Buying Guide
Mould in My Flat — What Should I Do? UK Guide
Updated July 2026
Mould in a UK flat is incredibly common — and incredibly frustrating. Whether you own or rent, this guide tells you exactly what to do: how to remove it safely, which products prevent it coming back, and if you're renting, what your landlord is legally required to do about it.
Quick answer
Our top pick: HG Mould Spray 500ml
£6 on Amazon
Step 1: Don't panic. Step 2: Photograph everything. Step 3: Kill the mould with specialist spray (£6). Step 4: Measure your humidity (£10). Step 5: If above 60% RH, get a dehumidifier (£85+). Step 6: If renting, report to your landlord in writing.
Check Price on Amazon →Is mould in a flat dangerous?
Mould releases spores that trigger asthma, allergies, and respiratory infections. Black mould (Stachybotrys) is the most harmful of the common species. The NHS recommends removing visible mould promptly, and treating the underlying moisture source at the same time.
Children, elderly people and anyone with existing respiratory conditions are most at risk. If mould covers more than one square metre or you can smell it without seeing it, treat it as urgent.
How to remove mould from a flat — step by step
- Ventilate — open windows before you start.
- Protect yourself — put on rubber gloves and an FFP2 mask.
- Spray with HG Mould Spray £6 — Amazon →
- Wait 10 minutes, then wipe clean with a damp cloth.
- For mouldy silicone: replace with UniBond Anti-Mould Sealant £5–8 — Amazon →
- Prevent regrowth: add Owatrol VC175 Additive £8–12 to paint — Amazon →
Products to prevent mould coming back
HG Mould Spray 500ml
The UK's best-selling mould remover — spray, wait 10 minutes, wipe.
Pros
- Kills mould on contact
- No scrubbing needed
- Works on grout, paint, silicone
Cons
- Strong bleach smell — ventilate
Who it's for: Removing visible mould in bathrooms, bedrooms and kitchens
Check Price on Amazon UK →ThermoPro TP50 Hygrometer
Cheapest way to know if humidity is above the 60% RH mould threshold.
Pros
- Instant humidity reading
- Battery-powered
- Under £10
Cons
- Basic display
Who it's for: Diagnosing whether your flat's humidity is above the 60% RH mould threshold
Check Price on Amazon UK →Devola 12L Dehumidifier
The best value dehumidifier for a mouldy UK flat.
Pros
- Which? Best Buy tier price
- Built-in humidistat
- Covers most flats
Cons
- Louder than premium models
Who it's for: Getting a mouldy flat back below 60% RH within days
Check Price on Amazon UK →ANSIO Wardrobe Bags
Hangs inside wardrobes to keep clothes dry and mould-free.
Pros
- No electricity
- Hangs inside wardrobes
- Stops clothes going mouldy
Cons
- Refills needed every 2 months
Who it's for: Protecting clothes and shoes in damp bedrooms
Check Price on Amazon UK →Why does mould grow in UK flats?
- High humidity (above 60% RH)
- Poor ventilation (sealed windows, no extractor)
- Cold surfaces (external walls, single glazing)
- Indoor moisture (cooking, showering, drying clothes)
How to prevent mould coming back
Measure humidity daily, keep it between 40–60% RH, ventilate the kitchen and bathroom while cooking or showering, and never dry laundry in a sealed room without a dehumidifier running. Best dehumidifiers guide →
Mould in a flat you own
Check for structural issues — rising damp, penetrating damp from a shared wall, or a leaky flat above. If mould keeps returning in the same spot, the cause is almost always structural rather than lifestyle.
Improve ventilation. A modern humidity-sensing bathroom extractor fan is a permanent fix worth investing in. Use the prevention products above for daily management. Best bathroom extractor fans →
Mould in a rented flat — your rights
Warning
Landlord must investigate within 14 days (Awaab's Law)
They cannot blame lifestyle without investigating
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