Good ventilation, an intelligent choice for your roof

Good ventilation, an intelligent choice for your roof

Why ventilate the attic of your home?

Not only do you minimize your heating and cooling costs, but you also meet a requirement of the building code and roofing material manufacturers. The problems caused by poor ventilation are numerous and constitute one of the significant factors of premature roof wear. In addition, it could have a negative impact on your roofing warranty. A conscientious and competent roofer will therefore pay particular attention to this.

 

Year-round energy savings

Good ventilation allows you to keep the heat inside the house during the winter, while in the summer, you will avoid heat accumulation in the attic.

 

Consequences of poor ventilation in summer

Excessive heat in the attic will have an immediate impact on the residents. According to the National Building Code, an hourly change of fresh air in the attic is necessary to avoid a greenhouse effect that will increase the interior temperature of the attic significantly. Since this overheating is often combined with poor insulation, it will be transmitted to the floor below through the ceiling. It will force you to keep the air conditioning on more regularly and for more extended periods.

Results

  • Additional costs related to air conditioner maintenance and energy consumption.
  • Premature wear and tear on the air conditioning system.
  • Damage to your roof.

Overheating of materials causes premature deterioration. For flat roofs, installing a white membrane reduces this phenomenon because it absorbs less heat than a darker membrane.

 

Consequences of poor ventilation in winter

A warm attic in winter will melt some of the snow on the roof. You will then notice ice dams forming where heat loss is less, such as on ledges or opposite uninsulated and unheated carports. The formation of large icicles is also a sign to watch. If there is a rainstorm or a late snowmelt, the ice on your roof will prevent water from draining freely. The direct consequences of this poor drainage are the risk of water infiltration through the top.

In addition, warm air carries moisture which, when in contact with cold air, will become liquid or solid (ice, frost). In the house, we use the shower, the dishwasher, and the washing machine; this influences the variation of the humidity level. The condensation created by the humidity will eventually negatively impact the frame and the insulation by forming mold, ice dams, etc. Also note that wet insulation is much less effective, if not ineffective, in this situation. It’s like deciding to wear wet clothes. Once soaked, the best winter coat would not be able to keep you warm properly and would even contribute to your heat loss.

 

A few rules

  • Keep the attic temperature cooler or at the same level as the outside temperature with a proper roof ventilator. There are two types of ventilators:
    1. The static fan: acts like a chimney pulling warm air to the outside. The static fan with the turbine is optional since the motor turns only to avoid water or snow infiltration.
    2. The passive ventilator: is only a standard air intake, a hole covered with a grid.
  • Insulate heating ducts, recessed lighting fixtures, and fans to avoid increasing the heat in the attic.
  • Check roof vents and soffits and make sure they are not blocked.
  • Do not send return air from the range hood, clothes dryer, or bathroom ventilation into the soffits. These are used to ventilate the roof. If you send heat and moisture back into the soffits, it will be redirected directly into the attic, negating the intended effect.

A mansard roof will not require the same type of ventilation as a flat roof. That’s why each house should be evaluated on a specific basis. At Toiture Union, we can help you determine your ventilation needs. Contact us for a free estimate.

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