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Conceptual insulation at cape-style roof - roof cavity insulation with rigid insulation closure

Conceptual insulation at cape-style roof - roof cavity insulation with rigid insulation closure

CAD File

Unvented Attic Insulation

Guide

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

Conceptual insulation at cape-style roof - ceiling and knee wall cavity insulation

Conceptual insulation at cape-style roof - ceiling and knee wall cavity insulation

CAD File

Failure in attic insulation effectiveness caused by wind washing pushing insulation away from the edges of the attic space.

Failure in attic insulation effectiveness caused by wind washing pushing insulation away from the edges of the attic space.

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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

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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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.

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

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

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Install an air barrier on the exterior of attic knee wall insulation.

Install an air barrier on the exterior of attic knee wall insulation.

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

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

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Right – Top and bottom plates were installed prior to backing and insulation.

Right – Top and bottom plates were installed prior to backing and insulation.

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Right – Rigid backing was installed prior to insulating the attic knee walls.

Right – Rigid backing was installed prior to insulating the attic knee walls.

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

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

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Wrong - Wind baffle installation will not allow insulation over the top plate.

Wrong - Wind baffle installation will not allow insulation over the top plate.

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The attic knee walls were constructed from 2x6s and insulated with R-19 batt, backed with 1 inch of XPS foam board with taped joints to provide a solid air barrier over the insulated surfaces.

The attic knee walls were constructed from 2x6s and insulated with R-19 batt, backed with 1 inch of XPS foam board with taped joints to provide a solid air barrier over the insulated surfaces.

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

CAD File

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

CAD File

A site-built rafter roof with a raised top plate allows for more insulation underneath.

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Limited attic access can make inspections for missing air barriers and insulation challenging

Limited attic access can make inspections for missing air barriers and insulation challenging

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Install a continuous air barrier below or above ceiling insulation and install wind baffles.

Install a continuous air barrier below or above ceiling insulation and install wind baffles.

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Right - Wind baffle installation will allow proper insulation depth over the top plate.

Right - Wind baffle installation will allow proper insulation depth over the top plate.

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Cost Analysis of Roof-Only Air Sealing and Insulation Strategies on 1 1/2-Story Homes in Cold Climates

Reference

Report exploring alternative methods to find long-term solutions to energy loss in 1 ½-story homes to save energy, improve comfort, prevent frost buildup on the underside of the roof deck, and reduce the risk of ice dam formation/reformation.

The soffit dam and baffle allow air to flow through the vents without disturbing the insulation covering the top plates

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

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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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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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.

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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There are three potential locations for an attic radiant barrier – adhered to the underside of the roof decking, hanging from the rafters, or on the ceiling insulation

There are three potential locations for an attic radiant barrier – adhered to the underside of the roof decking, hanging from the rafters, or on the ceiling insulation

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Limited attic access may make it necessary to use a bore scope when inspecting for missing air barriers and insulation in existing buildings.

Limited attic access may make it necessary to use a bore scope when inspecting for missing air barriers and insulation in existing buildings.

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

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

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Right - These attic knee walls are insulated with rigid foam and sealed with spray foam to form a continuous air barrier at the gable end of this cathedral ceiling.

Right - These attic knee walls are insulated with rigid foam and sealed with spray foam to form a continuous air barrier at the gable end of this cathedral ceiling.

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Baffles provide an air space over the insulation to guide ventilation air from the soffit vents up along the underside of the roof deck

Baffles provide an air space over the insulation to guide ventilation air from the soffit vents up along the underside of the roof deck

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