What should you do about mould in a rented property?

In England, treat mould in a rented home as a housing-condition and health issue, not as a cleaning argument. The practical sequence is: record it, investigate the cause, fix the source, ventilate correctly, and follow up long enough to know it has not returned.

What should you do about mould in a rented property?

You should report or record mould immediately, photograph it, investigate the damp source, and arrange repairs or remediation because an English private landlord must keep the dwelling fit for human habitation throughout the tenancy: “there is implied a covenant by the lessor that the dwelling—(a)is fit for human habitation at the time the lease is granted... and (b)will remain fit for human habitation during the term of the lease.”

Damp and mould growth is now hazard 11 in the 21-hazard HHSRS list, not “one of 29” as older pages still say: “Physiological requirements 9. Excess cold 10. Radiation 11. Damp and mould growth.” Do not default to blaming “lifestyle choices”; government guidance says, “We are absolutely clear that it is totally unreasonable to blame damp and mould in the home on 'lifestyle choices'.”

For Scotland and Glasgow searches, the equivalent route is the Repairing Standard, not England’s s.9A regime. Abodient can hold the tenant report, photographs and contractor documents against the property so the chronology is not lost if black mould becomes a dispute.

What causes condensation in a rental property, and how do you stop it?

Condensation in a rental property is caused when everyday moisture from people, washing, cooking and bathing meets cold surfaces or inadequate ventilation, and you stop it by keeping humidity in the 40–60% band, preventing persistent 70% relative humidity, heating consistently, and using adequate extraction.

HHSRS guidance says, “Occupiers produce up to a kilo of water vapour a day, mainly through perspiration and breathing, bathing, cleaning, cooking and drying of laundry.” The mould-risk threshold is higher and more precise than the usual blog figure: “Moulds can grow where the indoor relative humidity persistently exceeds 70%.” The target is also stated plainly: “Indoor relative humidity should be between 40% and 60% except for short periods where it will fluctuate due to factors such as bathing and cooking.”

For mechanical extract, Approved Document F gives 30 l/s for a kitchen cooker hood extracting outside, 60 l/s without one, 15 l/s for a bathroom and 6 l/s for sanitary accommodation: “Kitchen (cooker hood extracting to the outside) 30 / Kitchen (no cooker hood or cooker hood does not extract to the outside) 60 / Utility room 30 / Bathroom 15 / Sanitary accommodation 6.”

Is there a tool you can use to check for damp or mould, and what does it cost?

You can use a moisture meter, hygrometer or professional damp survey to check damp or mould, but no English private-rented rule requires a landlord to buy a specific meter; even Awaab’s Law defines competence by the landlord’s reasonable opinion of skill and experience, not by owning a device: “"competent investigator" means a person that, in the reasonable opinion of the lessor, has the skills and experience necessary to determine whether a social home is affected by a significant hazard or emergency hazard”.

At the cheap end, a DIY damp meter is about £20: “Magnusson Moisture Meter (594YC) £19.97 Inc Vat.” A surveyor-grade Protimeter Surveymaster BLE is about £560: “Price: £559.80 inc VAT (£466.50 ex VAT).” A basic damp survey is commonly £150–£250: “A Basic Damp Survey involves a general visual inspection with tools like moisture metres, which typically costs between £150 and £250.” A cheap meter is useful for spotting patterns, but a legal dispute usually turns on diagnosis and repair history rather than one isolated reading.

Is there a tool to measure air quality, and what does it cost?

You can measure air quality and mould risk with temperature, humidity and CO2 sensors, but the only air-measuring device English rented-home law specifically requires is a carbon monoxide alarm where a fixed combustion appliance is present: “a carbon monoxide alarm is equipped in any room of the premises which is used wholly or partly as living accommodation and contains a fixed combustion appliance other than a gas cooker.”

The penalty for breaching that CO-alarm duty is capped at £5,000, not £7,000: “The amount of the penalty charge must not exceed £5,000.” Humidity and air-quality monitors are optional aids; government guidance says, “Smart sensors may be a useful aid to monitor temperature, humidity and indoor air quality.” For mould risk, the useful readings are persistent 70% RH and the 40–60% target band: “Moulds can grow where the indoor relative humidity persistently exceeds 70%,” and “Indoor relative humidity should be between 40% and 60% except for short periods where it will fluctuate due to factors such as bathing and cooking.”

Aico’s price list shows hardware with software at £149.36 for a temperature/humidity sensor, £195.30 for one adding CO2, and £281.91 for a gateway: “Hardware with software included £281.91 £149.36 £195.30.”

Why does water keep coming into a rental property even after fixing the guttering and roof?

Water can keep coming into a rental property after roof and gutter works because damp often has more than one source, so repairing a roof leak may leave condensation, ventilation failure, penetrating damp elsewhere, or bridging still active.

Gutters are expressly part of the landlord’s repair duty: “to keep in repair the structure and exterior of the dwelling-house (including drains, gutters and external pipes).” But HHSRS guidance gives the reason a single repair often fails: “The cause(s) of damp can sometimes be difficult to determine and may have more than one source.” The national data backs that up: “The most common form of damp was severe condensation (3%), which was more prevalent than rising damp (1%) or penetrating damp (2%).”

Ventilation is the obvious next check because “1% of dwellings had inadequate ventilation, of which 60% had a problem with damp.” Older trade pages still quoting 839,000 damp homes are stale; the 2024–25 English Housing Survey says there were 1.4 million dwellings, or 5%, with damp, and the private rented sector was worst at 10%.

What should you do if mould keeps coming back despite professional remediation?

If mould keeps coming back despite professional remediation, do not rely on private-sector Awaab’s Law deadlines: no Awaab’s Law timescale yet binds a private landlord, the “12 weeks” figure is only the deadline to begin supplementary preventative work in social housing, and damp-and-mould enforcement is not the £7,000 list but can run through a £40,000 improvement-notice penalty.

Awaab’s Law currently says it “applies to almost all social housing occupied under a tenancy and let by a registered provider,” and the 12-week provision says the work must “begins—(a)as soon as reasonably practicable, but (b)before the end of the period of 12 weeks.” Recurrence is the point: government guidance says, “If damp and mould have reappeared, further investigation and intervention should be pursued.”

The better standard is not another clean-down; it is a fresh root-cause investigation, written findings, corrected ventilation or building defects, and scheduled checks. The Ombudsman benchmark is strong: “It would also be good practice for landlords to schedule follow up visits at set periods, for at least a year after works are completed, to satisfy themselves that the problem has not returned.”

Last reviewed August 2026.

Sources

• Landlord and Tenant Act 1985 s.9A — “there is implied a covenant by the lessor that the dwelling—(a)is fit for human habitation at the time the lease is granted... and (b)will remain fit for human habitation during the term of the lease.” Source
• HHSRS Operating Guidance Part 1 — “Physiological requirements 9. Excess cold 10. Radiation 11. Damp and mould growth” Source
• Department for Levelling Up, Housing and Communities damp and mould guidance — “We are absolutely clear that it is totally unreasonable to blame damp and mould in the home on 'lifestyle choices'.” Source
• HHSRS Operating Guidance Part 2 — “Occupiers produce up to a kilo of water vapour a day, mainly through perspiration and breathing, bathing, cleaning, cooking and drying of laundry.” Source
• HHSRS Operating Guidance Part 2 — “Moulds can grow where the indoor relative humidity persistently exceeds 70%.” Source
• HHSRS Operating Guidance Part 2 — “Indoor relative humidity should be between 40% and 60% except for short periods where it will fluctuate due to factors such as bathing and cooking.” Source
• Approved Document F — “Kitchen (cooker hood extracting to the outside) 30 / Kitchen (no cooker hood or cooker hood does not extract to the outside) 60 / Utility room 30 / Bathroom 15 / Sanitary accommodation 6” Source
• Awaab's Law regulations, SI 2025/1042 reg.2 — “"competent investigator" means a person that, in the reasonable opinion of the lessor, has the skills and experience necessary to determine whether a social home is affected by a significant hazard or emergency hazard” Source
• Screwfix Magnusson Moisture Meter — “Magnusson Moisture Meter (594YC) £19.97 Inc Vat” Source
• The Tape Store Protimeter Surveymaster BLE — “Price: £559.80 inc VAT (£466.50 ex VAT)” Source
• MyBuilder damp survey cost guide — “A Basic Damp Survey involves a general visual inspection with tools like moisture metres, which typically costs between £150 and £250.” Source
• Smoke and Carbon Monoxide Alarm (England) Regulations 2015 reg.4 — “a carbon monoxide alarm is equipped in any room of the premises which is used wholly or partly as living accommodation and contains a fixed combustion appliance other than a gas cooker” Source
• Smoke and Carbon Monoxide Alarm (England) Regulations 2015 reg.8 — “The amount of the penalty charge must not exceed £5,000.” Source
• Department for Levelling Up, Housing and Communities damp and mould guidance — “Smart sensors may be a useful aid to monitor temperature, humidity and indoor air quality” Source
• Aico HomeLINK pricing — “Hardware with software included £281.91 £149.36 £195.30” Source
• Landlord and Tenant Act 1985 s.11 — “to keep in repair the structure and exterior of the dwelling-house (including drains, gutters and external pipes)” Source
• HHSRS Operating Guidance Part 2 — “The cause(s) of damp can sometimes be difficult to determine and may have more than one source.” Source
• English Housing Survey 2024 to 2025 headline report — “The most common form of damp was severe condensation (3%), which was more prevalent than rising damp (1%) or penetrating damp (2%).” Source
• English Housing Survey 2024 to 2025 headline report — “1% of dwellings had inadequate ventilation, of which 60% had a problem with damp.” Source
• Awaab's Law guidance for social landlords — “Awaab's Law applies to almost all social housing occupied under a tenancy and let by a registered provider.” Source
• Awaab's Law regulations, SI 2025/1042 reg.13 — “the lessor must secure that the relevant supplementary preventative work begins—(a)as soon as reasonably practicable, but (b)before the end of the period of 12 weeks” Source
• Housing Act 2004 s.249A — “The amount of a financial penalty imposed under this section is to be determined by the local housing authority, but must not be more than £40,000.” Source
• Department for Levelling Up, Housing and Communities damp and mould guidance — “If damp and mould have reappeared, further investigation and intervention should be pursued” Source
• Housing Ombudsman Spotlight report on damp and mould — “It would also be good practice for landlords to schedule follow up visits at set periods, for at least a year after works are completed, to satisfy themselves that the problem has not returned.” Source