Does roof ventilation work? This is a question that many homeowners ask, seeing as it is roof ventilation is commonly found on commercial buildings. The most common residential ventilation is the ‘Whirlybird’ roof ventilation system which works by evacuating hot air. While the roofing ventilation technology has improved to include powered ventilation, the efficiency of residential roof ventilators is still debatable.

  • Non-powered roof ventilation systems are unable to handle high loads and is inefficient in moving large volumes quickly
  • Roof ventilators that are fed air from the inside the house end up  creating a pressure deficit that pulls in hot air from the outside through doors and windows, negating the whole cooling effect and placing a higher load on the system instead
  • Air vents that connect to a whirlybird on the roof must be opened and closed several times in a year. This involves climbing ladders and working at heights which is risky
  • Ventilation in high moisture areas like the kitchen and bathroom does not evacuate all the moisture laden air which may encourage mold growth in cavities
  • Humidity is a problem even for well ventilated houses. A ventilated house without adequate insulation will suffer moisture problems as the humid air condenses as the air cools.  Insulation plus good placement of exhaust fans would be more efficient in controlling the moisture.
  • Roof ventilation is susceptible to infiltration by dust and other contaminants like pollen. This could bring up problems for people suffering respiratory allergies.


Insulation works by making parts of the house more resistant to heat transfer. Attic insulation prevents heat transfer from the roof. When the roof is hot, the air in the rooms below remains cool as the insulation material prevents heating through radiation.

Insulation also works in the cold season by preventing heat loss by conductivity through the housing structure materials. The temperature in the building remains stable and comfortable, reducing the need for heating or cooling.

Insulation works better than ventilation because it uses air tightness rather than moving different air masses in and out of the building. By maintaining air tightness, air temperature fluctuation is minimal which means temperature control systems in the house work less hard.

Ridge venting coupled with insulation works better in controlling condensation and moisture in the house.

Installation and maintenance

It is good to note that insulation does not involve moving parts like fans, which must be powered. There are easier insulation methods like Spray foam insulation which is basically”shooting”  insulation material into the space to be insulated.

Be sure to use a ventilation and insulation professional, as they will help determine the right system for your home and your needs.

Are you looking to make your home more energy efficient? Contact 4 Weather Insulation and Roofing for free consultation.

Contact 4Weather

Get in touch with the team at 4Weather for any of your ventilation, insulation, & roofing needs. We will get back to you as soon as possible. Thank you for contacting 4Weather!