Northern Climate Roof Venting

In areas subject to.

Northern climate roof venting.

Our field measurements and computer modeling show that without attic venting the temperature of the underside of the roof sheathing increases by 10 f 20 f. In a cold climate the primary purpose of ventilation is to maintain a cold roof temperature to avoid ice dams created by melting snow and to vent any moisture that moves from the conditioned living space to the attic. The building codes and building science for natural roof ventilation however only appeared in the 1940s. Warming up to unvented roofs the underside of the roof sheathing is where the real benefits of not venting roof assemblies are found.

In coastal climates wind driven rain can be blown in through these openings with similar results. Unventing attics in cold climates saves. This comprehensive collection of articles and videos on roof venting will help you throughout every step of the process whether you re still weighing the options or are beginning installation. Roof ventilation in a cold climate vents moisture and ensures a cold roof temperature to avoid ice dams.

That answers the energy question. 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. In cold northern climates snow can be blown in through these openings accumulating melting and causing damage to the ceiling or creating the potential premature structural failure or mold growth inside the roof assembly. In cold climates this is an advantage.

Unventing roof assemblies in most cold climates decreases the heating load by about 10. This â atticâ space was typically vented via static air vents. The roof design included an interstial space of 1 5 to 2 meters between the ceiling and roof deck. The roofing was typically asphalt or coal tar built up roofing applied directly to the roof deck.