Structural and non-structural cracks

Structural cracks

Structural cracks occur from faults in design, construction or loading that affect the strength and stability of the structure. They are wide, progressive and often pass through the full thickness.

• Causes: overloading, differential foundation settlement, poor design or detailing, shear and bending failure, corrosion of reinforcement, earthquake, defective materials.
• Appearance: diagonal or step cracks near supports, vertical cracks in the middle of beams, cracks near column-beam joints, cracks at the soffit of slabs.
• Danger: may cause collapse. They need immediate investigation and repair.

Non-structural cracks

Non-structural cracks come from internal stresses in building materials. They do not affect the strength directly but allow water entry and look bad.

• Causes: shrinkage, thermal expansion, moisture movement, chemical reaction, poor curing, vegetation.
• Appearance: fine, hairline, random (map) cracks, in plaster, floors and walls.
• Remedy: cement slurry or sealant, fresh plaster, expansion joints.