Ceiling mould


A question regularly asked, especially as winter approaches is “how to prevent condensation and mould in the home”.

There are many reasons why some homes get Mould. Condensation and Mould can make a home very uncomfortable. Mould can harm a person’s health, and condensation can make the house uncomfortable. Let us look at a few options to reduce condensation and Mould in the home.

Condensation Explained

Before you can work toward remedying your home’s condensation problem, let’s take a closer look at how it forms. Water passes from a vapour to a liquid state and builds upon cooler surfaces.

The condensation level and the ceiling mould potential can vary depending on your climate and the air’s humidity level. But no matter where you live, changing temperatures can create a problem on and inside your roof.

Aside from the climate, everyday activities like Cooking, dishes, and even talking can create a higher condensation level. When steam is generated into the air, it can start to saturate and deposit the water vapour onto your roof.

Your walls, roof, and ceilings are usually the coldest surfaces of the home. Without proper insulation or ventilation of your roof, condensation and Mould can easily begin to grow.

When the water temperature passes from the vapour state in the air to a liquid state, condensation forms; in a humid environment, this water deposits onto surfaces and your roof, where it sits stagnant.

When water sits for too long, it’s no surprise that Mould will eventually follow. You can ensure a drier roof and home interior by removing the excess water buildup from the equation.

During the winter months, you may notice that condensation levels are even higher. t results from bad insulation in the home because cold air gets in, and then it gets trapped in the warm, humid air due to lack of ventilation.

Signs of Ceiling Mould and Condensation Problems

At first glance, you might not be able to see any issues with condensation on your roof easily. But upon further examination, there are a few red flags that should concern you.

First, look for black stains on your walls or ceilings, as this is a good indication of the presence of Mould in your home. If your furniture seems brittle or deteriorating, it’s because it’s subjected to constant moisture.

Take a closer look at your windows and glass door. If you notice fogging, mist, or sweating, this results from too much condensation accumulating.

Another common problem related to your roof could be leaking. If condensation builds up too much or too quickly, it can cause serious damage to your roof’s structure, resulting in pesky leaks.

Smell the air in your home, and be aware of any new mildew or musty smell. It could mean that there’s too much condensation inside your home.

Without proper remediation, you could suffer a variety of health conditions. These include anything from allergies to asthma or headaches and severe respiratory issues.

Not only is condensation and ceiling mould unattractive, but they can also harm your health! That’s why ensuring that your roof has the proper insulation and ventilation is important to keep this problem at bay.

When Mould builds up around your walls and on your ceiling, it results in costly repairs and a thorough evaluation of the home. Thankfully, there are some things you can do to keep this problem from occurring in the first place.

Is Mould dangerous to health?

Mould produces allergen. These are substances that can cause an allergic reaction. Mould can cause irritants and, sometimes, a toxic substance. Inhaling or touching mould spores may cause an allergic reaction in some people, such as sneezing, a runny nose, red eyes and skin rash. Mould can also cause an asthma attack. Need more info? Read this.
condensation and mould are harmful
Find Out More About The Harmful Effects of Mould


What Causes Mould in The Home

  • In winter, when it is colder, mould growth is evident.
  • On a cold winter day, it is noticeable that there is almost what looks like steam coming out of our mouths when we breathe.
  • Warm air comes in contact with the cold outside air.
  • Many factors will cause Mould, so let’s look at a few.
  • If your home is freezing in winter, your ceiling will be mouldy.
  • A leaking window will allow the outside cold air into the home.
  • Leaking doors are also a big culprit in allowing cold air into the home.
  • Very thin curtaining will allow cold air to radiate into the home through the glass window.
  • Lack of proper insulation is a significant factor.
  • If your home has cold air and no insulation, your ceiling will be freezing from the roof above.
  • It means the warm air our bodies breathe will rise and cause moisture on the ceiling.
What causes condensation
What causes condensation

How Can We Prevent Mould On Our Ceilings

  • One of the best ways to reduce Mould in your ceiling is to insulate your roof with roof insulation.
  • There are many roof insulation products on the market.
  • However, the 135mm Aerolite and the 145mm Isotherm insulation have a high R-value and are very effective at reducing Mould.
  • The roof insulation will reduce the ability of the ceiling to retain the cold from the roof above.
  • Windows are another big area of mould concern.
  • Try and seal the windows, so they do not leak cold air into the home.
  • One can purchase thin rubber window sealers that can be fitted around the window frame to reduce the cold air entering the home.
  • Fit aluminium windows as this seal quite well.
  • The best would be double-glazed windows to reduce heat and cold entering the home substantially. With the bonus of sound reduction as well.
  • Heavy curtaining, and by this, we mean heavy curtains.
  • The curtain rails must also be a little wider than usual.
  • The heavy curtains provide insulation between the window and the home inside.
  • Rugs on the floors or carpeting can also help reduce the cold air in the room.
  • Seal all doors. Air leakage will increase the risk of condensation.
  • Fit door scoops at the bottom of the entrances to prevent cold air from coming into the home.
  • Reducing cold air in the home is essential for this exercise.
  • The home will be more comfortable.
Harmful effects of mould in the home
Harmful effects of Mould in the home

How to Fix Bathroom Mould

Having a hot shower in some bathrooms, even when the windows are open, can cause this. So what do we do no? Insulation will make a difference; however, we suggest fitting a ceiling extractor fan for this application. It can be installed above the shower and pull the condensation air into the roof. That will not create Mould on top of the ceiling from inside the roof as the insulation barrier you have installed is in place. Mould and associated Bacteria are harmful to any family.

Things that Affect Mold and Condensation

Proper ventilation is needed to keep the home comfortable and free from Moul. Roof ventilation is crucial for the comfort of the house. Some things the homeowner does and does not realise are reducing the ventilation.

Installing double-glazed windows or doors reduces natural ventilation. Draught excluders will keep fresh air from entering the home. Fitted carpets prevent the air from moving up through the floor, keeping the air in the room still. Central heating systems may keep the house warm but prevent fresh air from getting in.

Houses can become sealed up like a box, and this is a condition that will cause condensation to develop. Fresh air cannot get into the home, and the air in the home cannot escape it.

Condensation happens when warm, moist air can contact dry and cool air. It can also develop on a surface with a lower temperature than the rest of the water.

Air then turns into water vapour, and when it comes in contact with a cold surface, the moisture from the air will release water onto that surface. That forms condensation. A person will notice condensation when it starts on windows and other surfaces that cannot absorb the moisture. It can start on any surface in the home but may not be noticeable until Mould begins to grow or the surface begins to rot.

Roof Ventilation Benefits

Whirlybird roof ventilators can remove moisture from the air and keep the air moving around the house. When condensation forms due to poor air circulation, such as on the baseboards, it is easy for Mould to grow. It can also leave a musty smell on the house and clothes.

Regular activities will fill the air with moisture and then condensation. Some factors will depend on how much water is in the air.

They are :

  • Moisture in the air will depend on the water sources in the home.
  • Water vapour is in the air from daily activities.
  • The average family put around 10kg of water in the air without knowing it.
  • Also, without having a heating system turned on.

Breathing will put around .3 kg of moisture in the air, even when sleeping. When awake, this number rises to .85k . Cooking daily puts 3kg of moisture into the air. Washing will add another 1 kg to the ai. Washing and drying clothes will add 5.5 kg to the atmosphere.

Having a shower and Cooking contribute to more water vapour in the air. If the moisture lands on external walls, it can build you. The clothes dryer will put additional humidity into the home, leading to mould development. The more people live in the house, the more moisture they put into the air without even knowing it.

Temperature changes can lead to the development of condensation. The more people in the home, the more water vapour is put into the air due to respiration. The more insulation the house has, the higher the temperature will b. If Mould begins to grow, it can hold water and lead to additional mould growth.

Install Ceiling Insulation

Ceiling insulation is a barrier between the cold roof space and the house. When we add Ceiling insulation, we have a more stable indoor temperature. Insulated homes have an improved indoor temperature of 5-8 degrees in summer and winter. Installing 135mm Aerolite Insulation or the 135mm Knauf Ecose will reduce condensation substantially. However, it is advisable also to have Roof Ventilation units installed for added protection.

How to Reduce Mould and Condensation

There are steps we can take to limit the development of condensation. We must dry our clothing outside to keep the humidity levels down in the home. Remove furniture away from the external walls to allow them to get air. If a homeowner notices mould, a professional should remove it right away. An extractor fan will reduce the moisture levels in the kitchen and the bathroom.

Install roof insulation in the roof space to reduce the impact of cold winter. Add Whirlybird roof ventilators to remove moist, damp air from the roof space.

Lady blowing her nose because of moist damp air damage in the house
Condensation and Mould lead to allergies

How Ventilation Helps

Ventilation will keep water from turning into condensation. It will also keep the humidity levels low.

Exterior fans

The fans will keep the air pressure inside and outside the home equal. Changes in the ventilation will affect the temperature and the amount of water pressure.

Intake Ventilation Solution

  1. An intake fan will keep the air blowing to create a pressurised environment.
  2. The water vapour will equalise before it forms condensation.
  3. We can then lower the level of the dew point.

Advantages of Intake Air systems

  • Reduces condensation formation
  • A single unit Intake Air System will work well
  • We can increase the dynamic U value
  • There is a central point for installation


  • Reduce the thermal properties in the building fabric
  • May not conform to building regulations
  • It is expensive to operate
  • We need to replace the filters regularly
  • Additional heat is needed to keep the home at a suitable temperature
  • It is not an environmentally friendly solution
WhirlyBird Roof Ventilators remove airborne moist damp air
WhirlyBird Roof Ventilators remove airborne moist damp air

Whirlybird Roof Ventilators

Roof ventilation systems suck moist, damp air out of the roof space. Whirlybird Roof ventilators will remove damp stale air from the roof space reducing condensation substantially with insulation. The vapour pressure will still be high, but the lower air pressure will let the air get around the home. The interior walls will lose some heat and will become more relaxed. This system may be affected by the dew points.

Roof Ventilation System Advantages

  • This system can reduce the development of condensation at the source
  • It is adaptable to any home and can be fitted in under an hour
  • Will meet with building regulations and requirements
  • It has a low cost
  • Increases thermal efficiency in the home
  • Is energy efficient to run
  • There is almost no maintenance cost
  • WhirlyBird Roof Ventilation is an environmentally friendly solution

These are some ways that a person can reduce condensation in their home. By reducing the amount of water put into the house, a person will live comfortably and reduce the chance of Mould developing.

Other Ways to Stop Condensation

Now that you know more about the importance of roof insulation and ventilation, what else can you do to keep moisture at bay? A few simple tweaks in your lifestyle can make a big difference in preventing condensation and Mould.

Firstly, open your windows on warm days to “air out the home.” This simple act can dry out anything accumulated condensation or exposed to interior humidity.

Use a dehumidifier if you live in areas where humidity is an issue. This helpful appliance can be placed in any room and will keep moisture levels to a minimum.

Think of every activity you do that produces excess heat. Anything from washing dishes and drying clothes to Cooking and taking hot baths or showers will create additional moisture and heat.

Use exhaust fans and vents in the bathroom or kitchen whenever possible to reduce the moisture in the air. Keep your dryer vents clean and free of lint and other debris for better airflow.

Keep the lids on pots as pans for as long as possible when you cook. Turn on your bathroom vent whenever you take a bath or shower.

Anything you can do to reduce the air’s moisture will help prevent condensation from forming on your windows, walls, and roof.

Another tip? Reduce the number of houseplants in your home. Although they’re beautiful and can clean the air, they can also increase moisture inside the house.

While there is no single magic solution to moisture problems, anything you can do to ease the amount will make a difference. Please pay close attention to any moisture troubles before getting them out of hand for the best results.