An occurrence of the building cracks is often a subject that raises numerous questions. Cracks may appear in structures, either at the initial stage or with time. It should first of all be accepted that building cracks of some type are unavoidable in any structure.
Occurrence of various types of cracks in the building mostly takes place during construction and/or after completion. A building component develops cracks whenever the stress in the components exceeds its strength. Stress in the building component is caused by externally applied forces/loads. Occurring of cracks after completion or during the service life may be due to additional super imposed loads (any applied load other than self weight of structural element) than considered while designing, is a common phenomenon.
The building cracks may be structural cracks or non-structural cracks, it may be thin cracks, medium cracks, wide cracks or crazing. It may be straight cracks, toothed cracks, stepped cracks, map pattern cracks, vertical crack, horizontal cracks or diagonal cracks. We have already explained classification of cracks based on their nature, width, and shape. Read more on Types of cracks.
The commonly used building material namely masonry, concrete, mortar etc. are weak in tension and shear. Consequently the stresses of even small magnitude causing tension and shear stresses can lead to cracking. Internal stresses are induced in the building components on account of thermal movements, moisture change, creep, elastic deformation, Corrosion in reinforcement, chemical reactions, poor construction practices, poor structural design and their specification, wrong selection of material, poor maintenance, quality of materials etc. We have previously explained the various reasons which may cause cracks in building. Read the causes of cracks in house.
Occasionally, plastic shrinkage cracks also occur during its plastic state due to the rapid moisture loss. To know more about the size, shape, causes and remedies of these cracks, read plastic shrinkage cracks.
Frequently, cracks also occur if the component of the building or house has an inadequate reinforcement steel and/or inferior concrete quality. To know more about the concrete cracks, read types and summery of cracks in concrete column and cracks in concrete beam. Sometimes these cracks may also cause corrosion in concrete which may be the reason of building collapse. Here we do not discuss the reasons of building collapse in detail. But If you want to know more about the causes of failures of building, read collapse of building.
All these above described phenomenon causes dimensional changes in the building components. If Dimensional changes movement is restrained then stresses are induced and whenever these stresses (tensile or shear) exceed the strength of material, cracking occurs.
Generally movement is restrained due to following reasons
- Interconnectivity of various members
- Resistance between the different layers of the components
Whether the building cracks occur in brick work or in concrete, it becomes the reason of maintenance and repair of house. Hence it is necessary to take preventive measures at the time of constructing a house, or when cracks appear in the house, do repair it as early as possible because it may cost you a fortune in the future. Read the tips to repair concrete cracks. Also know the methods of investigating the cracks and procedure to repair masonry cracks.
To sum up care should be taken while constructing your house and also even after construction is complete. Periodical inspection and maintenance should also be carried out regularly.