Cracks are those which result from incorrect design, faulty construction or overloading and these may endanger the safety of a building and their inmates. Cracks occur mostly due to internally induced stresses in building materials. These cracks normally do not endanger the safety but may look unsightly, create an impression of faulty work or give a feeling of instability.
Nature of problem:
A crack in a concrete or wall would allow water from the outside penetrate through it, these water get stagnant inside the crack which accelerate the mold and fungus inside the crack. If the conditioned remains untreated the dampness cause major structural damage to your building materials.