Understanding damp issues in homes: causes and solutions

We all have the right to a warm and secure home. Yet, according to government statistics, damp and mould exists in up to 27% of UK properties. Not only can it put the condition and value of your property at risk, but it can also play havoc with your health.

If you’re a property owner or tenant with damp or mould in your living space, here’s what might be causing the issues – and how it can be rectified with the right professional care and treatment.

The five types of damp we investigate

Damp is not a single problem. The right repair depends on which type of moisture movement is happening, and many properties show more than one at the same time.

Penetrating damp

Penetrating damp occurs when water moves horizontally through a wall, roof, ceiling or floor from the outside in.

The usual culprits are leaking gutters, blocked downpipes, defective pointing, cracked render, failed flashings or porous brickwork. The fix is almost always to repair the building fabric – not to inject chemicals.

Condensation damp

Condensation is the most common form of damp in modern UK homes. It occurs when warm, moisture-laden air meets a cold surface and the water vapour turns into liquid – typically on windows, in corners, behind wardrobes or on poorly insulated walls.

It’s usually a ventilation, heating or insulation problem rather than a defect in the building, and the cure is rarely a damp-proof course.

Rising damp

Rising damp is moisture drawn upwards from the ground by capillary action through walls and floors that lack an effective damp-proof course (DPC).

True rising damp is far less common than treatment companies often claim, and is frequently misdiagnosed.

We use moisture profiling at multiple heights to confirm whether moisture is actually rising or whether the readings are explained by another cause, such as a bridged DPC, raised external ground levels or condensation.

Traumatic damp

Traumatic damp is caused by a sudden water event – a burst pipe, a leaking shower tray, an overflowing tank or a failed appliance.

The water source needs to be repaired and the affected materials properly dried out before any cosmetic repair, otherwise the problem will return.

Mould

Mould is a fungus that thrives wherever there is moisture and stagnant air.

It is not just a cosmetic issue: spores can affect respiratory health, particularly for children, the elderly and anyone with asthma or a compromised immune system.

Identifying and removing the underlying moisture source is essential – wiping mould off the wall without addressing the cause will only delay its return.

Managing mould and damp in your property

The first step to managing mould and damp is to find the cause. With condensation damp, for example, you should identify where moisture is coming from and the number of routes it has to escape. For example, a shower room with no windows or poor extraction invites condensation to settle on cold surfaces which, over time, will form into a fungus.

There is no cure for condensation – it’s a substance produced by every property in the UK. But there are some simple actions you can take to reduce the likelihood of moisture settling on your surfaces.

  • Replace wet air with dry air by allowing proper ventilation (e.g. windows, extractor units)
  • Raise the temperature of cold surfaces (e.g. underfloor heating)
  • Raise the temperature of the air

By maintaining a habit of opening windows or using your heating wisely to counteract the impact of condensation, the harder it becomes for mould to spread in your property.

How to treat rising damp

Before you treat rising damp, it’s essential to get an accurate diagnosis from a qualified professional such as a surveyor. You’ll get clarity on the cause of damp as well as expert guidance on the right type of remedial work.

In most instances, rising damp is caused by a failed, broken or missing Damp Proof Course (DPC). It means moisture can penetrate property materials in contact with the ground, and slowly rise to damage internal and external walls – often without you noticing until it’s too late.

Remedial work to prevent rising damp can be extensive and will often involve replacing the damp course with a new membrane, DPC injection or both. It’s also the case damaged external and internal materials will need replacing once the new DPC has been installed, which varies in fees from one property to the next.

Signs you may need a damp survey

You might benefit from a damp survey if you’ve noticed any of the following:

  • Tide marks, staining or salt deposits on internal walls, especially within a metre of the floor
  • Black, green or grey mould patches – commonly around windows, in corners, behind furniture or in bathrooms
  • Peeling paint, blistering plaster or wallpaper lifting away from the wall
  • A persistent musty smell, particularly when a room has been closed up
  • Cold spots on walls, condensation forming on windows, or steamed-up glazing in the morning
  • Damaged or perished skirting boards, floor timbers or window frames
  • Recommendations to investigate further following a RICS Level 2 HomeBuyer Report or Level 3 Building Survey
  • A buyer, lender or insurer asking for a specialist damp report before completion
  • A leak, flood or burst pipe that you suspect may have caused longer-term damage

Get in touch

If you’re experiencing damp or mould in your property and need an expert diagnosis, get in touch with our team today. We can advise on the right treatment and project manage the remedial work for you.