Last reviewed 16 Sept 2026 · 7 min read
Need for maintenance
Maintenance is the work undertaken to keep, restore or improve a building and its services to an acceptable standard, so that it performs its function safely over its intended life.
- Prevents deterioration and extends service life.
- Ensures safety of occupants and functional performance.
- Preserves appearance and value; reduces life cycle cost (early repairs are cheaper than major rehabilitation).
Types of maintenance
| Type | Description |
|---|---|
| Routine (day-to-day) maintenance | Regular minor works — cleaning drains, replacing fittings, minor plumbing and electrical repairs |
| Preventive (planned/scheduled) maintenance | Carried out at predetermined intervals to prevent failures — periodic painting, waterproofing renewal, servicing of pumps and lifts |
| Condition-based (predictive) maintenance | Based on inspection/monitoring of condition |
| Corrective (breakdown) maintenance | After a failure is noticed — repairs to leaking roofs, broken pipes |
| Emergency maintenance | Immediate action for safety — collapse risk, flooding, fire damage |
| Annual repairs | Periodic works in government practice — whitewashing, colour washing, minor repairs |
| Special repairs | Major repairs/replacement beyond routine — re-roofing, replacing floors, strengthening |
Causes of deterioration
- Moisture — rain penetration, rising dampness, leakage from services.
- Temperature variations — thermal expansion and contraction.
- Chemical attack — sulphates, chlorides, carbonation, acids, efflorescence.
- Corrosion of reinforcement — loss of alkalinity (carbonation) or chloride attack; rust expands, causing cracking and spalling.
- Biological agents — vegetation, fungi, termites.
- Foundation movement — differential settlement, swelling/shrinkage of clays.
- Overloading and change of use; vibration; earthquakes, fire.
- Poor design, materials and workmanship; lack of maintenance.
Cracks in buildings
Classification
- Structural cracks — due to faulty design, overloading or foundation failure; may endanger safety.
- Non-structural cracks — due to internal stresses from moisture and thermal movements; usually not dangerous but allow water entry and look unsightly.
- By width: fine, medium and wide cracks; by pattern: vertical, horizontal, diagonal, map (random) cracking.
Causes of cracks
| Cause | Typical cracks |
|---|---|
| Moisture movement (reversible/irreversible) | Shrinkage cracks in plaster and masonry; irreversible expansion of fresh bricks |
| Drying shrinkage of concrete and mortar | Map cracking; cracks at junctions of different materials |
| Thermal movement | Cracks at roof–wall junctions (horizontal cracks below slabs), long walls without expansion joints |
| Elastic deformation | Cracks where walls of different stiffness meet under load |
| Creep | Deflection-induced cracks in walls under beams |
| Foundation settlement | Diagonal cracks, wider at top or bottom, through masonry and openings |
| Chemical reactions — sulphate attack, corrosion, alkali-aggregate reaction | Cracks along reinforcement, expansion, map cracking (AAR) |
| Vegetation — tree roots | Cracks in walls and foundations near trees |
| Plastic shrinkage/settlement in fresh concrete | Surface cracks soon after placing |