Dampness and condensation issues in rental properties

Condensation

The winter months can cause condensation issues - especially in the cooler parts of our country. When air is warmed inside a property it will hold water vapour. 

The more heating we use, the more water vapour that will be held. When that air comes in contact with a cold surface, condensation occurs - most often on the windows.

Other activities that can cause condensation include:

•    Cooking
•    Having a shower or bath
•    Drying clothes inside
•    Doing gym work
•    Using a clothes dryer that is not ventilated
•    Using heating that is not flued.

Minimisation and prevention

Ventilating a home is important to prevent condensation and avoid damage being caused to a property.

Condensation can be minimised by:

•    Using a heat pump to maintain the temperature of the rooms at a minimum of 16 degrees.  
•    Ensuring the bathroom is fitted with a proper exhaust fan. If not, it's important to open a window to let the steam out.
•    Having a proper extractor fan in the kitchen. This should be ducted to the outside of the property.  
•    Wiping away condensation on windows each day.
•    Ventilating cupboards regularly by leaving the doors open.
•    Ensuring that any leaks are reported to your property manager/landlord immediately so these can be repaired as soon as possible.  

If a property is not properly ventilated, this can damage the home and affect the heath of its occupants.

Damage might include:

•    Mould growing in the property – especially in bathrooms, behind beds and in cupboards.
•    Damaging wood in a property – particularly around windows where condensation has not been removed. The damage can lead to window sills rotting.
•    Damage can also occur to wallpaper, plasterboard, linings and carpets.

Warmer, safer and dryer homes

Under the Residential Tenancies Act 1986 amendments, all properties must have ceiling and underfloor insulation fitted by 1 July 2019. Some exemptions will apply – e.g. if there is not enough space under the floor of the home to insulate it. 

Learn more about the insulation requirements on the tenancy.govt.nz website or speak to your property manager. 

Insulating, adding good extractor/exhaust fans, and ensuring a property is ventilated will help minimise the impact of condensation.