Cold Deck Roof Ventilation

This video shows the key features of a flat roof cold deck construction and how to draw the details to a scale of 1 10.

Cold deck roof ventilation.

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 deck air when properly installed with proper exhaust vents provides a balanced ventilation system to rid your attic space of trapped heat and moisture. This is caused by air leaking up from your home into the attic in the winter and condensing on the cold deck. In cold climates poor roof ventilation can also cause the buildup of ice on roofs.

Cold deck roof a cold deck roof is where the insulation is placed between the joists rafters or in between the ceiling joists in the case of a. 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. Ventilation is required to the underside of the deck. 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.

Mold on the roof deck or rafters. Ice dams can cause thousands of dollars of damage to roofs and interior building materials. Adding attic ventilation can help but the real problem is heated air leaking up into the attic. See energy smart details in fhb 218 for more on ice dams.

When placed below the structural deck. The da 4 is an excellent solution for roofs with little or no overhang for the installation of traditional intake vents. No ventilation is required for these types of roofs. This cold deck construction is considered problematic in the humid temperate climate of the uk where the effective ventilation of restricted roof voids may be impractical particularly in sheltered built up areas.

Throughout the balance of this digest the terms attic and roof will and can be used interchangeably.