Without proper attic ventilation, your attic is susceptible to condensation and heat build-up.
Both these conditions can wreak havoc in your attic, your shingles and the inside of your house.
The primary reason for proper ventilation is two-fold.
In the summer, proper ventilation allows hot air convection through the roof vents.
The purpose of releasing the hot air is so the attic does not build up too much heat.
The intense attic heat prematurely ages your shingles.
It also causes your house to get a lot hotter and makes your air conditioning work that much harder to keep your house cool.
In the winter, ventilating ensures that air flows from the intake grills in the soffits, through the attic and out the attic vents at the roof peak.
In this case, it is of primary important that adequate attic insulation is in place.
With proper insulation and great air flow, the possibility of condensation build-up dissipates and condensation and mold does not have a chance to develop.
Ensuring ventilation is working properly is one of the most misunderstood “systems” in the house.
I have regularly encountered poor ventilation and insulation resulting in rotted roof sheathing and trusses, premature aging of shingles and damaged insulation.