Condensation control for existing homes

Condensation is defined as the process where water vapour in the air transforms into liquid water when warm air comes into contact with a cold surface below the “dew point”. At dew point, water droplets will form on a surface in the same way that they do on the outside of a bottle of a cold drink on a hot day. Condensation can also occur in homes due to the vapour that is created by showers, cooking, kettles and everyday living. In colder parts of Australia care needs to be taken to ensure this warm air condensates on the outside of the home and not inside.


When condensation does occur inside the home it can appear on windows where we can see it, or worse, hidden behind plasterboard walls or ceilings. This can lead to staining of the plasterboard, wood swelling, long term structural damage and mould growth in inaccessible areas within the building structure.

To reduce the risk of condensation and the health issues associated with mould formation, here are some suggested changes that can be made to existing homes to improve condensation issues:

  • Externally duct: Controlling moisture inside the home and attic space by ducting bathroom exhausts, range hoods and other appliances that generate warm, moist air to the outside environment is strongly recommended as these moisture sources all add water vapour into the air.
  • Ventilate: Its always considered good practice to ventilate the attic space to remove warm, moist air away from the cooler outside surfaces of the house which helps to reduce the risk of it contacting cooler inside surfaces of the roof.
  • For more complex solutions, the use of a powered ventilation may also be required, or the services of an experienced insulation specialist to assess the most appropriate solution.
  • In hot/humid climates, the addition of ceiling insulation may also assist in controlling condensation by reducing the transfer of conditioned cold air to the warm outer surfaces of the home.

Ideally, condensation management should be considered prior to construction so that the correct combination of insulation and wall wrap can be specified when you build. To learn more about which parts of Australia are most susceptible to condensation issues please contact CSR Bradford technical specialists or refer to our comprehensive range of brochures.

A highly vapour permeable, tough, light duty wall wrap for use as a sarking in timber and steel frame wall construction.
A range of wall wrap products provide a secondary protective skin to your home which can reduce draughts and help make your home more comfortable.
A high tensile roof underlay designed to reduce the risk of condensation damage and weather related water entry in the roof.
Multi-layered non-permeable membrane specially made for residential roofs to help insulation work more efficiently and protect the things you value from storm driven rain and dust, condensation and bush fire ember attack.
Designed specifically for metal roofs, Bradford Anticon combines Bradford glasswool blanket with an impermeable foil facing, that protects your home from the condensation that can form under metal roofs.
Energy efficient, innovative home ventilation for comfortable living. Brought to you by CSR Edmonds.
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