
-proportions of sand and clay
-consistency of the mix
-air temperature and humidity
The are two types of cracks- surface and structural and when structural cracks
occur,there is a need to be worried about.
-The cracks are covered with wet sacks which are to be maintained damp
-Rectangular boxes are chiselled on the cracks and filled with a mixture of earth,
lime and fermented jaggery solution with straws and human hair for added strength
-Small bricks are made out with the help of the formwork
-The bricks are filled in the cracks and left to dry while being covered with wet sacks
Another method we tried when some of the repaired cracks started to crack again was,
making 2.5cm deep holes in the chiselled cracks after a course is done and fitting in
calatropis for reinforcement after which the second course is laid in the cracks.