Roof Ventilation Theory

Roof and attic ventilation provisions can actually promote roof warming if they are open to the interior conditioned space s.

Roof ventilation theory.

There are traditionally four main reasons for venting a roof. A passive roof ventilation system which has openings low and high is designed to move air in an unconditioned space using the natural flow of air called stack effect. In mixed climates ventilation serves either role depending on the season. Exterior wind and interior stack effect building pressures tend to force warm interior air into the ventilation spaces exacerbating roof warming.

Controlling ice damming by keeping the roof cold. Theory behind venting ice dams form when a home s escaping heat warms the roof sheathing and melts the underside of the snow layer on the roof. The intent of roof venting varies depending on climate but it is the same if you re venting the entire attic or if you re venting only the roof deck. Roof ventiliation explained for australian homeowners by john breeze of northern rivers insulation.

Enhancing roofing material life span by reducing sheathing temperature.