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The ventilation space in this vented over-roof keeps the roof cool to prevent ice dams over the unvented attic

Publication Date

Tue, 09/01/2020 - 12:00

De-Icing Ice Dams, BSI-097

Author(s)

Lstiburek Joseph W

Organization(s)

Building Science Corporation,

BSC

Publication Date

October, 2018

Article describing the importance of air sealing, insulation, and roof ventilation in reducing the likelihood of ice dam formation on roofs in cold snowy climates.

Ice dams form when warmth from the attic causes roof snow to melt and flow to roof eaves where it refreezes at the colder overhang and forms a buildup of ice causing more snowmelt to puddle where it can wick back through shingles and leak into the attic

Publication Date

Sun, 11/01/2015 - 12:00

Unvented Attic Insulation

Guide describing methods for insulating an unvented attic along the roof line.

Construct Roofs and Attics for Ice Dam Prevention

Guide describing how ice dams form and how roofs can be constructed to prevent them.

Gutters and Downspouts

Guide describing the installation of gutters, downspouts, and alternate options for managing rainwater run-off from roofs.

Roof/Attic to Exterior Wall Air Control Upgrade

Guide outlining how to retrofit an exterior wall and/or attic to provide continuous air sealing.

Attic Air Sealing, Insulating, and Ventilating for Ice Dam Prevention

Information guide describing proper attic air-sealing, insulation, and ventilation to combat ice dam formation on roofs in cold climate zones.

Condensation Control in Attics and Roofs in Cold Weather

Guide describing causes of condensation in attics and roof assemblies during cold weather and ways to reduce this condensation.

Attic Eave Minimum Insulation

Guide providing guidance on insulating attic eaves in new and existing single-family homes and multifamily buildings.