Roof Ventilation Theory

Enhancing roofing material life span by reducing sheathing temperature.

Roof ventilation theory.

In mixed climates ventilation serves either role depending on the season. 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 ventilation is one of the systems that performs best when air sealing has been properly completed.

In a hot climate the primary purpose of ventilation is to expel solar heated hot air from the attic or roof to reduce the building s cooling load and to relieve the strain on air conditioning systems. Exterior wind and interior stack effect building pressures tend to force warm interior air into the ventilation spaces exacerbating roof warming. There are traditionally four main reasons for venting a roof. Roof ventiliation explained for australian homeowners by john breeze of northern rivers insulation.

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