BASC Search

Air Sealing Drywall to Top Plate

Guide

Guide describing ways to seal drywall to the top plate of an exterior wall to air-seal the wall cavity.

Air Sealing Duct and Flue Shafts

Guide

Guide describing how to air-seal duct and flue shafts.

Wrong – Seams of air barrier not sealed

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Wrong – Seams of air barrier not sealed

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Air Sealing Bathroom and Kitchen Exhaust Fans

Guide

Guide describing how to air-seal bathroom and kitchen exhaust fans.

Air seal the attic access panel with weatherstripping.

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Air Sealing and Insulating Ceilings in Vented Attics

Guide

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.

Air Sealing Attic Access Panels/Doors/Stairs

Guide

Guide describing how to air-seal attic access panels, doors, and stairs to provide a continuous air barrier at the ceiling.

Air-seal the attic kneewall door opening with weatherstripping.

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Air seal attic access panels and drop-down stairs to minimize air leakage.

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Right – Seams and penetrations of air barrier properly sealed

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Right – The knee wall is properly insulated and air sealed.

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Air seal and insulate drawer and closet boxes in attic kneewalls

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Right – The backing on this knee wall was air sealed prior to insulation.

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Air seal the attic access pull-down stairs opening with weatherstripping.

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Building Science for Dry Climates 5 - Building Shell, Air Sealing, & Attics

Presentation

Presentation by Home Performance Contractor Academy giving building science advice for for homes in dry climate zones, specifically building envelope, air sealing, and attics. Part 5 of 7.

Wrong – The backing on this knee wall was not air sealed prior to adding insulation.

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Wrong – The batt insulation on this knee wall is not properly supported and there is no air sealed rigid backing to provide a solid air barrier.

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After all holes through the ceiling are air-sealed and the baffles have been installed, then the insulation can be installed.

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Right-- IR photo shows how effectively spray foam insulated/air sealed attic kneewall and the floor cavities under kneewall

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Technology Solutions Case Study: Complete and Fully Aligned Air Barrier

Case Study

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.

Right – This attic knee wall and the floor joist cavity openings beneath it are being sealed and insulated with spray foam.

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The attic kneewall and the open floor cavities under kneewall are both sealed and insulated in one step with spray foam insulation

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This kneewall has no top plate and the resulting gap provides a wide-open pathway for air and vapor to travel between the living space and the attic

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Air Sealing Drywall to Top Plate

Air Sealing Duct and Flue Shafts

Wrong – Seams of air barrier not sealed

Wrong – Seams of air barrier not sealed

Air Sealing Bathroom and Kitchen Exhaust Fans

Air seal the attic access panel with weatherstripping.

Air Sealing and Insulating Ceilings in Vented Attics

Air Sealing Attic Access Panels/Doors/Stairs

Air-seal the attic kneewall door opening with weatherstripping.

Air seal attic access panels and drop-down stairs to minimize air leakage.

Right – Seams and penetrations of air barrier properly sealed

Right – The knee wall is properly insulated and air sealed.

Air seal and insulate drawer and closet boxes in attic kneewalls

Right – The backing on this knee wall was air sealed prior to insulation.

Air seal the attic access pull-down stairs opening with weatherstripping.

Building Science for Dry Climates 5 - Building Shell, Air Sealing, & Attics

Wrong – The backing on this knee wall was not air sealed prior to adding insulation.

Wrong – The batt insulation on this knee wall is not properly supported and there is no air sealed rigid backing to provide a solid air barrier.

After all holes through the ceiling are air-sealed and the baffles have been installed, then the insulation can be installed.

Right-- IR photo shows how effectively spray foam insulated/air sealed attic kneewall and the floor cavities under kneewall

Technology Solutions Case Study: Complete and Fully Aligned Air Barrier

Right – This attic knee wall and the floor joist cavity openings beneath it are being sealed and insulated with spray foam.

The attic kneewall and the open floor cavities under kneewall are both sealed and insulated in one step with spray foam insulation

This kneewall has no top plate and the resulting gap provides a wide-open pathway for air and vapor to travel between the living space and the attic

Attic Knee Walls

Ducts in Raised Ceiling Sections

Blown Insulation for Existing Vented Attic

Batt Insulation for Existing Vented Attics

Spray Foam Insulation Applied to Existing Attic Floor

Pre-Retrofit Assessment of Attics, Ceilings, and Roofs