The Ins and Outs of Roofing Ventilation
Whether you've just moved into a new home, you've noticed your home's a bit cold, or you've started to notice that your attic is more humid than it should be, it's time to look into replacing or repairing your roof ventilation system. Keeping up with roofing maintenance is extremely important, especially in areas with heavy winters or high precipitation. Ventilation is one of the most important preventative measures to guard against leaks and cave-ins.
What Does Ventilation Do?
Roofing ventilation pulls good, fresh air in from outside and cycles moisture and humidity out. It regulates the air in your attic so that the temperature consistently matches the temperature outside. If the attic gets too warm or humid, a number of dangerous scenarios can occur. Thanks to humidity, mould and mildew thrive, metal struts or brackets rust, and wood rots and warps. The entire roofing structure can sag and weaken if the humidity levels get too high, which can lead to leaks, cave-ins, and expensive repairs.
How Can I Tell if my Ventilation Needs to Be Replaced?
Even if you have no roofing experience, here are a few warning signs that may indicate the need to have your ventilation inspected:
- Your roof has no external vents at all
- Your attic feels more humid than it should
- Your ceiling is warm to the touch on a hot, sunny day
- Your eaves collect thick ridges of ice in the winter
- You see frost or condensation in your attic
- You find mildew or mould in your attic or under the eaves
- You have not replaced or upgraded the insulation in your attic for some time
- Your exterior paint peels or blisters
What Kind of Ventilation Do I Need?
Every roof needs ventilation, but there are several different varieties from which to choose. On every roof, both low (soffit) and high vents should be installed – the high vents act as exhaust vents, the lower act as intake vents. There are 4 different types of exhaust vents: ridge, turbine, box, or powered. Only one type should be installed per roof.
One caveat regarding turbine vents: They should not be used if your attic has not been professionally air-sealed. Turbine vents pull air from the attic, and if the attic has not been sealed it will draw air from inside the house instead. This will put an extra strain on your air conditioning and heating, and your cooling and heating bills will rise substantially.