At first glance any discussion about attic ventilation seems a) out of place in a roofing blog and b) sounds crazy when the major concern with attic insulation is to keep heat in the house!
Let’s deal with the latter first. In the winter a well-ventilated roof actually helps to keep the attic cold which is a good thing! A cold attic prevents ice damming where snow melts off the roof (because the attic is warm) only to re-freeze when it reaches the gutter which is really cold. When the attic is a similar temperature to the outside world this melting and refreezing doesn’t happen. In the summer proper ventilation moves that really hot air out of the attic protecting your roof from excessive internal heat. This excessive heat can lead to premature aging and cracking of roof shingles and warping and cracking of the wooden frame.
The second part of that explanation starts to explain how proper attic ventilation affects roofs and how they are actually an integral part of a roofing system.
Ridge vents as shown here are the most popular and probably the most recommended ventilation system. They are relatively inexpensive and require little-or-no maintenance once installed. Power fans are also acceptable as long as they are installed with both a thermostat and humidistat. Power fans for ventilation are typically a more expensive option.
Whether you use ridge vents or power fans, neither will work correctly if the proper intake, or soffit, venting isn’t done. One common mistake by homeowners is that they put insulation inside their attic so that covers the soffit vents thinking they are keeping their attic better sealed. In fact the soffits are on the outside of the house so covering them with insulation a) doesn’t affect the sealing of the attic and b) severely reduces the amount of ventilation in and through the attic (leading to the problems described above).
Not sure about the ventilation in your attic? We’d be happy to come out a take a look for you – call George J Keller & Sons today at 973-927-0963 and we’ll discuss your options with you.