What is the reason for the house cracking?

Because of the different temperature difference, most houses are built by combining reinforced concrete with brick walls. Their respective expansion coefficients are different, and different tensile stresses are generated under the same temperature change, resulting in wall cracking. Just set expansion joints.

concrete: refers to the general name of engineering composite materials in which aggregate is bonded into a whole by cementing materials. Generally speaking, the word concrete refers to cement as cementing material and sand and stone as aggregate; Cement concrete, also known as ordinary concrete, which is mixed with water (including additives and admixtures) in a certain proportion and obtained by stirring, is widely used in civil engineering.