Damp and mould advice
If you have damp or mould in your home, you're not alone. It can affect any type of accommodation.
Why it matters
Damp and mould can make you seriously ill. In rare cases, it can cause death.
Mould produces spores, allergens and other substances that are harmful to breathe in. It mainly affects your airways and lungs, but can also affect your eyes and skin.
You don't need to see mould to be at risk. Damp air on its own can help bacteria, viruses and dust mites to grow.
Damp and mould can also affect your mental health. This can happen because of the health effects, living in unpleasant conditions, or damage to your belongings.
Anyone can be affected. But you're at greater risk if you're a child, an older adult, or have certain health conditions.
What causes it
Most damp is caused by moisture building up inside your home — not by water coming in from outside, as many people assume.
The most common causes are:
- not enough ventilation
- not enough heating, or heat escaping through poor insulation or draughts
If poor ventilation is causing condensation, it usually means other harmful substances are also trapped in your home, even if you can't see or smell them.
Damp can also be caused by:
- leaks (sometimes called traumatic damp)
- water getting in from outside (penetrating damp)
- rising damp
Step 1
First steps
Remove the mould
Once damp and mould have been identified, the mould must be removed promptly to reduce health risks.
Mould and mildew products should be used in preference to bleach, as mould can react with bleach to create unhealthy chemicals. Absorbent materials such as carpets and soft furnishings may have to be thrown away if they become mouldy.
Check that everyone is OK
Seek medical advice if anyone is suffering from any asthmatic symptoms, headaches or tiredness that cannot be reasonably explained. Especially if the household includes babies, young children, expectant mothers or people with cancer-related illnesses.
Windows
Do what you can to create more airflow manually every day until a permanent solution is in place.
Open windows fully for five minutes at least twice each day, having first fully opened all internal doors. Then get it back up to temperature. If no one is in the property, keep windows closed after this.
You can put windows on the latch for rooms you are using but do not leave them like this for extended periods, as the walls around the window may get too cold and attract mould.
Doors
Keep internal doors open whenever you can (apart from the bathroom door when showering/bathing. Check there is at least a 10mm gap under every door (take advice on this point if any are fire doors).
Vents
Ensure all trickle vents are open and all extractor fans are used.
Furniture
Move furniture as needed so you can easily see all the inside of all external walls.
Step 2
Review the heating and insulation
Ideally, keep the house heated between 18- 21°C. 20°C is ideal during the daytime, with 18°C at night. 16- 17°C is the minimum for health, depending on health and age.
Time
The most important time to maintain temperatures is at night, this is when the house is cooling most and whilst moisture is being produced.
Don't let it get too cold
As the walls will get cold and may never get back to a good temperature, and mould is more likely to form.
Dropping the temp by 1°C to within the 18- 21°C range might save 13% of heating bills and is unlikely to affect condensation or mould. Do not allow any rooms to get really cold.
Keep it constant
The least efficient way to heat a home is a few hours' blast each day; keep the temperature constant.
Use thermostatic radiator valves (TRVs)
Use the TRVs to balance heat in rooms. If you have under-floor pipes, try to keep the TRVs as open as possible so more heat is radiated from them rather than the pipes. If this makes it too hot, drop the boiler temperature rather than close the TRVs.
Heat deflectors
Heat deflectors behind radiators on outside walls can reduce heat lost via the wall.
Bleed radiators
If the top of a radiator feels cold, bleed it by slowly twisting a radiator key and removing the air blockage.
Aspect
The worst problems tend to happen on the colder (north or east) walls. If you have a bedroom on that side with relatively more people in it given the room size, then consider moving people around if possible.
Wallpaper
If any wallpaper is damaged, consider removing it and leaving it as a bare wall (check with the homeowner first).
Internal insulation
If some localised places are particularly worse than others, internal wall insulation is a good thing to do, but be aware it may just move the problem until a permanent solution is in place.
Cold spots
Areas suffering black mould are saying they are too cold. For example, if there is mould on certain parts of the ceiling, it is alerting you that those parts of the ceiling lack insulation and need to be investigated.
Check the home's energy efficiency
It's increasingly expensive to heat homes. Investment in energy efficiency measures, such as improvements to heating systems, loft and wall insulation and glazing can be an effective means of increasing indoor temperature, but this must always be balanced by ventilation.
Loft insulation
Try to identify what can be done to improve the property's energy efficiency. Improving loft insulation to at least 270mm is a particularly effective means of keeping homes warmer. Many properties have less than 100mm.
Wall insulation
Improve external/internal wall insulation.
Pipes
Insulate hot water tanks and pipes.
Furnishings
Consider carpets and curtains to retain heat.
Windows
Consider replacing single-glazed windows with double glazing. Any double-glazing with condensation between the panes will need replacing.
People often think their double-glazing needs replacement because they can feel a draught. The truth is normally very different. When room air touches the glass, it cools, sinks and comes outwards off the inside sill. It feels like a draught but is just internal convection in the same way you can feel hot air rising from a radiator.
Draughts
Address true draughts (carpets and curtains may help here too). Bear in mind these draughts may be part of the current house ventilation. Do not cover vents.
Step 3
Reduce the moisture production
Understand the main culprits, cut down how much moisture gets stuck in the house and try to get rid of it naturally.
Showering
Try to reduce the length of time spent in the shower, as reducing water will make the biggest difference. Do not heat the room excessively before starting a shower. Changing the shower head for a 'low volume' one will really cut down on the steam and water used.
Drying clothes
Don't overload the washing machine and put it on an extra spin cycle before hanging up to dry. Leave clothes on hangers to dry through the daytime, not overnight, as this reduces the moisture load at night when risks are greatest and reduces the power cost for ironing.
Radiators (especially towel radiators) need to be kept uncovered. Try drying clothes in a warm room in sunlight between an open window and a good extractor fan.
Cooking
Keep lids on pots to reduce steam and put the extractor fan on before starting to cook, and keep it on for 20 minutes after finishing. However, this will only be effective if the fan outlet goes outside.
Unusual sources
Fish tanks and even large indoor plants can have a real effect on raising humidity.
Tackling a penetrating/rising damp problem
An independent damp surveyor is the most reliable starting point here to make sure the problem is correctly identified, and money is not wasted on unnecessary works.
Reputable damp companies may provide the same information or potentially more detailed information for less, but they make a living by selling their solutions.
Tackling a traumatic damp problem
Though traumatic problems are usually simpler to diagnose and less likely to need a specialist, an independent damp surveyor may still be the most reliable starting point to make sure the problem is correctly identified, and money is not wasted on unnecessary works.
This may be particularly important if the water ingress has been going on for a long time.
Step 4
Improve the ventilation
Keep extractor fan isolators switched on and only control them from the light switch. If the fan automatically comes on with humidity, adjust the setting and any timer so it starts quicker and stays on longer. If it starts coming on in the middle of the night, it's doing its job.
Intermittent fans
These must achieve high flow rates. Even new ones rarely do this. They also typically rely on three or four trickle vents per room or equivalent airbricks which must be kept open 24/7. This is not acceptable to most people due to draughts and heat loss.
Constant running extraction systems
Known as MEVs (Mechanical Extract Ventilation), with individual fans known as dMEVs (Decentralised Mechanical Extract Ventilation) are less common and more expensive but provide considerably more air-change, are more energy efficient and only ask for one or two open trickle vents in fewer rooms.
Positive Input Systems (PIV)
Provide still more air change and can usually dispense with the need for extraction fans or the otherwise obligatory reliance on open trickle vents. Most loft-based systems also promise an element of free heat.
Heat Recovery (MVHR)
The gold standard but many times more expensive and impractical for all but new builds or complete renovations. Relatively modern bungalows can be an exception to this rule.
Internal doors
Doors should only be kept shut to help contain moisture when trying to remove moisture, for example by an extractor from a bathroom.
Other than those exceptions, keep internal doors open as much as possible to allow moisture to be shared by the whole property, thereby minimising the increase in humidity.
Dehumidifiers
Dehumidifiers should be considered a short-term solution, ideal for traumatic damp but inappropriate long-term for condensation damp and often have maintenance requirements to maintain claimed efficiencies.
Unlike ventilation, they do not improve indoor air quality other than humidity.
Air bricks
Air bricks can help, but airflow rates are either unreliable or limited dependent on the type. They often either make the place too cold and/or give too much air change, or give too little and are ineffective.
Step 5
Understand everyone's responsibilities and seek help
Tenant's and their Landlord's each have responsibilities to work together to stop the problem.
A landlord:
Must provide a property fit for habitation
From the beginning to the end of the tenancy. This includes common parts if they are reasonably within the control of the landlord.
Must take steps to avoid damp
Such as avoiding damp ingress, providing effective insulation, providing efficient heating and sufficient ventilation.
Must ensure the home copes with normal domestic activities
Sufficient ventilation needs to be able to cope with moisture from normal domestic activities without the need for excessive opening of windows that could lead to heat loss, noise and security risks. It also means continuous low-level background ventilation where necessary.
Must be informed of the issue
A landlord's obligation starts once they have been told about the issue.
Must obtain necessary consent for the work
As a landlord may not be required to do otherwise necessary works if they cannot reasonably get any necessary consents to do the work.
May have a defence
If the problem was beyond their control, for example a flood.
A tenant:
Must use the property responsibly
Such as use the heating and ventilation responsibly and not to exacerbate the problem. For instance, not allow extra people to occupy the property than permitted.
Not withhold the rent
Without understanding this could result in eviction. Should tenants decide to do this anyway, they should keep it in a separate bank account so it can be called on instantly to pay the landlord.
Must inform the landlord
Of any issues they have with their home so that the landlord has the chance to rectify the issue.
Suggested approach
This is generalised to help most situations, and not everything may be correct for individual circumstances. Be aware that private tenants can face eviction without grounds being required using a Section 21 notice. Social landlords must have a clear and accessible complaints policy which the tenant must follow, as failure to do so may lead to delays.
Explain
The issue to the landlord and inform them what is being done to minimise the problem.
Act
On any reasonable suggestions from the landlord. Ideally, send your understanding of what was suggested to them.
Tell
The landlord by letter or email if the problem remains. Regular messages are best. The Landlord must both respond and effect repair in a timely manner.
Record
All conversations, correspondence, photographs of the defect, and anything the landlord has agreed to do. Keep receipts of all costs/replacements.
Advise
In writing, that if the issue is not resolved, we will be contacted for advice and assistance.
Find advice
Contact us to find out what action we can take to enforce the landlord to take action.
Councillors
May be able to assist by communicating with the landlord. Find your local councillor on our website.
Social tenants
Can go to their landlord's website and search for their complaints policy. Make a complaint giving as much detail as possible about what the complaint is and what the landlord has failed to do. Unresolved stage 1 complaints may lead to the tenant being able to make a stage 2 complaint.
Tenants
Can go to court for breach of contract. This can lead to compensation and works. They would need a solicitor to take the case and find out how much they will charge.