Attic ventilation is frequently misunderstood as a simple passive system, when in fact it requires careful fluid dynamic analysis to function correctly in Vermont's varied microclimates.
An improperly ventilated attic can reduce a roof system's service life by half, regardless of the quality of the roofing materials installed above.
The Net Free Area Equation
Building codes specify minimum net free ventilation area ratios, but Vermont's snow-prone climate demands a more sophisticated approach. Our designs calculate net free area based on roof pitch, orientation, local snowfall averages, and interior humidity loads. We specify high/low ventilation ratios that maintain continuous airflow even when soffit vents are partially obstructed by snow accumulation.
Ridge Vent Engineering
Modern ridge vent systems must resist wind-driven snow infiltration while maintaining exhaust capacity. We utilize baffled ridge vents with integrated weather filters that prevent snow ingress without restricting airflow. Combined with continuous soffit intake vents sized to match exhaust capacity, these systems create a uniform pressure plane that eliminates the hot spots and cold zones that lead to ice dam formation.
