Roof ventilation

Ridge vent  
Roof ventilation often involves drawing cool air in from under the eaves, and expelling warm air from the top of the roof.

Ventilation systems work to regulate heat and moisture in your home. A properly operating ventilation system will improve your home’s comfort, while also discouraging damp from setting in and causing damage. Likewise, effective ventilation also plays a role in ensuring that your home's climate control systems are as energy efficient as they can be.

 

The roof and ventilation

Without ventilation, hot, moist and stale air can become trapped in the roof cavity. During warmer months, this can cause heat to radiate through the ceiling and increase indoor temperatures.

In cooler months, moist air condenses and can encourage mould growth. Installing a ventilation system in the roof allows air to circulate, and can also help to improve the air quality in your home, allow moisture to evaporate, and control and regulate temperatures.

 

Roof mounted ventilation systems

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Correctly place roof vents will draw cool air into the roof, and expel warm air. Roof ventilation systems normally make use of two or more different types of vent to allow for a flow of air through the roof cavity and out of the top of the roof. Roof ventilation systems are normally either passive ventilation systems (as opposed to powered or mechanical systems), or are a combination of passive and mechanical vents.

Below is a list of the types of vents that might be used in a roof ventilation system:

  • Soffit vents - These are vents that can be installed in the underside of your eaves, also known as the 'soffits'. These vents draw air inside the roof, which then encourages the warmer air to be expelled, normally through a vent in the ridge of the roof.
  • Ridge vents - Ridge vents are installed along the ridge(s) of a pitched roof. They allow warm air to escape as it rises to the top of the house.
  • Whirlybirds - Also known as turbine vents, whirlybirds also help heat to escape from the roof cavity. These vents are situated on top of the roof. Theys have fins which help them to spin, which creates a vacuum, drawing hot air up and out of the roof cavity.
  • Whole house fans - Whole house fans, whilst not that common in Australia, can be installed to draw hot air out of the living area of your house and up into the ceiling cavity. They are usually located on the the ceiling of the most central room in the house. Because whole house fans work by drawing cool air inside the house, the outdoor temperature needs to be lower than indoor temperature for these to be effective.
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