Water Leakage | Causes of Water Leak in Building

Water leakage or water seepage is one of the major causes of common building defects. If water leakage can be prevented, almost 80% building defects can be eliminated. The locations and causes of water leakage in building is given in the below chart.


Water Leakage Location & Causes

Water leakage is generally found in some specific locations of a building. The location of water leakage and possible causes of the leakage is discussed below.


Location of Leakage or Seepage Possible Causes
Underside of roofs (such as flat roof, podium roofs) and bottom of light wells
1. Damage or deterioration of waterproofing layer.
2. Leakage at access doors or top hatch doors.
3. Deterioration of corrugated steel roofing materials and joints.
4. Defective enclosure for water tanks.
Ceiling with internal areas above
1. Leakage from bathroom or kitchen above usually caused by seepage from fitments, bathtubs, shower trays, buried pipes or drains due to improper construction of joints, installation of sealants or occurrence of cracks.
2. Waterproof cement rendering underneath floor tiles for the floor above not installed/specified or such waterproofing features damaged by installation of sockets or conduits.
3. Mal-function of waterproofing in nearby external features such as balconies or external walls above.
1. Water penetration through external wall defects such as cracks, joints, honeycombs, spalling, weak points, holes, punctures, leftovers of debris, and movement of external wall components.
2. Water penetration through defective external wall finishes such as loosened mosaic tiles, cracked ceramic tiles & paint surface; through poor cladding or curtain walls constructions or weaknesses in water-resisting components.
3. Water leakage through partition walls between units of pre-fabricated elements or between buildings.
1. Defective bathroom fitments such as bathtubs, shower trays or hand wash basins, or the improper installation of pipework or necessary sealants.
2. Temporary floods and overview.
3. Seepage from defective pipe-works or sanitary fitments.
1. Improper fillings around frames.
2. Deformation of frame, defective gasket, sealant or putty for window glass setting or frames.
3. Air conditioning box or platform tilting inwards.
4. Insufficient sealant around air conditioning units.
1. Inadequate or damaged waterproofing tanking.
2. Deterioration of water stops at construction/movement joints.
Buried or underground drains or pipes

1. Seepage through defective joints or pipes caused by poor installation or differential movements / settlements, movement of building structures or ground or water table.

2. Corrosion of pipes at junctions with floors or walls.
3. Invasion of water into conduits and distribute throughout the network.
4. Blockage leading to excessive pressure built up.
5. Attack by rodents or roots of plants.
Exposed (or in pipe ducts) supply pipes or drains
1. Inadequacy in design of drains such as insufficient diameter of drains, bends being too sharp.
2. Blockage of drains by rubbish/sand collected in the system especially in bends or traps.
3. Insufficient number or deterioration of brackets leading to hammering and breakage of supply pipes.
4. Blockage of open joints such as hoppers of down pipes by plants or rubbish.
5. Unauthorized additions overloading the drainage system.


7 thoughts on “Water Leakage | Causes of Water Leak in Building”

  1. My bathroom is causing a leakage on the floor below we have removed the floor tiles done waterproofing then laid cement structure and again waterproofing but the leakage hasnt stopped the entire wall tiles have also been removed and all connections checked that connect to the shower and washbasin ..
    But as we fill the water on the cement to check if water is dripping or not It drips on the floor below immediately
    So please advice are we missing onto something

    • Is there a bathroom below or any other room? Is there a false slab in the bathroom below? Check the outlet/grating hole that is used for water removing and also the outlet pipe of the commode where connected with the main vertical pipe. Are you saying that water is dripping through the main roof slab? It is quite improbable.

  2. Roof leaks are often hard to discover the source. The water can travel down a roofing joist and damage the ceiling inside a considerable distance from the actual leak.

    It’s often necessary to replace the entire roof to fix one small leak.

  3. Hi
    In order to understand the cause of leakage in a multi storeyied building whom do we have to consult? Could you suggest an agency who can help.



Leave a Comment