Use of AAC blocks to construct a wall is not the reason of cracks unless blocks quantity is very bad. There are many reasons which cause cracks like crazing and spider web pattern, such cracks are observed at many places. Here are the reasons which may be the cause of cracks on your wall:
* Shrinkage in blocks or poor quality of blocks may also cause a crack in a wall.
* Use of higher grade of cement to make mortar.
* Use of rich cement mortar i.e. the cement content is higher than specified in the design mix.
* Use of very fine sand to make mortar i.e. higher silt content or use of sand which is not graded properly.
* Higher water cement ratio in mortar mix.
* Improper curing. * Poor workmanship.
* Higher thickness of plaster.
* Early application of putty i.e. putty is applied just after curing.
* A temperature at the time of application of plaster. i.e. shrinkage cracks are more prone in summer season than the winter.
* Use of higher grade of cement to make mortar.
* Use of rich cement mortar i.e. the cement content is higher than specified in the design mix.
* Use of very fine sand to make mortar i.e. higher silt content or use of sand which is not graded properly.
* Higher water cement ratio in mortar mix.
* Improper curing. * Poor workmanship.
* Higher thickness of plaster.
* Early application of putty i.e. putty is applied just after curing.
* A temperature at the time of application of plaster. i.e. shrinkage cracks are more prone in summer season than the winter.
Humidity at your location. i.e. relative humidity in the coastal region is high through the year hence this area is less prone to the cracks.
Continuous vibration or frequent hit by a hammer for nailing may also be a reason of cracks in a wall.
