Tackling Damp and Mould: Key Takeaways from our Expert Q&A

Did you know that opening windows, even when it’s freezing cold outside, can actually make it easier to heat your home, and importantly, keep it mould free? Neither did we, until we hosted an Expert Q&A event about tackling damp and mould.

Answering pre-submitted questions from over 120 attendees, Dr Sirid Bonderup (Aalborg University), Jan Gilbertson (Centre for Regional Economic and Social Research, Sheffield Hallam University), Valentina Marincioni (UK Centre for Moisture in Buildings, and University College London), and Rachel Harris (University of Sheffield) discussed and shared their expertise on the causes and consequences of, and solutions to, the prevalent damp and mould issue experienced by many in the UK now.

As millions of households already living in fuel poverty are still struggling through the ongoing cold weather, we share here the key lessons to emerge from the discussion in the hope it helps those experiencing damp and mould, and those working on the frontline to combat the issue. A link to the event recording and additional resources can be found at the end.

Mold in the corner of the white ceiling and yellow wall, with white heat pipe.

What is mould? Where does it come from? 

  • Mould is part of the fungi family with spores everywhere! 
  • Our homes are the perfect environment for mould growth – they have relatively high humidity, temperatures between 5-35*, and organic material for food e.g., wallpaper, textiles, or just the normal thin layer of dust & grease we all produce
  • The root cause of mould growth is always damp. And what causes damp? Usually, it’s a mix of defective buildings (e.g., rising damp, leaky pipes) and less than optimal inhabitant behaviour (e.g. not drying surfaces after bathing or washing up, not ventilating sufficiently)
  • Identifying mould is usually quite easy as you can see it and it has a distinctive smell. But identifying WHY there is damp, and the source of the damp, is much harder and most often requires the help of a professional
  • Black mould tends to get more attention as the most dangerous type but that is not necessarily always the case. There is also white mould, pink mould, and green mould. Importantly, all types are allergens
  • Mould should be dealt with straight away. Small patches on surfaces designed to withstand moisture e.g., bathroom/kitchen tiles or grouting, can be easily cleaned (and dried thoroughly). But mould spots on surfaces not designed for moisture need more serious attention and help
  • Below is a photo of a child’s bed (with recently changed bedding) from some of our recent research. It is a sad but great example of where mould definitely should NOT be growing, and where professional help is needed. Help should also be sought for any patches larger than 2 hands.
A mouldy child’s bed. The bedding had been changed very recently.

What are the physical and mental health implications of living with mould?

  • The main message is clear – mould is not good for anyone
  • We all know that babies & children are at high risk, but there are other groups we should not forget as well – elderly, pregnant, those with sensitivities to allergens such as eczema and asthma, those with weakened immunity such as when receiving chemotherapy etc.
  • Our health has “dose-response” relationships to mould. The amount of mould we are exposed to, how close the mould is to us and how long we are exposed to it, all affects whether and how sick we get. Critically, if exposed for long enough, many will develop chronic issues
  • Most people are aware of mould making asthma worse for all asthma sufferers, but health evidence has now shown a causal relationship for children between mould exposure and asthma. In other words, long term exposure in children can CAUSE asthma
  • What about mould and mental health? Evidence suggests an association between mould and depression. We also know the stress of having to deal with mould and the chronic ill health that can come with living with mould can both exacerbate depression
  • Interestingly, there is now some evidence around mould toxicity. Toxins from mould are building up in our bodies and are likely causing issues such as insomnia, brain fog, anxiety & depression. More evidence is needed however about whether this is a causal pathway
  • Fuel poverty is exacerbating many of these issues. Reducing energy bills and a social tariff might go some way to helping, but we really need better retrofit policies to tackle the problem of non-decent homes – Good Home Inquiry found ±4 million homes in Britain to be non-decent
  • There is now evidence that shows upgrading homes and bringing them up to national decent standard does have an effect on hospitalisations for respiratory and cardiovascular diseases. Policy needs to see housing as a key part of health prevention.

What can local authorities do to prevent and reduce the issue? What are the roles and responsibilities of landlords and tenants?

  • Local authorities can do a lot in educating and upskilling themselves and their tenants on retrofit, and a whole house and fabric first approach to improve the standard of existing housing stock
  • There’s courses with the Retrofit Academy that Rachel recommends. She found the Level 5 Diploma in Retrofit Coordination & Risk Management very helpful in giving confidence to fully understand moisture generation, material responses, and risks.
  • An important role for LGAs is to grow both their own & tenants’ understanding of how much water is produced in a household – our breathing, our clothes drying, our cooking etc. & that this moisture needs to get out of the building! Damp is a symptom of a moisture imbalance
  • Landlords in general, whether private, housing associations, or councils need to understand their existing housing stock – where are there issues, how much ventilation do they actually have; what heating systems are in place and that these systems need check ups, cleaning and maintenance, conducted by professionals in order to function properly
  • Asking tenants to vent their homes can only be done if they are supplied with means to vent properly; in a way that’s energy efficient & smart. Use insulated trickle vents, vents that only stop once moisture drops low, and vents not connected to light switches
  • Dehumidifiers on the other hand, are not recommended. They are useful in a catastrophic situation, but should not be used in place of ventilation. They use energy, they do not ventilate, and they can actually be a growth spot for mould
  • Tenants also have a responsibility to report the problem quickly and to stay on top of small patches of mould, especially everyday mould such as in kitchen / bathroom grouting. Managing damp and mould needs to be a collaboration between tenants and landlords, not a conflict
  • It is in everyone’s best interest to deal with damp and mould immediately. What could initially be sorted with some cleaning could quickly escalate to needing a wall knocked down or tenants rehoused. That is stressful for everyone.

Concluding remarks: 

  • We need to not only ensure improvements to existing housing stock but demand better quality for new housing stock too. We need to deal with airtightness and ventilation especially. Goldsmith Street is a good example of quality new stock.
  • Landlords need to be aware of their responsibility – that they know their buildings, know they’re in good condition, that they’re providing good vent systems & affordable heating systems, & asking reasonable things of tenants
  • Long term interventions are the key to improve the health of occupants and ensure sustainable use of resources. Her key takeaway is that it is much better to prevent the problem than deal with compensation later
  • We need to create healthy homes, not just cold/warm homes – ventilation, air quality and adequate warmth. Evidence that better housing improves health is out there.

And finally, why is opening windows in short blasts even when it’s cold outside beneficial? The fresh air makes the home cheaper to heat because the new air is less humid and drier air heats faster; and the fresh air will be healthier as it removes the damp. 5 mins a time, 2-3 times a day! 

Below is the event recording and some extra resources:

Recording of the event