Presence of Crack on external or internal wall surface may be a sign that there is some problem. An occurrence of the building cracks is often a subject that raises numerous questions. Cracks may appear either at the initial stage or with time.
Crack is a very vast topic to discuss, still we would try to cover as much is needed at this time.
Various types of cracks in building mostly take place during construction or after completion. Usually, building component develops cracks whenever the stress in the components exceeds its strength. The building cracks may be structural cracks1 or non-structural cracks depending on its nature. It may be vertical crack, horizontal crack, or diagonal crack, etc.
Let us discuss the cause of cracks in your house.
Causes of Cracks in your house
1. Moisture changes
In India, houses are mostly made of concrete, bricks, mortar etc. These construction materials are natural water absorbing components. When they absorb moisture, they expand and on drying, shrink. Hence develops the cracks in walls due to change in moisture. Consequently, if building materials used possess expanding or contracting natures, then existing cracks increase or sometimes new cracks also get formed.
2. Change in Temperature
Cracks in buildings are also contributed by temperature fluctuations and the changes induced by it in building materials. We use the materials like concrete, mortar, burnt clay bricks, etc. for the construction of house. They expand on heating and contract on cooling depending on their properties. Due to the expansion and contraction of materials, internal tensile stresses are set up in the component of the house. Hence it develops the wall cracks due to change in temperature. This change in temperature of materials is also known as thermal movement. These types of cracks are observed on the exterior of the house.
3. Elastic Deformation
This would be too technical for you to understand. Structural components of a building such as walls, columns, beams and slabs, generally consisting of materials like masonry, concrete, steel, etc, undergo elastic deformation due to load in accordance with Hooke’s law i.e. The amount of deformation depends upon elastic modulus of the construction material, magnitude of loading and dimension of the components.
It is the structural components of your building2 which can fall prey to this phenomenon. Cracks in building require third party property inspection prior to building the house. This would save your valuable time to a significant extent.
4. Creep Movement
The construction materials result in deformation due to sustained load. The stresses are developed in the component of house due to slow time-dependent deformation and hence develops the cracks in walls. The tendency of the materials to deform permanently under stress is also known as creep movement.
Creep movement depends on many factors, such as: Water cement ratio in mortar and concrete, Use of admixtures in mortar or concrete, temperature and humidity etc. It increases with increase in water content, cement content and temperature.
There is always a chance of human error in building a house. While working, the ratio of mortar to concrete might be wrong and the admixtures used in either mortar or concrete could have been problematic. Any or all of this can cause your house to deform as the sustained load creates concrete cracks. The materials, besides crack in the house, can be deformed permanently leading to non-structural cracks. Arranging for home inspection by a specialists’ team can always help you identify the predisposing factors and take necessary steps.
5. Corrosion of Reinforcement
A typical character in Indian house is the use of steel. Most of the cracks observed in recent RCC building are due to the corrosion of steel. Initially, they do not pose any threat to the safety of the structure. Low quality of the steel reinforcement, poor grade of concrete, inadequate cover to reinforcement and poor workmanship both are equally responsible for this. The iron oxide film is produced on the bar which increases bar’s volume, thus setting up internal stress in concrete. Hence develops cracks in house due to corrosion. Such cracks can do further damage as these invite moisture in. In addition, if the concrete is also cracked, the damage chances are higher.
6. Movement due to Chemical Reaction
Due to chemical reactions, materials of construction results in the appreciable increase in the volume. The internal stresses are set up in construction materials which may result in outward pressure and hence forms the wall cracks. The materials involved in chemical reaction also get weakened in strength.
Sometimes, structural cracks on the walls are a result of chemical reactions that occur among the ingredients. For example, the soil that has been used can contain soluble sulphates. These sulphates often react with the cement which contains tricalcium aluminates and hydraulic lime in presence of moisture. Don’t worry – this is not another science check. Just know this much that the resultant chemical has a large volume as it tends to expand. Now you can easily imagine, when materials want to expand, what would they do? Answer is formation of Building cracks. Mostly, these are plaster weakening and masonry cracks.
7. Soil Settlement
Soil settlement is a vast topic and it is slightly difficult to make you understand. As per handbook based on causes of cracks3 in building, Shear cracks in building occur when there is large differential-settlement of foundation either due to unequal bearing pressure under different parts of the structure or due to bearing pressure on soil being in excess of safe bearing strength of the soil or due to low factor of safety in the design of foundation.
Your house is based on soil which might expand and shrink with the change in temperature and moisture content in it. This causes change in soil volume and foundation movement. Result is again the undesirable cracks on the walls of your house.
8. Growth of Vegetation
Existence of vegetation, such as fast growing trees in the vicinity of building or structure can sometimes cause cracks in walls due to expansive action of roots growing under the foundation. The plants begin to grow in the fissures of walls, and If these plants are not removed well in time, it develops the wall cracks in house.
Apart from all these causes, inadequate curing in any of structure may be made of masonry or RCC can be a cause for cracks in the building.
Cracking in structures is a common defect in a home whether it is new or old. Several factors other than the ones mentioned above can be responsible for cracks on the walls such as design of the house, workmanship of the people involved in construction, and building materials’ quality, etc. Not all of these are in your hand. But you sure can take preventive measures.
Crack repair is not always an expensive or tedious job. For repairs and remedies to be effective, it is essential to evaluate the causes and nature of crack in building. Apart from this, it is true that that minor cracks can turn into bigger cracks to threaten the structural integrity of your home, and that every crack should be taken a look at by a professional. So you can hire professional services to get home inspection that will help you out with 3D of issues – Detect & describe the issue and Direct the solution. They will suggest the solution as per issue in your home.