Mould testing in rented homes: what it involves and whether you need it

If you have mould in your rented home, you may wonder whether having it tested is useful, and whether it will help with a complaint or legal claim. Below, we look at what mould testing involves, when it might be useful, and when it is not necessary.

Key facts

• The 2024 to 2025 English Housing Survey found about 5% of homes in England, around 1.4 million, had a problem with damp, most common in privately rented homes (10%). English Housing Survey 2024-25, GOV.UK
• Official guidance from the UK Health Security Agency and the Department of Health and Social Care links damp and mould in homes in England to around 5,000 cases of asthma and 8,500 lower respiratory infections among children and adults. Health risks of damp and mould, GOV.UK

What is mould testing?

Mould testing involves taking samples from the mould growth in a property and sending them to a laboratory to identify the type of mould present and, sometimes, the level of mould spores in the air.

There are two main types:

Surface sampling: A swab or tape lift is taken from the surface where mould is visible. This identifies the species of mould present.

Air sampling: Air is drawn through a cassette or collected on a plate to measure the concentration of mould spores in the air. This is used to assess whether levels are elevated compared to outside air.

Is mould testing needed to make a disrepair claim?

In most cases, no. For a standard housing disrepair claim involving damp and mould, you do not need laboratory mould testing. What matters legally is:

• Evidence that mould and damp existed (photographs, your account, inspection reports)
• Evidence that the cause was a landlord's repair failure (structural damp, a failed damp-proof course, a leaking roof)
• Evidence that the landlord was told and failed to act

A surveyor's report, which a housing disrepair solicitor will arrange as part of the claim, is usually sufficient to establish the cause and extent of the damp and mould without laboratory testing.

When might mould testing be useful?

There are some situations where mould testing may add value:

Health impact evidence: If you are claiming personal injury as part of a disrepair claim, for example, because a family member has developed asthma or a respiratory condition, air sampling results showing elevated mould spore concentrations can support the connection between the mould and the health effects. However, a medical report linking the symptoms to the conditions is usually more important than the mould test itself.

Identifying the species: Most mould found in homes (including black mould) is common and well understood. In unusual cases where a rare or particularly harmful species is suspected, testing can confirm what is present.

Disputes about cause: If a landlord is claiming that the mould is caused entirely by lifestyle (condensation) rather than structural issues, and there is a genuine factual dispute, a surveyor's assessment is usually more persuasive than a mould test, but in complex cases, testing may be additional evidence.

Should I arrange mould testing myself?

It is usually not necessary to arrange mould testing before contacting a housing disrepair solicitor. Solicitors and surveyors working on disrepair claims have established processes for gathering evidence, and adding privately commissioned mould tests may not improve your case.

If you are interested in whether mould is affecting your health, speak to your doctor (or general practitioner) first, they can assess symptoms and refer for specialist investigation if needed.

What evidence should I collect instead?

The most useful evidence for a damp and mould disrepair claim is:

1. Photographs, taken regularly, with dates. Photograph every area affected, including the worst areas.
2. Written reports to your landlord, emails and texts showing when you reported the problem.
3. The landlord's response (or lack of response)
4. Medical records if health has been affected
5. Records of damaged belongings, photographs and receipts if mould has damaged clothing, furniture, or bedding

This evidence, combined with an independent surveyor's report, is the foundation of a disrepair claim.

When should I contact Support for Tenants?

If your rented home has damp and mould that your landlord has failed to deal with, you may have a housing disrepair claim.

Call us on 0800 030 4669. No upfront cost. You only pay if you win, and the fee comes out of the compensation, not your pocket. If you don't win, you pay nothing.

Sources

• Section 11, Landlord and Tenant Act 1985 (legislation.gov.uk)
• Homes (Fitness for Human Habitation) Act 2018 (legislation.gov.uk)