What is a corner or wedge crack?
The majority of slab-on-ground foundations will develop what are called corner cracks or wedge cracks. The name comes from the fact that these cracks develop at or very close to the outside corners of the foundation, frequently in the shape of a wedge.These cracks develop as a result of the expansion of the brick veneer when it is warmed by the sun. When the temperature of the brick veneer rises, the brick veneer wall expands in length and pushes or slides against the slab surface. The southwest side of a home is typically the side that gets most of the sun and heat exposure. At the end of a brick veneer wall at an outside corner of the slab, there is nothing to push back and the concrete cracks at each side of the corner forming a wedge. These cracks do not indicate anything unusual about the foundation.