BASC Search

Ventilation air inlets ≥ 2 ft. above grade or roof deck in Climate Zones 1-3 or ≥ 4 ft. above grade or roof deck in Climate Zones 4-8 and not obstructed

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.

Ventilation inlet does not terminate high enough above the roof deck

Unvented Conditioned Attic with Spray Foam Insulation Below Roof Deck

Guide describing a method for insulating an unvented attic by spraying foam insulation along the underside of the roof deck.

Ventilation inlet is not near any exhaust outlets/contamination sources and is at least 2 ft. above the roof deck

Ventilation inlet is too close to exhaust outlets and does not extend at least 2 ft. above the roof deck

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

Retrofit an existing roof by installing rigid foam above the roof deck with a ventilation space between the rigid foam and the new roof sheathing plus new moisture and air control layers and cavity insulation in the roof rafters.

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.

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.

FORTIFIED Roof System - Hurricane

Publication Date

December, 2014

Animated video showing how to properly apply roof decks in hurricane regions according to IBHS practices.

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

Guide describing how to re-roof an existing home with a sloped and add insulation above the roof deck.

Air Sealing and Insulating Ceilings in Vented Attics

Guide describing how to air-seal and insulate a ceiling where the insulation is installed on top of the ceiling (on the attic floor) in a vented attic.

Ventilation Air Inlet Locations

Guide describing how to install ventilation air inlets in open locations at a safe distance from potential air contamination sources.

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.

Attic Eave Minimum Insulation

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

Spray Foam Insulation Applied to Existing Attic Floor

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

Design for Extreme Heat

Information guide describing ways to design a home to be resistant to extreme heat.

Home Performance Assessment

Information guide describing how to apply a whole-house approach to home improvement with energy efficiency upgrades, improved indoor air quality, and increased comfort.

Rigid Foam Board Interior Insulation for Existing Foundation Walls

Guide describing how to insulate closed crawlspace walls and band joist areas with rigid foam board insulation.

Aerosol Sealing Building Enclosures, Single and Multifamily Dwellings - Code Compliance Brief

Publication Date

January, 2020

The intent of this brief is to provide code-related information for aerosol sealing building enclosures to achieve durable air tightness levels that will be accepted as being in compliance with the code.

Ventilation air inlets ≥ 2 ft. above grade or roof deck in Climate Zones 1-3 or ≥ 4 ft. above grade or roof deck in Climate Zones 4-8 and not obstructed

Below Deck Spray Foam Insulation for Existing Roofs

Ventilation inlet does not terminate high enough above the roof deck

Unvented Conditioned Attic with Spray Foam Insulation Below Roof Deck

Ventilation inlet is not near any exhaust outlets/contamination sources and is at least 2 ft. above the roof deck

Ventilation inlet is too close to exhaust outlets and does not extend at least 2 ft. above the roof deck

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

Retrofit an existing roof by installing rigid foam above the roof deck with a ventilation space between the rigid foam and the new roof sheathing plus new moisture and air control layers and cavity insulation in the roof rafters.

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

Vented versus Unvented Attic

FORTIFIED Roof System - Hurricane

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

Air Sealing and Insulating Ceilings in Vented Attics

Ventilation Air Inlet Locations

Blown Insulation for Existing Vented Attic

Attic Eave Minimum Insulation

Spray Foam Insulation Applied to Existing Attic Floor

Design for Extreme Heat

Home Performance Assessment

Rigid Foam Board Interior Insulation for Existing Foundation Walls

Aerosol Sealing Building Enclosures, Single and Multifamily Dwellings - Code Compliance Brief

Attic Ventilation Fans

Pre-Retrofit Assessment of Existing HVAC Systems

Passive and Low-Energy Cooling