MOULD REMOVAL
Mould at Home? We Find the Source Before We Quote
Quick answer
Averta's mould removal service starts with a check for the moisture or leak source — we don't apply treatment to the surface before we understand why mould is growing there in the first place. EPD's guidance is clear: mould may cause allergic reactions in mould-sensitised individuals, and there's currently no way to establish a "safe" mould threshold, so the recommendation is to remove all visible mould regardless of extent. We quote by unit area and mould severity (light/moderate/severe), starting from HK$700 (preventive coating), HK$1,400 (removal), and HK$2,100 (removal plus prevention); the coating warranty runs 6-12 months, with a free re-treat if mould recurs at the same spot within the warranty period.
How we work
- Moisture/leak source check. Before we remove anything, we look at why that spot is growing mould — poor bathroom ventilation? Condensation pooling under an air-conditioner? A leak coming down from the unit above? Without finding the source, mould usually comes straight back after removal. This step is included in the quote assessment at no extra charge.
- Scope assessment and quote. We assess the affected area and severity on-site (or from a WhatsApp photo) and give a transparent quote — never an "all-in lump sum" with no breakdown.
- Mould removal. We use a method suited to the surface — wall, ceiling, bathroom tile, furniture — to thoroughly remove all visible mould.
- Preventive coating (optional add-on). A protective coating applied after removal slows recurrence.
- Humidity management advice. We leave you with practical steps — dehumidifying, ventilation, drying out water-damaged spots — to reduce the chance of mould returning at the source.
Mould and health: what EPD actually says
Hong Kong's Environmental Protection Department, through its Indoor Air Quality Information Centre, is the authoritative government source on indoor mould locally. A summary of their guidance:
- Inhaling mould spores or touching mould patches may cause allergic reactions in mould-sensitised individuals; other than allergic/irritant reactions, other symptoms are not common.
- There is currently no way to establish a safe threshold for mould's health effects — so regardless of how much mould is present, the recommendation is to remove all visible mould.
- Prevention: keep indoor relative humidity below 70%; dry water-damaged areas within 24-48 hours.
- EPD does not recommend using pesticides or disinfectants for DIY mould cleanup (a potential toxicity risk to whoever does the cleaning) and recommends engaging a suitable or competent person for removal.
- For commercial/office premises: since July 2019, "mould" has been one of the parameters under EPD's Indoor Air Quality Certification Scheme.
This is the basis for everything on this page — no alarmist framing, and no citation of anything unrelated to indoor mould.
Pricing: published "from" bands, no lump-sum sleight of hand
The three tiers below are anchored on the market's published tier structure (few operators publish real service prices; we price against that public structure):
| Tier | From | Includes |
|---|---|---|
| Long-lasting preventive coating | HK$700 | Surface cleaning + preventive coating application |
| Mould removal | HK$1,400 | Thorough removal of all visible mould |
| Removal + prevention (full package) | HK$2,100 | Removal + preventive coating |
The actual quote depends on two factors:
- Unit area — a larger affected area means more labour and materials.
- Severity (light/moderate/severe) — surface mould spotting is a different job from mould that's penetrated the wall or caused paint to peel.
The coating warranty runs 6-12 months, with a free re-treat if mould recurs at the same spot within the warranty period. This matches the strongest warranty terms currently offered in the market.
When mould risk peaks: 回南天 and the wet season
Hong Kong's Observatory explains "回南天" (huínántiān) as what happens when the winter monsoon weakens and warm, moist southerly marine air meets surfaces — walls, floors — that haven't warmed up yet, causing condensation to form on them, typically during the winter-to-spring transition. This is one driver of Hong Kong's spring damp-and-mould problem, and it extends into a longer wet-season window of elevated humidity. For live and seasonal humidity data, see our Hong Kong Humidity Tracker.
Not sure if you need mould removal? WhatsApp us a photo and we'll help you find the source first
Frequently asked questions
Mould at home — who's responsible for dealing with it or paying for it, the tenant or the landlord?
It depends on the cause — ordinary humidity-driven wear and tear, tenant negligence, or a structural leak each point to a different party, and Averta doesn't provide legal advice. We've put together an independent guide covering the three common scenarios and how a professional assessment report can help establish the facts: Who's Responsible for Mould in a Hong Kong Rental?
Can I just buy a mould spray and do it myself?
For light surface spotting — a small patch on bathroom tiles, say — DIY cleaning plus better ventilation is usually enough. But for larger areas, recurring mould, or anything involving peeling paint or a ceiling leak, we'd recommend a professional: EPD itself doesn't recommend DIY pesticide or disinfectant use for cleanup, and recurring mould usually means the underlying moisture or leak source hasn't been resolved — spray alone treats the symptom, not the cause.
The mould came back after you removed it — did you do a bad job?
Removal itself isn't the hard part; whether the source has been resolved is. If the moisture source (ventilation, a leak) hasn't been addressed, mould can recur after anyone's removal work — which is why we insist on a source check before quoting. Our coating warranty runs 6-12 months with a free re-treat at the same spot within that period; but if the underlying cause hasn't been fixed (an ongoing leak from upstairs, for example), we flag that clearly at the assessment stage rather than folding it into the warranty as if it were covered. Where a structural leak is suspected, the case can also be pursued formally through the FEHD/Buildings Department joint mechanism via the 1823 hotline.