The short answer to this is predominantly ‘Thermal Expansion and Contraction’ caused by temperature fluctuation. Different building materials expand and contract at different rates; and yet others are more resistant to cyclic movement altogether.
It is an unfortunate fact that many Builders, Architects, and Developers today are still happy to trust that a traditional cement based render system will provide durable façade protection for many years. The simple truth is that it won’t. Why is this the case?