Inter-unit water leakage is one of the most common disputes in Singapore's high-density housing. Whether you are the affected unit below or the source unit above, knowing your responsibilities — and acting quickly — prevents the situation from escalating.

Who Is Responsible?

In Singapore, the general principle is that the owner of the unit from which water originates is responsible for repairs. This applies whether the leak comes from a burst pipe, failed waterproofing, or damaged fixtures within your unit.

💡 Under the Building Maintenance and Strata Management Act (BMSMA), the upper unit owner is presumed responsible for leakage unless proven otherwise.

If You Are The Affected (Lower) Unit

  1. Document everything — photograph and video the leak, staining, and damage immediately
  2. Inform your upper neighbour in writing (WhatsApp with read receipt is acceptable)
  3. Contact your building management — for condos, the MCST; for HDB, your Town Council
  4. Request a joint inspection with the upper unit owner and a qualified plumber
  5. Keep records of all communications, inspection reports, and repair quotes

If You Are The Source (Upper) Unit

  • Do not ignore the complaint — delayed action increases your liability
  • Engage a licensed plumber or waterproofing contractor to investigate promptly
  • Common sources include: failed bathroom waterproofing, cracked pipes, overflowing fixtures, and leaking AC condensate trays
  • Carry out repairs promptly and provide documentation to your lower neighbour

⚠️ Ignoring a leakage complaint can result in a mandatory order from HDB or MCST, legal action for damages, and repair costs far higher than early intervention.

Common Causes of Inter-Unit Leakage

  • Bathroom waterproofing failure (most common cause)
  • Cracked or burst concealed pipes
  • Toilet pan or shower tray seal failure
  • Air-conditioning condensate overflow
  • Grout deterioration in wet area tiles

The Fix: Waterproofing Restoration

In most cases, the solution involves hacking the affected wet area tiles, reapplying a 3-layer waterproofing membrane, and re-tiling. This is the only permanent fix — surface sealants are temporary and will fail again.

Our team provides leak detection, waterproofing restoration, and full documentation for dispute resolution. We work with both units to identify the source accurately before recommending repairs.