Damp and Condensation Mould

Damp and condensation mould is not one thing, it's two separate things, which are both potential hazards.

We have systems in place to help make sure that your home is free from hazardous levels of damp and condensation mould and to identify and deal with cases promptly and effectively.

What is damp, condensation and mould

Moisture builds up quickly in kitchens and bathrooms, and condensation is more likely in colder, unheated spaces. These guides share simple steps to reduce humidity, improve airflow and lower the risk of mould in the areas most commonly affected.

Damp Damp is unwanted moisture in a building. It can come from leaks, rain getting through walls, or moisture rising from the ground, and can damage walls, floors, and furnishings.

Condensation Condensation happens when warm, moist air meets a cold surface and turns into water droplets. It is common in kitchens and bathrooms and is often caused by poor ventilation.

Mould Mould is a type of fungus that grows on damp or wet surfaces. It often appears as black or green patches and can affect both the building and people’s health.

Watch our handy video which explains more!

This short video explains damp, condensation and mould in a clear, easy way. It shows how everyday things like cooking, showering and drying clothes put water into the air, and how that warm, wet air can turn into tiny water drops when it hits a cold wall or window. If those drops stay, mould can start to grow. It also explains that some damp comes from leaks or water getting in from outside.

Watch the video to see what’s going on in the home and what simple steps can help reduce condensation and mould.

What is the difference between damp and condensation mould?

In most cases, mould growth is a result of condensation, though it can be made worse by damp.

While condensation cannot be completely cured, it can be managed effectively, and this is something we can work on together to minimise its impact.

Damp is a more serious issue and can be resolved through appropriate remedial action, which is our responsibility.

What typically causes condensation and what does condensation mould look like?

Condensation happens when humid air meets a cold surface.
When these tiny water droplets reach a cold surface, they clump together.
'Dew point' is when they form visible drops, and condensation forms on the surface.

The more moisture there is in the air the more likely it is you will get condensation.

Condensation can lead to mould if left for too long.

Mould is a natural organic compound, and mould spores exist all around us in the air and are brought into our homes every time we open a door or window or on our clothes when we come in from outside. For mould to grow and spread it needs clean water (produced by condensation) and if it has a food source (dirt, dust and bacteria) it will grow and spread even quicker.

Take these two things away and the mould spores will not be able to grow.

Above: Mould growing.

Below: Condensation on the glass running onto the sill.

Above: The condensation needs to be removed/reduced daily in order to reduce the possibility of Mould forming.

This can happen in any home and is not purely a social housing issue.

Other conditions that increase the risk of condensation

Inadequate ventilation - windows that don't open, broken or ineffective extraction fans.
A lack of heating - not heating the house which may be a result of fuel poverty or a broken appliance
Leaking pipework – the water will evaporate and add to the moisture in the air
Defective insulation – poorly fitted loft insulation will leave cold spots on the ceilings
Poor building design – bathrooms with 3 external walls will have greater heat losses and will need more ventilation
Over filled rooms – restricts ventilation as air will not circulate around the items

Overcrowding – every person adds about 4 pints of water a day to the moisture level in the home. More people mean more moisture and more ventilation and management needed.

Dampness can enter the building through the foundation walls from the wet ground. Cracks on the surface of walls, slabs, terraces, roofs, etc., allow the entry of moisture during rainy weather seasons.

There are two main types of damp that we encounter.

Rising damp and penetrating damp, both of these can contribute to condensation mould.

Rising damp

This type of damp is caused when water in the ground or a surface level rises through the structure of the property as a result of the failure, breach or lack of a moisture control barrier.

These are namely the damp proof membrane, a solid floor or the damp proof course in a ground floor wall.

This is typically what you will see on the inside: rising damp coming up through the walls.

Rising damp coming through the floor will likely lift vinyl tiles and soft furnishings may suffer from mould.

Rising Damp - typically this is what you would see on the outside of the property: Damp brickwork above the damp proof course level which should be 150mm or 2 courses of brickwork above the external ground level.

Rising damp - damp brickwork above the damp proof course level

Penetrating damp

Penetrating damp is caused when there are defects in the structure that allow water to pass through the fabric of the building. This can be a leak from a pipe internally or externally, a leaking roof, damaged brickwork or poorly sealed windows and doors.

Typically, penetrating damp will look like this internally: penetrating damp on a chimney breast.

Penetrating damp through a chimney breast

Penetrating damp through a leaking roof.

This is what you would see on the outside that could cause penetrating damp:

Penetrating damp - loss of mortar in the brickwork joints

Blocked guttering overflowing roof:

Cracked and damaged rendering:

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How to prevent damp and mould in your home

The most effective way is to reduce moisture and condensation through heating, ventilation and wiping away condensation from surfaces. We have practical, room-by-room advice on our How to prevent damp and condensation mould page.

Find out more about preventing mould

How we deal with reports of Damp and Condensation Mould

When you raise any damp and condensation mould concerns, we will log the issue and check what is happening, often starting with a video call to look at the problem and give advice. If needed, we will arrange a home visit to investigate and plan repairs, and then follow up to make sure it has been sorted.

Read our full step-by-step process