Water leakage case
Water Leakage Project at Ka Fat Building, Carnarvon Road, Tsim Sha Tsui, Kowloon
A Heavy Rainstorm Revealed the Truth Behind Ceiling and Wall Seepage
"My bedroom ceiling is mouldy, the wall plaster is peeling off, and it gets worse every time it rains… What am I supposed to do?"
This was the heartfelt cry from the owner of Flat B, 7th Floor, Ka Fat Building, 22-24 Carnarvon Road, Tsim Sha Tsui, Kowloon.
One day, he noticed water stains starting to appear on his bedroom ceiling. The paint on the walls began to flake off. Even his wooden bed frame and wardrobe started to grow mould. He tried wiping it clean and repainting, but the problem never went away – especially when it rained, the leakage became noticeably worse.
"I've lived here for so many years. Why did this suddenly happen? Where is the water coming from?"
That feeling of watching your own home being slowly damaged by water, with no idea how to stop it – we understand it completely.
Two Inspections to Uncover the Truth！！
On 3 June 2026 and 9 June 2026, the expert team from Silver Surveyors visited the subject flat twice to conduct a comprehensive technical investigation. Why twice? Because we deliberately chose one sunny day and one day after heavy rainfall to perform comparative tests – this was the key to determining whether the leakage was related to rainwater.
What did we discover?
1. Infrared Thermography Revealed Concealed Moisture Zones
During the first inspection (3 June, fine weather), we found significant moisture retention in the bedroom ceiling near the external wall and the party wall. In the second inspection (9 June, after two days of accumulated rainfall totalling 120.2 mm), the amount of moisture in the same area had increased markedly.
Similarly, the bedroom wall near the external wall and party wall also showed substantial moisture, which worsened after the heavy rain. In contrast, the area near the window frame showed no moisture – an important clue.
2. Conductive Moisture Meter Testing Confirmed the Severity
We set up multiple moisture measurement points in the affected areas. The results showed:
Ceiling location: The highest moisture reading reached 84.2% (extremely high level), and overall readings rose significantly after the rain.
Wall location: Some measurement points recorded moisture levels as high as 99.9% (saturation point), with a dramatic increase after the heavy rain.
Reference location (living room wall): Moisture levels were only 8.8% – 12.6%, well within the normal range.
3. Water Sample Analysis Identified the Nature of the Water
We collected water samples from both the ceiling and the wall for chemical analysis. The results showed that both samples had a salinity of 0.00 p.p.t and tested negative for ammonia – meaning the infiltrating water was fresh water, ruling out the possibility of discharge pipes or saltwater mains.
4. Visual Inspection Documented the Extent of Damage
The ceiling showed obvious water stains, mould growth, and hollow/delaminated areas (separation of plaster from the structural substrate). The wall exhibited cracks, peeling paint, water stains, mould, and hollow areas. The wooden skirting board below, as well as the built-in bed frame and cabinet nearby, were also affected, showing water stains and mould.
Comprehensive Conclusion: Source Traced to the Building's External Wall and Party Wall
By synthesising all test results, we reached the following conclusion:
There is evidence and indication that the building's external wall and party wall are leaking, with water migrating into the bedroom ceiling and wall of the subject flat.
How can we be certain? Because:
The leakage worsened significantly after rainfall, showing a strong correlation with precipitation;
The affected areas were all located near the external wall and party wall, not near the window frame or neighbouring units;
The water samples tested as fresh water, ruling out drainage pipes;
The affected areas in the subject flat are not adjacent to any other unit, eliminating the possibility of leakage from neighbours.
"So it was the external wall all along… It wasn't my plumbing, and it wasn't the neighbours upstairs or downstairs."
When we presented our findings to the client, he finally breathed a sigh of relief. The mystery that had troubled him for so long now had a clear answer.
How Much Damage Was Done? A Clear Assessment
Based on our detailed calculations, the total loss and estimated repair cost for the subject flat amounted to:
HKD $85,719.98
This covered:
Cutting out and removing deteriorated concrete, followed by anti-rust treatment for exposed steel reinforcement
Reinstatement of plastering and emulsion paint finish
Replacement of the affected aluminium false ceiling
Replacement of wooden skirting boards and the damaged built-in bed frame with cabinet
Final cleaning and disinfection
Note: Due to prolonged exposure to moisture, the affected areas had developed extensive mould growth. We recommend engaging a professional cleaning company to carry out thorough disinfection to safeguard the occupants' health.
What This Case Teaches Us？
Leakage problems are not always caused by a neighbour or by your own pipes. Sometimes, the source lies in the building's external wall or common structure. These cases are particularly tricky because the cause is invisible to the naked eye, and the symptoms often only become noticeable when it rains – by which time the damage may already be significant.
At Silver Surveyors, we let science speak and integrity guide us. By conducting comparative inspections under different weather conditions, and deploying multiple techniques including infrared thermography, moisture metering, and water sample analysis, we cross-validate every finding to uncover the truth.
If you are facing a similar ordeal – mouldy walls, peeling ceilings, or water seepage that worsens every time it rains – please reach out to us. Let our expertise and science identify the root cause and protect your home.
Expert Qualifications Endorsement
This report was signed and confirmed by Mr. Leung Ka Chun, Managing Director of Yin Jin Consultants & Gongzheng Limited. As a Chartered Institutional Surveyor (MRICS), Chartered Builder (MCIOB), and Chartered Building Engineer (MCABE), Mr. Leung possesses extensive experience in building diagnostics and surveying, ensuring the professional authority of the investigation.
Silver Surveyors | Precision in Investigation, Integrity in Service
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（Infrared scanning of affected ceiling locations）
（Infrared scanning of the living room wall of the survey unit）
（Plan view of the location of humidity monitoring points on the ceiling in the affected area）
（Infrared scanning of the affected wall location）
（Salinity and ammonia test results at the affected location 1）
（Plan view of humidity detection point location on wall B in the affected area）
（Plan view of humidity monitoring point locations on the living room wall (near the exterior wall) of the surveying unit.）
（Salinity test results and ammonia test results of the wall at location 2）
（Leakage location 1: Exterior wall of the building）
（Leakage location 2: Public wall of building 2）
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