Dear ndevendra
Cracks in building are a common occurrence and these occur due to carelessness of contractor, mason, and ignorance of house owner and using of inferior materials in construction. It is important to understand the causes and the measures to be taken for their prevention. Before doing any repair of cracks, make sure that the cracks are stabilized or not i.e. widening further and repair the cracks with the help of expert mason as per detail given in the article at the website gharexpert.com link given below.http://www.gharexpert.com/articles/Cracks-1468/How-To-Repair-Cracks_0.aspx for further more details you can read articles at www.gharexpert.com website.and article link is:
http://www.gharexpert.com/home/new_categorylist.aspx?PL=2&CATID=1371
http://www.gharexpert.com/home/HOW_TO_PREVENT_CRACKS_IN_BUILDING.aspx