Condensation on Walls? 5 Keys Signs & How to Fix it

A family of two adults and two children produce around 15 litres of moisture per day. Many everyday activities like showering, cooking, and even breathing contribute to this build-up, which can lead to condensation. 

Condensation forms when warm, moist air meets cold, hard surfaces, such as windows and walls. You may notice condensation:

• In kitchens when cooking
• In bathrooms when showering
• On bedroom windows first thing in the morning

It is often seasonal and appears as the temperatures drop. Although a small amount of condensation is normal in homes, excess moisture can cause damage to your property and affect your health.

Simply put, humidity is the amount of water vapour in the air, and it plays a key role in the formation of condensation. 

High humidity means more moisture in the air, which is more likely to turn into water droplets when it touches cooler surfaces like windows and walls. 

Showering, cooking and even rainy weather can increase indoor humidity. If you often see condensation on your windows and walls, it may be a sign that the humidity levels are too high.

How can you tell if your home has a condensation problem? Sometimes it may be obvious, but here are some common signs that you may not be aware of: 

1. Water droplets on windows and walls

Water droplets forming on windows and walls is the result of condensation - the process of warm, moist air coming into contact with a cold surface turning the warm vapour into a liquid. 

2. Mould growth

Mould can form anywhere there is moisture, oxygen and warmth, typically forming in areas around windows, damp corners, cupboards, etc.

3. Musty smells

Condensation can cause mould, which in turn, can produce a stale, unpleasant smell. The smell is much more prevalent in enclosed spaces where there is little room for fresh air to circulate. 

4. Damp patches on walls

These may be more apparent on painted walls but less obvious on walls that have been covered with wallpaper. Simply touching the wall with your hand can tell if the wall has a damp spot or staining signs. 

5. Peeling wallpaper

Condensation can cause wallpaper to peel from the walls. This is because the surface behind the paper will become damp and the paper is no longer able to stick properly. 

It's important to act quickly at the first signs of condensation and mould. If left unaddressed, condensation and mould can lead to damaged furnishings, structural damage and health issues, such as asthma & other respiratory conditions. 

Here are 6 simple ways you can prevent condensation and mould in your home: 

1. Clean mould and condensation away

Wipe away condensation from windows and walls to stop mould from forming. If there is already mould in your home, remove it from affected surfaces so that it doesn’t spread any further.

1. Walls - wash down with a mould removal product and dry them thoroughly.
2. Soft furnishings – have them professionally dry cleaned.
3. Badly affected items - Throw away any items that have been damaged beyond repair.
4. Leave your windows open so the room dries quickly.
5. Vacuum the room to ensure no moisture soaks into the floor.

Top tip: Mould spores can be harmful to your health so remember to wear a face mask and gloves when using products to remove it from your home.

2. Keep your home dry and well ventilated

Condensation is often a result of airtightness and poor ventilation. According to BRE, the majority of condensation issues in modern houses have been due to a lack of ventilation.

Many people are striving to create an energy efficient, airtight home by adding high levels of insulation and double/triple glazed windows are often installed. However, without sufficient ventilation, there is nowhere for moisture to escape. Therefore, one of the best ways to reduce condensation and prevent mould is to provide adequate ventilation.

There are a number of ways to ventilate your home and provide air flow in and out of your home:

• Opening windows and doors
• Using extractor fans in bathrooms and kitchens
• Trickle vents on windows
• Installing a Mechanical Ventilation system

3. Don't dry clothes indoors

Drying your washing indoors over radiators increases moisture levels within the home and can add a whopping 10-15 litres of moisture to your home in a week!

During winter, when it’s more common to dry clothes inside, humidity levels are usually higher. It’s recommended that you dry your clothes outdoors when possible or use a tumble dryer that's vented outside.

Top tip: If drying your washing outside isn’t an option, try using a room that is well ventilated, with an open window for example, to allow the moisture to escape outdoors.

4. Keep doors closed

When cooking or showering, humidity levels in kitchens or bathrooms dramatically increase. To prevent damp, moist air from spreading throughout the rest of your home and causing condensation, keep internal doors closed. Remember to turn on extract fans and cooker hoods if you have them so that some of the moisture is vented outside.

Top tip: Keeping doors closed will reduce condensation but won't solve the issue. Without proper ventilation, condensation may still settle on walls, ceiling and other surfaces in areas with high levels of humidity leading to mould growth.

5. Clear out the clutter!

Areas in the home where there is a lot of clutter or items packed tightly together can be prone to mould growth as air circulation is restricted. Check your cupboards, drawers and wardrobes - if they are overfilled, try having a clear out or moving some of their contents elsewhere. This will allow the air to circulate freely inside.

Top tip: A stale or musty smell is a sure sign that your cupboards are overfilled!

6. Check for leaks

As we now know, mould loves moisture! It can often be found in places that have experienced leaks or excess moisture build up. These areas may not be as obvious as a ceiling or around a window, so it is worth checking in other areas of the home as well.

Top tip: Check for leaks under sinks, behind toilets, around your washing machine and dishwasher, and under radiators. These are all common places where leaks can occur, and mould can begin to grow and spread.

These tips are a great way to help reduce condensation and mould, but the key to prevention is proper ventilation, ensuring adequate airflow throughout your home.

The best way to make sure your home is being properly ventilated is with a Mechanical Ventilation System.

Suitable for existing homes, a BEAM Positive Input Ventilation (PIV) unit gently ventilates the home from a central position in the hallway/landing. This compact condensation control unit is usually placed in the loft-space above the hallway. It replaces stale, moist air with fresh, filtered air, reducing condensation and mould.

For new build homes, a BEAM Heat Recovery Ventilation (MVHR) System is an excellent solution to reduce condensation and prevent mould. The whole house ventilation system constantly supplies fresh, filtered air into habitable rooms while stale, moist air is extracted from wetrooms such as bathrooms, kitchens and utility rooms.

Another option to help reduce condensation and mould is BEAM’s Mechanical Extract Ventilation (MEV) System. The low energy system continuously extracts stale, moist air from wetrooms at a low rate. When high humidity levels are detected (i.e. when showering), it automatically boosts extraction rates to effectively remove moisture. This is a fantastic, energy efficient alternative to multiple extractor fans.