How dampness enters our homes

Moisture makes its way into your home in many ways, including cooking, showering, water leaks from the roof and windows and even breathing. Photo / Getty Images

Did you know, a family of four can produce 34 litres of moisture a day through everyday tasks?

Moisture makes its way into your home in many ways, including cooking, showering, water leaks from the roof and windows and even breathing.

Based on figures produced by the University of Otago, the Herald has calculated how much water vapour a family of four produces through daily activities in their home.

Four people breathing actively for 14 hours can produce around 11 litres of water a day or 0.2 litres an hour per person.

Drying clothes inside can add 5 litres of moisture per load, compared to 0.5 litres for washing one load of clothes.

Cooking can add up to 3 litres a day and experts recommend using pan lids to contain steam and fans that vent outside the house where possible to reduce that amount.

Showers and baths produce 1.5 litres per person per day. Using an extractor fan when showering or opening a window can greatly reduce this figure.

One person spending an average of 14 hours (including sleep) at home will produce 0.03 litres of sweat every hour.

Air with a higher level of moisture takes more energy to heat, which will increase the household energy bills or reduce your thermal comfort.

EECA Energywise states around 30 per cent of homes are damp and many houses in New Zealand have mould.

Homes exposed to very high levels of moisture can be more expensive to heat, causing respiratory problems, mould and fungus.

These sources of moisture are often hidden and can go undetected for a long time, causing damage to your home.

EECA Energywise senior technical adviser Christian Hoerning says finding the source of dampness and fixing it is the best approach.

"First check if your home is showing signs of excess moisture and dampness then fix the problem directly.

"Check underneath your home - especially if you have a suspended timber frame - for dampness or water pooling under your house and fix any guttering, downpipe or plumbing problems.

"We would not recommend using unflued gas heaters as they release toxic gases which are not good for your health, and a lot of moisture.

"If you are looking to dry out a room or a home, use a plug-in electric heater because it is safer and cheaper to run."

Symptoms to look out for are musty smells in rooms that are closed for any period of time, damp or mould under your house and stains or watermarks on ceilings or walls.

Consumer NZ writer Paul Smith said: "To reduce dampness, you can use extractor fans or open a window while showering.

"Using pot lids and a rangehood when cooking, and drying clothes outside on a good day, or with a vented dryer - these small changes can save 8 litres or more entering your house each day," Smith said.

"Remember that dampness, and the mould it causes, isn't just unhealthy, it costs more to heat damp air.

"We've found the best dehumidifiers extract up to 6 litres of moisture per day at 12C, but much less when it is colder. They'll help, but won't be a silver bullet for a damp home."