Among the many factors of deterioration of building, poor maintenance and neglect are major factors. Users are reluctant to take up the maintenance work for the following reasons.
1. Lack of maintenance / repair knowledge.
2. Tendency to save money during maintenance related repairs.
3. Inferior quality of materials used due to shortage of fund resulting into ineffective maintenance or repair.
4. Reluctant to adopt new material due to high cost and unknown track record of such materials.
5. Tendency to go for short-term gains.
7. Reluctance in appointing proper and experienced Consultant to save fee and relying on incredulous contractors.
There have been some building collapses, which were quite healthy, due to indiscriminate additions and alterations done by so-called interior designers (decorators) at the instruction of the Owner. The common alterations / additions made are alteration to window canopies, additions of walls on window canopies, enclosing of open balconies, conversion of a dry area into toilet / bath, addition of heavy weights on weak or inadequate structural elements, etc. All these additions / alterations take place when entire building or part changes hands.
It is always the case that no engineering advices are taken before any such changes in the building or its part. Careless modification can lead to leakages or serious structural damages.
Many times the building elements are forced to take load more than what they are designed for. Temptation of users to occupy more and more area without bothering about the effect on building element jeopardizes the safety and durability of the building. In case of change in the purpose of use, say from residential to commercial, it is likely that the load on entire building or part will increase or change thus causing the damage.
Natural Calamity like rain:
Reinforcement steel bars have to be protected against corrosion, caused due to reaction with oxygen, moisture and chlorides in the atmosphere, ground water or sub-soil. Reinforcement steel bars are generally protected by providing concrete cover around them or by providing a protective coating on steel.
Resistance against corrosion of reinforcement steel and the degree of protection to reinforcing steel is greatly dependent on the many factors. Mechanism of corrosion of steel is an electro-chemical process and for this, presence of moisture and oxygen is necessary. Metal (embedded steel rods in RCC) that gets converted into rust (corrosion product) may occupy 6 to 8 times the original size of steel. This growth creates tensile force within the concrete mass surrounding the reinforcement steel. Since concrete is brittle and weak in taking tensile or expansive forces, it cracks and spalling of concrete takes place.
Most of the building structures have a very conductive atmosphere for a permanent problem for leakage or seepage through peripheral portion of window and exterior skin walls. Air pressure results the forced entry of rain water inwards through unprotected opening or through joint, seal imperfection in the window sill or frame and gap of concrete and masonry.
Water is the primary vehicle for the diffusion of all aggressive ions, such as chlorides and sulphates, into the concrete mass. Any repair strategy approved and adopted will not yield any good result unless the major source of deterioration is not addressed in the repair strategy and planning.
Due to wind pressure, seasonal and daily temperature variation, chemical reaction in saline coastal atmosphere, moisture variation in humid area, corrosion of metal (rusting of steel in RCC), root of growing trees, moss / lichens / fungi growth, etc. the building undergoes fast aging and comes to repair stage.