Cold Deck Roof Ventilation

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.

Cold deck roof ventilation.

Adding attic ventilation can help but the real problem is heated air leaking up into the attic. Ventilation is required to the underside of the deck. No ventilation is required for these types of roofs. Melting snow then backs up behind these dams causing leaks into the roofing material and into the interior of the home.

In cold climates poor roof ventilation can also cause the buildup of ice on roofs. The da 4 is an excellent solution for roofs with little or no overhang for the installation of traditional intake vents. 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. When placed below the structural deck.

This is caused by air leaking up from your home into the attic in the winter and condensing on the cold deck. 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. 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. See energy smart details in fhb 218 for more on ice dams.

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 deck air when properly installed with proper exhaust vents provides a balanced ventilation system to rid your attic space of trapped heat and moisture. Mold on the roof deck or rafters. In cold climates the primary purpose of attic or roof ventilation is to maintain a cold roof temperature to control ice dams created by melting snow and to vent moisture that moves from the conditioned space to the attic ventilation acts to bypass the vapour barrier created by most roof.

It is universally recommended that cold deck flat roof construction should be avoided.