Ceiling mold

A question asked on a regular basis, especially as winter approaches is “how to prevent mould in the home”. There are many reasons why some homes get mold. In this post, we will try and help with ways to prevent mould in the house. Condensation and mould can make a home very uncomfortable. Mould can be harmful to a person’s health, and condensation can make the home very uncomfortable. There are some things in the home that can lead to the growth of mould and the buildup of condensation.

Is Mould dangerous to health?

In fact, Mould produces allergens. These are substances that can cause an allergic reaction. Mould can cause irritants and, sometimes, toxic substances. Inhaling or touching mold spores may cause an allergic reaction in some people such as sneezing, a runny nose, red eyes and skin rash. Mould can also cause asthma attacks.

What Causes Mould in The Home

  • In winter, when it is colder, mould growth is far more evident.
  • On a cold winter day, it is noticeable that when we breathe out, there is almost what looks like steam coming out of our mouths.
  • Warm air coming in contact with the cold outside air.
  • Many factors will cause mould so let take a look at a few.
  • If your home is freezing in winter chances are your ceiling will be mouldy.
  • Leaking window will allow the outside cold air into the home.
  • In fact, leaking doors are also a big culprit in allowing the cold air into the home.
  • Very thin curtaining will also allow cold air to radiate into the home through the glass window pane.
  • Lack of proper insulation is a significant factor.
  • If your home is cold with cold air coming into the house and you have no insulation your ceiling will be freezing from the roof above.
  • This will mean the warm air that our bodies breathe out will rise and cause moisture on the ceiling.

How Can We Prevent Mould On Our Ceilings

  • One of the best ways to reduce mould in on 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 concern for mould.
  • 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 effect of the cold air entering the home.
  • If you have the money fit aluminium windows as this seal quite well.
  • The best would be double glazed windows as they will reduce heat and cold entering the home substantially. With the bonus of sound reduction as well.
  • Heavy curtaining and by this, we mean very heavy curtains.
  • The curtain rails must also be a little wider than usual.
  • The heavy curtains act as a form of insulation between the window and the inside of the home.
  • Rugs on the floors or carpeting can also help reduce the cold air in the room.
  • Doors need to be sealed.
  • In fact, fit door scoops at the bottom of the doors to prevent cold air coming into the home.
  • Reducing cold air into the home is the most important part of this exercise.
  • This will make your home more comfortable and your family more healthy and happy.

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 now? Insulation will make a difference; however, for this application, we would suggest fitting a ceiling extractor fan. This can be installed above the shower and will pull the condensation air into the roof space. That will not create mould on top of the ceiling from inside the roof as the insulation barrier that you have installed is in place. Mould and associated Bacteria are harmful to any family.

Things that Affect Mold and Condensation

To keep the home comfortable and free from mould, proper ventilation is needed. Roof ventilation is extremely important for the comfort of the home. There are some things that the homeowner does and does not realise they are reducing the ventilation.

Installing windows or doors that are doubled glazed 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 stale. Central heating systems may keep the home warm, but they keep fresh air from getting in.

Houses can become sealed up like a box, and this is a condition that will cause condensation to develop. They are sealed up good so that fresh air cannot get in the home, and the air in the home cannot escape from it.

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

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

Roof Ventilation and Insulation

Whirlybird roof ventilators can remove the moisture from the air and keep the air moving around the entire 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 even the cloths.

There are normal activities that will fill the air with moisture and then turn it into condensation. Some factors will depend on how much water is deposited into the air. They are :

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

Breathing will put around .3 kg of moisture in the air, even when a person is sleeping. When awake, this number raises to .85kg. Cooking each day puts 3kg of moisture into the air. Washing will add another 1 kg into the air. Washing and drying clothes will add 5.5 kg to the air.

The more a person cooks and the more showers that are taken at home will put water vapour into the air. If the vapour lands on external walls it can build up. The clothes dryer will put additional humidity into the home, which can lead to the development of mold. The more people that live in the home, the more moisture they are putting into the air without even knowing it.

Changes in temperature 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 be. If mould begins to grow, it can hold water and lead to additional mold growth.

How to Reduce Mould and Condensation

There re some things that can be done to limit the development of condensation. The clothes should be dried outside to keep the humidity levels down in the home. Furniture should be kept away from the external walls to allow them to get some hear. If a homeowner notices mold it should be removed by a professional 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 winters. Additionally, add Whirlybird roof ventilators to remove moist, damp air from the roof space.

How Ventilation Helps

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

Exterior fans

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

Intake Ventilation Solution

An intake fan will keep the air blowing to creating a pressurised environment. The water vapour will equalise before it forms condensation. The heat will not be trapped in certain areas of the home. The dew point will be kept at a lower level.

Advantages of Intake Air systems

  • Reduces condensation formation
  • A single unit is used
  • The dynamic U value will be increased
  • There is a central point for installation


  • Reduce the thermal properties in the building fabric
  • May not conform to building regulations
  • It expensive to operate
  • The filters will need to be replaced
  • Additional heat is needed to keep the home at a good temperature
  • This is not an environmentally friendly solution

Whirlybird Roof Ventilators

This will allow the air to blow around the property. The vapour pressure will still be high, but the lower air pressure will let the air to 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. Whirlybird Roof ventilators will remove damp stale air from the roof space reducing condensation substantially with insulation.

Roof Ventilation System Advantages

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

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