What are the common causes of diagonal cracks in walls and how can they be effectively repaired?

Common causes of diagonal cracks in walls include foundation settlement, structural movement, and water damage. To effectively repair these cracks, it is important to first address the underlying issue causing them. This may involve fixing any foundation issues, stabilizing the structure, and ensuring proper drainage. Once the root cause is addressed, the cracks can be repaired using methods such as filling with epoxy injection or applying a patching compound. It is recommended to consult with a professional contractor for proper diagnosis and repair.