Ellen Rashbrook’s home was so badly ridden with mould that water would run down the walls of the the bedrooms where she and her two young sons slept.

When she tried to complain about the flat in Henry Jackson House, a council-owned mansion block in southwest London’s affluent Putney, Wandsworth Council told her to open the windows more.

“They were telling me that it was an issue with lifestyle,” Rashbrook, a charity fundraiser and former council officer, said.

Spots of mould began appearing in her home in 2013, two years after she had moved in with her sons, then aged 10 and 15. Then she started to get sick.

But it was not just the breathing problems you might expect in a mouldy home. Rashbrook began to suffer from skin complaints, itchiness, rashes and brain fog.  

In 2017, leaks in her bathroom soaked the wooden flooring beneath her tiles, leading them to rot away. Repeated complaints to the council resulted in a partial solution – cleaning away the visual mould and laying a new floor on top of the old one.

By now, Rashbrook’s health conditions were so serious that she was under the care of doctors from rheumatology, dermatology, neurosurgery and two different respiratory teams.

In June 2024, one of her doctors at Barts Health Trust wrote that the mould in her flat was “highly likely” to be a major factor in her poor health.

“The danger of mould to our health, both to skin and immune systems, is well evidenced and she is especially vulnerable,” the doctor said.

Now 50, over a decade since she first noticed the mould in her home, Rashbrook is in a legal dispute with the council – whose expert witness insists that only minor work is required to treat the problem.

An expert appointed by Rashbrook’s lawyers disagrees, and the two parties will meet in court next year, where the council is seeking an injunction to force her to carry out the minor works they believe necessary, without providing her with alternative accommodation.

Rashbrook is challenging this. “It’s exhausting,” she said.

A spokesperson for Wandsworth Council said it would be inappropriate to comment on Rashbrook’s case as a result of the ongoing legal action, but the council said: “We take the wellbeing of our residents very seriously.”

‘Quick fix’ solutions aren’t working – and it’s putting renters at risk

Rashbrook’s dispute with her council underlines two things which experts and campaigners have been saying about the extensive problems with household damp and mould in the UK for some time. 

First, the quick fix solutions landlords tend to reach for are often ineffective – and sometimes dangerous – and firms that carry out the fixes are cashing in, in a practice dubbed the “mould rush” by one industry expert.

Second, exposure to mould can cause a much wider, deeper range of health issues than we might normally expect.  

Air particle surveys in Rashbrook’s flat found a range of mycotoxins – the toxic, airborne chemical compounds which are released by mould.

Anyone who lives in a mouldy home will breathe these in without knowing it: some of the particles in the Putney flat were as small as 0.3 microns. To put this in context, a single strand of human hair is about 70 microns thick.

These toxic particles slip past the hairs in your nose and throat and settle right at the bottom of your lungs. From there, they can cause very serious – and not fully understood – damage to health.  

And the cost is being felt by everyone. The NHS spends an estimated £1.4bn per year on treating illnesses linked to damp, cold, and mouldy housing, according to analysis by the Building Research Establishment.

The most recent English Housing Survey estimated that 1.4 million dwellings had a damp problem – the majority of them rented housing. There were 142,000 where it is considered a Category 1 hazard, the most severe.  

Renters are disproportionately at risk. Damp affects 10 per cent of privately rented homes, and 7 per cent of socially rented homes –

but just 4 per cent of owner occupied homes.

If you are a tenant, you are much more likely to be inhaling these tiny, toxic particles that can cause serious damage to health.  

Lisa Malyon, the founder of the UK Centre for Mould Safety, described it as “an avoidable national health crisis that is costing the UK billions in physical and mental health illness”.

Renters are paying more than ever before for the homes making them ill

In the private rented sector in particular, rents have risen rapidly this decade.

Average rents have increased 35.8 per cent since January 2020, to an average of £1,387 per month. In London, a two-bedroom home costs on average £2,232 a month to rent, up from £1,643 a decade ago. Tenants are paying more than ever, but the mould is getting worse, and so will their health as a result.  

Malyon, who started campaigning on the issue after she was hospitalised due to mould exposure, said: “Most people think [mould] is a surface issue but it’s not – it’s affecting the indoor air we breathe. I see, all day every day, the harm it does to people’s health. The symptoms are really broad.”

Cowboy cleaning firms ‘jumping on mould rush’

Industry experts warn that recent legal changes aimed at increasing protections for renters will not necessarily fix the problem.

In October last year, the social housing sector became subject to ‘Awaab’s Law’ – named after two-year-old Awaab Ishak who died from exposure to serious damp in his family’s home in 2020. The same provisions will be introduced into private rented homes, likely in 2027, as a result of the Renters’ Rights Act.  

This requires landlords to investigate reports of damp and mould within 10 days and fix it within a further five.

This is good on paper – but in the real world it is pushing landlords towards temporary solutions offered by cleaning companies set up to profit from the massive increase in work. The result is often a cosmetic clean that doesn’t address the underlying problem or help fix the air quality.  

Carl Reid, a damp and mould surveyor with Swift Maintenance Solutions, said: “Awaab’s Law has had a completely negative effect on parts of the industry.

“Cleaners, decorators and even roofers are presenting themselves as damp and mould experts. Everybody has jumped on the ‘mould rush’, and tenants are suffering.” 

These companies often simply wash the mould off with biocides and paint the walls. But even if the walls look clean, the air will still be filled with mycotoxins.  

Difficulty getting diagnosed

The exact impacts of mould on human health are not completely settled as a matter of medical science. In the US, Chronic Inflammatory Response Syndrome is a recognised medical outcome from mould exposure – with 13 different types of symptom included in its definition. But with such a broad range of potential symptoms, it is hard to diagnose precisely.  

Dr Catrin Moore, a reader in global health and infectious diseases at City St George’s and a member of the World Health Organisation’s advisory group on antimicrobials, said more research is required.  

She herself suffered a long-period of poor health with a wide range of different symptoms which no doctor could properly diagnose, before discovering a leak above her bedroom had caused damp and mould in her roof. When she moved out of the home, the symptoms immediately improved.  

“Medical science doesn’t know how to respond to this, because there are too many different symptoms that fall under the umbrella,” she said. “I get breathless, I get pins and needles, I get brain fog, I get lots of different things. But then other people get something similar, but not quite the same from mould exposure. And so doctors don’t really know which bucket to put that into.” 

The WHO recognises poor indoor air quality as “an important risk factor to human health” – due to the “hundreds of species of bacteria and fungi that grow indoors when sufficient moisture is available”.  

But the mould in our homes is often treated instead as a cosmetic problem which can be cleaned away – not a major risk to health which is mostly unseen in the air.