Inspection Record 01 · Kuala Lumpur · September 2026
The leak was fixed.
The leak was fixed.
The smell stayed.
A condominium in Kuala Lumpur, thirty years old, with a leak from the unit above that had been stopped and a kitchen that had been scraped, patched and repainted a month earlier. The musty odour never left. In two hours on site, the instruments explained why.
Scroll
2 hrsOn site, room by room
4Rooms air-tested
~1000Wettest slab reading (0 to 1000)
5Instruments used
Ultraviolet surface screening, thermal imaging, calibrated moisture metering and indicative air-quality monitoring, read against the Malaysia DOSH Industry Code of Practice on Indoor Air Quality (ICOP IAQ 2010) and the DOSH Guidelines on Control of Molds Contamination and Remediation (2019).
The brief
Repaired. Repainted. Still wrong.
The owner, Ms. Lim, rents the unit out. Her tenants had lived with a musty smell for months. A contractor had already scraped the visible mould above the kitchen cabinet, replaced a few panels, applied a chemical and a membrane, and repainted. The leak upstairs had been stopped. And yet the smell was as strong as ever. She asked Cleanaholics to find out why, honestly, before spending anything more.
How the unit was assessed
Measured, not guessed.
A room-by-room inspection of the whole unit, with the tenants and the owner’s husband present, combining what can be seen and smelt with what only instruments can show.
- Ultraviolet screening. A 365nm lamp reveals surface residue consistent with microbial or organic matter that is invisible under normal light.
- Thermal imaging. A HIKMICRO thermal camera checks for active water ingress and retained moisture behind surfaces.
- Moisture metering. A Protimeter reads retained moisture in concrete on a 0 to 1000 scale: Dry to 100, At Risk to 200, Wet above 200.
- Air-quality monitoring. Temperature, humidity, carbon dioxide, PM2.5, PM10, formaldehyde and TVOC, taken room by room with the unit closed, as found.
- Olfactory and visual survey. Where the odour is strongest is usually where the growth is.
- Reference standards. DOSH ICOP IAQ 2010 and the DOSH mould remediation guidelines of 2019, for context.
Indoor air quality
The air, measured room by room.
Indicative readings taken with the unit closed, as found. PM2.5 and PM10 in µg/m³; formaldehyde (HCHO) and TVOC in mg/m³.
| Room | Temp °C | RH % | CO₂ ppm | PM2.5 | PM10 | HCHO | TVOC | AQI |
|---|---|---|---|---|---|---|---|---|
| Kitchen | 31 | 63 | 1145 | 49 | 71 | 0.040 | 0.06 | 67 |
| Living room | 28 | 67 | 1008 | 46 | 65 | 0.015 | 0.29 | 63 |
| Master bedroom | 30 | 62 | 993 | 50 | 74 | 0.045 | 0.05 | 68 |
| Office / study | 27 | 54 | 906 | 44 | 61 | 0.013 | 0.06 | 61 |
Humidity on the high side. Relative humidity sits in the low-to-mid 60s in the kitchen, living room and master bedroom. For Malaysia that is a little above comfortable, and it is a condition that favours mould. The study reads a healthier 54%.
Carbon dioxide, mildly elevated. Roughly 900 to 1150 ppm reflects a closed, sealed unit at the time of inspection, highest in the kitchen. Gentle ventilation resolves this.
Dust particulates, raised. PM2.5 and PM10 read above guideline in every room, highest in the kitchen and master bedroom. Settled dust carries microbes; an air purifier and regular dusting bring these down.
Formaldehyde and TVOC, low. Both within comfortable levels throughout, consistent with ordinary furnishings. No chemical air-quality concern.
The core
The heart of the problem is the kitchen.
On entry the unit carried a noticeable musty odour, strongest in the kitchen. The strongest of all was drawn from behind the kitchen cabinet, above the oven, where the concrete slab meets the cabinet ceiling. This is exactly the area that had been scraped, patched and repainted a month earlier.
In our professional opinion, a surface repair of this kind does not resolve mould that has established within the concrete slab. The growth sits inside the porous concrete and behind the panels; scraping and repainting removes what is seen while the growth beneath remains. Under ultraviolet light and by the strength of the odour, that hidden growth appeared to be still present and active.
Why the odour is the tell. A musty smell of this kind is typically associated with MVOCs, gases released by microbial growth. It is strongest at the cabinet because that is where the active, hidden growth sits. A freshly repainted surface with a strong musty odour behind it is the classic signature of a repair that never reached the growth within the slab.
Moisture mapping
The moisture is still active in the slab.
The upstairs source had been arrested, yet the concrete above the kitchen cabinet still held moisture in the Wet band. The Protimeter was walked across the slab in a grid so the footprint could be mapped, not guessed at.
Wettest point~1000
Along the slab800 · 600 · 460
Tapering354 · 287 · 239
Dry boundary166
A moisture footprint, not a single spot. Readings run from about 1000 (Wet) at the worst point, stepping down through 800, 600, 460, 354, 287, 239 and 220, to about 166 where the slab becomes dry. Together they map the true extent of the retained moisture across the cabinet area.
Wet means the moisture is still there. On this 0 to 1000 scale, anything above 200 is Wet. Values near 1000 mean the concrete is still carrying significant moisture roughly a month after the surface repair. The slab has not dried.
No active inflow, but a slow dry. Thermal imaging found no active leak, so this is retained moisture rather than a running one. Because it sits within the concrete it dries very slowly on its own, and needs assisted drying as part of remediation.
Why it matters. Retained moisture will continue to feed mould until the slab is properly dried and treated. This is the reason the odour returned after the repaint, and why it will return after the next one.
Hidden mould
Revealed under ultraviolet.
Under 365nm ultraviolet light, residue that is invisible in daylight fluoresces. Across the ceilings, the painted walls, the doors and switches and inside the wardrobes, the brighter patches are residue consistent with mould or microbial matter. Away from the kitchen this reflects long-standing, low-level growth typical of a thirty-year-old building: at an acceptable, controllable level, but real.
Why it is happening
More than one cause, honestly set out.
An inspection is only useful if it is straight with the client. The comfortable story was “the upstairs leak did this”. The evidence said something more layered, and we make no finding of fault against any party.
- The house factors are the larger part. A thirty-year-old structure, relative humidity in the 60s, and melamine and plywood cabinetry that feeds mould. On these factors alone, growth of this kind is common in this climate.
- The upstairs moisture was a catalyst. The leak from the unit above added moisture that accelerated the growth, particularly in the kitchen slab directly below the source. A smaller share of the cause, but a real one.
- The surface repair did not treat the core. Removing the visible mould and repainting improved the appearance but left the growth within the slab. This is why the musty odour returned and remains: the core was never addressed, and the retained moisture continues to feed it.
In one line. The mould is mostly a house-and-humidity condition that the upstairs leak accelerated; the recent surface repair covered it without treating the core, which is why it is still active and still smells.
Materials and the rest of the home
What is affected, and what is sound.
Not everything in the home is a concern. The inspection separated the materials holding growth from those performing well, so that any works are targeted and not wasteful.
| Element | Verdict | What we found |
|---|---|---|
| Kitchen cabinetry | Affected | Melamine and plywood, materials that hold moisture and are a ready food for mould. Under ultraviolet the cabinet backs and interior show residue consistent with mould. Should be removed as part of proper remediation, and replaced with a solid or anti-mould material, or left open so the wall can breathe. |
| Solid-wood wardrobe | Sound | Sixteen years old and showing no meaningful growth. Solid timber is one of the better materials for this climate, and it demonstrates that the issue is material and moisture driven, not simply age. |
| Flooring and contents | Acceptable | SPC and vinyl flooring edges and the stored contents read at an acceptable level; any residue at the edges is minor and can be treated in place. Not a driver of the problem. |
| Air-conditioning | Worth attention | Mould spores settle within an air-conditioner’s coil. The affected unit should be treated or serviced so it does not recirculate spores after remediation. |
Health considerations
Living with hidden mould.
The following is general, evidence-based information from recognised authorities. It is not medical advice and not a diagnosis; for any personal health concern, please consult a medical doctor.
What the authorities conclude
The World Health Organization (2009), the US Institute of Medicine (2004), the US EPA and the US CDC conclude that occupants of damp or mould-affected indoor spaces are at increased risk of respiratory symptoms such as cough, wheeze and nasal and throat irritation, of asthma exacerbation, and of allergic and inflammatory responses. MVOCs are a recognised cause of the musty odour and of irritation at higher exposures.
WHO Guidelines for Indoor Air Quality: Dampness and Mould (2009) · US IOM, Damp Indoor Spaces and Health (2004) · US EPA, Mold and Health · US CDC, About Mold · Malaysia DOSH ICOP IAQ 2010 · DOSH Guidelines on Control of Molds Contamination and Remediation (2019)Everyday effects. Musty odour, and for sensitive individuals, headaches, nasal or throat irritation and a stuffy feeling in the space. One occupant present noted a personal sensitivity that reacts to mould; that is a matter for their doctor.
The dust reading matters too. The raised PM2.5 and PM10 are worth reducing with an air purifier, as fine dust carries microbes and can aggravate the same symptoms.
Do not disturb it in the meantime. Scraping, sanding or dry-wiping the affected areas releases spores into the air. Until proper remediation, the advice was to leave the kitchen area alone and not to scrape or spray it.
What this means here. It supports treating the source properly rather than masking it, and reducing the dust load. It is not a statement about anyone’s individual health.
The verdict
Treat the core properly. Protect the rest.
The recommendation was a targeted programme, not an expensive whole-house cosmetic job. A thorough core treatment where the problem is real: the kitchen cabinet removed, the slab and walls opened by soft grinding, dried with machines, then built back with primer, biocide, antimicrobial and antifungal coatings and a low-moisture antifungal paint, under a five-year workmanship warranty. Elsewhere, a lighter protective treatment so growth does not re-emerge under ultraviolet. Stage-based over roughly two months, with the home’s contents covered and protected. A further surface-level repair would simply return to the same state.
Where the evidence stands
What the inspection showed.
LeakArrested. Thermal imaging found no active water ingress anywhere in the unit.
MoistureStill active in the kitchen slab: a mapped footprint from about 1000 (Wet) at the worst point down to 166 at the dry boundary, a month after the surface repair.
Hidden growthResidue consistent with mould under ultraviolet across the kitchen cabinet area, and at a low, controllable level on ceilings, switches and inside wardrobes elsewhere.
AirHumidity in the 60s, carbon dioxide mildly elevated in a closed unit, particulates raised, formaldehyde and TVOC low.
CauseMostly house and humidity, accelerated by the upstairs moisture, and concealed rather than cured by the repaint. No finding of fault against any party.
NextSpecies identification, if wanted, by accredited laboratory swab at the remediation stage through our university research partner. See how that looks in A Wellness Home in Kuala Lumpur.
On privacy. The client’s name has been changed and the building, unit and street have been withheld to protect the family’s privacy. Every reading, photograph, finding and recommendation on this page is from the actual inspection carried out in Kuala Lumpur on 19 September 2026, unaltered. Faces have been cropped from working photographs.
All ultraviolet, thermal and air-monitor observations are indicative and taken at a single point in time. They indicate conditions; they are not a laboratory certification, and no organism or species is named. Species identification requires accredited laboratory analysis, which Cleanaholics arranges through its university research collaboration. This record is a professional environmental and hygiene assessment; it is not medical advice, not a legal determination, and makes no finding of fault against any party.
- Choosing a selection results in a full page refresh.