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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.

Baffles allow ventilation under roof decking while keeping wind from blowing insulation back from the edges of an attic.

Publication Date

Thu, 09/01/2011 - 12:00

Right – Open-cell spray foam is installed over closed-cell spray foam in this hybrid approach to achieve adequate attic ventilation while allowing some vapor permeability.

Publication Date

Mon, 09/30/2019 - 12:00

Ceilings and Attics

Author(s)

Southface Energy Institute,

Oak Ridge National Laboratory

Organization(s)

ORNL,

SEI

Publication Date

February, 2000

Information sheet with information about insulating and ventilating attics.

Blown Insulation for Existing Vented Attic

Guide describing how to insulate a vented attic in an existing home using blown insulation added to the attic floor.

Vented versus Unvented Attic

Guide describing options for designing and locating the thermal boundary at either the attic floor or along the roof line in new and existing homes.

IRC FAQ: Conditioned Attics, GM-0905

Author(s)

Building Science Corporation

Organization(s)

BSC

Publication Date

May, 2009

Report discussing how to create livable space in the attic that meets IRC code requirements by either creating a ventilated roof assembly, or and unvented attic assembly.

Attic Eave Minimum Insulation

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

Right - The energy recovery ventilator ducts supply filtered outside air to multiple locations in the home and continuously exhaust stale air to provide clean, balanced ventilation.

Spray Foam Insulation Applied to Existing Attic Floor

Guide describing how to apply spray foam insulation to ceilings in existing homes.

How to Keep Attic Vent From Freezing Up in Winter

Publication Date

December, 2017

Author(s)

Tinsley

Organization(s)

Cold Climate Housing Research Center,

CCHRC

Video describing techniques to prevent attic plumbing vents from freezing during Alaskan winters.

Managing Indoor Humidity and Ventilation in Cold Weather

Guide describing steps to take to minimize indoor humidity in preparation for cold winter weather.

Right – Spray foam fills the roof joist cavities of this vaulted, unvented attic.

Publication Date

Thu, 09/30/2021 - 12:00

1 inch rigid insulation as attic eave baffle cut around manufactured vent

DWG

PDF

Conceptual insulation practice at attic-style truss system - above unconditioned space

DWG

PDF

Conceptual insulation practice at attic-style truss system - above conditioned space

DWG

PDF

The spray foam-insulated attic provides a temperate place for the ERV ducts, which provide filtered fresh air to every room in the house.

Below Deck Spray Foam Insulation for Existing Roofs

Guide describing how to add spray foam insulation to the underside of the existing roof deck as part of the conversion of a vented attic to an unvented, insulated attic.

Garage Rim/Band Joist Adjoining Conditioned Space

Publication Date

July, 2015

Video describing best practices for air sealing an attached garage during construction using plywood and spray foam in the band joist and providing an exhaust fan to ventilate and depressurize the attic.

Technology Solutions Case Study: Complete and Fully Aligned Air Barrier

Author(s)

Pacific Northwest National Laboratory

Organization(s)

PNNL

Publication Date

August, 2012

Case study describing the elimination of excessive humidity in the attic of a multi-floor, single-family home that was causing condensation and water damage along the roof and eaves.

Builders Challenge High Performance Builder Spotlight: David Weekley Homes, Houston, Texas

Author(s)

Pacific Northwest National Laboratory

Organization(s)

PNNL

Publication Date

December, 2009

Case study describing new home construction in the hot-humid climate, optimizing thermal enclosure, HVAC, water heating and lighting measures.

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

Baffles allow ventilation under roof decking while keeping wind from blowing insulation back from the edges of an attic.

Right – Open-cell spray foam is installed over closed-cell spray foam in this hybrid approach to achieve adequate attic ventilation while allowing some vapor permeability.

Ceilings and Attics

Blown Insulation for Existing Vented Attic

Vented versus Unvented Attic

IRC FAQ: Conditioned Attics, GM-0905

Attic Eave Minimum Insulation

Right - The energy recovery ventilator ducts supply filtered outside air to multiple locations in the home and continuously exhaust stale air to provide clean, balanced ventilation.

Spray Foam Insulation Applied to Existing Attic Floor

How to Keep Attic Vent From Freezing Up in Winter

Managing Indoor Humidity and Ventilation in Cold Weather

Right – Spray foam fills the roof joist cavities of this vaulted, unvented attic.

1 inch rigid insulation as attic eave baffle cut around manufactured vent

Conceptual insulation practice at attic-style truss system - above unconditioned space

Conceptual insulation practice at attic-style truss system - above conditioned space

The spray foam-insulated attic provides a temperate place for the ERV ducts, which provide filtered fresh air to every room in the house.

Below Deck Spray Foam Insulation for Existing Roofs

Garage Rim/Band Joist Adjoining Conditioned Space

Technology Solutions Case Study: Complete and Fully Aligned Air Barrier

Builders Challenge High Performance Builder Spotlight: David Weekley Homes, Houston, Texas

Home Performance Assessment

Water Managed Roof – Re-roofing and Adding Insulation Over a Sloped Roof

Sealed and Insulated Flex Ducts