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This concrete masonry unit (CMU) wall is insulated with rigid insulation on the exterior side of the concrete block

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This concrete masonry unit (CMU) wall is insulated with rigid insulation on the exterior side of the concrete block

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Rigid Insulation Over Aggregate

CAD File

Ducts Buried in Attic Insulation and Encapsulated

Guide

Guide describing approaches to burying and encapsulating ducts in unconditioned attics to increase the overall R-value of duct insulation.

Insulating a crawlspace foundation with “cripple wall” in warm climates; in Climate Zones 5+ replace the foil- or plastic-faced fiberglass batt/roll insulation with impermeable rigid insulation or closed-cell spray polyurethane foam

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No Vapor Retarders on Interior Side of Air-Permeable Foundation Insulation

Guide

Vapor retarder plastic should not be installed over fibrous insulation on basement or crawlspace walls; rigid foam or spray foam should be installed directly against the concrete, behind the blanket insulation.

High-Performance Slab-on-Grade Foundation Insulation Retrofits

Reference

Report assessing slab-on-grade foundation insulation energy savings.

Right – The basement of this cold-climate home is insulated along interior walls with 2 inches of foil-faced rigid foam; finished basement walls also have a 2x4 interior wall insulated with R-19 blown-in fiberglass insulation and a poly vapor barrier.

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Typical R-values and Vapor Retarder Classifications for Common Insulation Materials

Information Guide

Information guide providing R-Values and vapor retarder classifications for common insulation materials.

Vented crawlspace foundation insulated at floor joist with rigid foam.

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The below-grade wall assembly includes dampproofing, draining details, and insulation.

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Technology Solutions Case Study: Moisture Durability of Vapor Permeable Insulating Sheathing

Case Study

Case study describing research about using exterior, vapor permeable insulation of retrofit walls with vapor permeable cavity insulation.

Walls in cold climates with a polyethylene vapor barrier interior of the wall cavity should have either no exterior insulation or a vapor-open continuous insulation like mineral wool that allows drying to the exterior

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Right – Prepoured foundation panels with integrated insulation and vapor barrier are installed in place.

This house design in the Hot-Humid climate uses a slab foundation, masonry walls, and an Exterior Insulation Finish System (EIFS) cladding.

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Rigid foam insulation can serve as the drainage plane when all seams are taped. Furring strips provide an air gap behind the cladding.

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The Perfect Wall includes water, air, thermal, and vapor layers with continuous insulation exterior of the sheathing to reduce the condensation potential in the wall.

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Wrong - The fiberglass blanket insulation has no perforated vapor retarder, does not cover the entire basement wall, is not sealed at the edges, and is not installed over rigid foam.

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Vapor-permeable mineral wool insulation is installed on the exterior side of the sill beam during an exterior wall retrofit to allow the sill beam to dry to the outside

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Walls in cold climates with a Class 3 vapor retarder (latex paint) and a vapor-open continuous insulation like mineral wool allow drying to the interior or the exterior

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The floor of the sealed insulated crawlspace is covered with a heavy plastic vapor-barrier sheathing that is taped at all seams and around the foundation piers to prevent water vapor from moving into the crawlspace.

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Right - This crawlspace, which is insulated on the floor, has a complete vapor barrier over the floor and up the walls that is sealed at all seams and termite inspection gap at the top of the vapor retarder.

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Right – Workers lay radiant floor loops over the concrete reinforcement which is laid over a heavy vapor barrier installed over the sub-slab insulation before the slab is poured.

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When rigid foam insulation is applied to the exterior side of the wall cavity under the cladding, with seams taped and an air gap provided, it acts as a vapor barrier, air barrier, and rain screen.

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Masonry wall interior retrofit with parge coat, fluid-applied water control layer, rigid mineral wool, wood-framed wall with cavity insulation, smart vapor barrier, and wood or metal service cavity

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Horizontal furring strips are installed over a taped smart membrane that serves as an air and vapor barrier and holds in insulation; the furring strips will provide a nailing surface for tongue-and-groove wood porch ceiling cladding.

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This concrete masonry unit (CMU) wall is insulated with rigid insulation on the exterior side of the concrete block

This concrete masonry unit (CMU) wall is insulated with rigid insulation on the exterior side of the concrete block

Rigid Insulation Over Aggregate

Ducts Buried in Attic Insulation and Encapsulated

Insulating a crawlspace foundation with “cripple wall” in warm climates; in Climate Zones 5+ replace the foil- or plastic-faced fiberglass batt/roll insulation with impermeable rigid insulation or closed-cell spray polyurethane foam

No Vapor Retarders on Interior Side of Air-Permeable Foundation Insulation

High-Performance Slab-on-Grade Foundation Insulation Retrofits

Right – The basement of this cold-climate home is insulated along interior walls with 2 inches of foil-faced rigid foam; finished basement walls also have a 2x4 interior wall insulated with R-19 blown-in fiberglass insulation and a poly vapor barrier.

Typical R-values and Vapor Retarder Classifications for Common Insulation Materials

Vented crawlspace foundation insulated at floor joist with rigid foam.

The below-grade wall assembly includes dampproofing, draining details, and insulation.

Technology Solutions Case Study: Moisture Durability of Vapor Permeable Insulating Sheathing

Walls in cold climates with a polyethylene vapor barrier interior of the wall cavity should have either no exterior insulation or a vapor-open continuous insulation like mineral wool that allows drying to the exterior

Right – Prepoured foundation panels with integrated insulation and vapor barrier are installed in place.

Wrong - Duct insulation and vapor barrier do not cover all of the flex duct.

Right - This rigid insulation is correctly installed in a level layer over aggregate; the seams will be taped

Capillary Break Beneath Slab - Polyethylene Sheeting or Rigid Insulation over Aggregate or Sand and Geotextile Mat

The builder’s crews spray foam directly onto the ground to provide a vapor barrier and insulation layer under the slab.

This house design in the Hot-Humid climate uses a slab foundation, masonry walls, and an Exterior Insulation Finish System (EIFS) cladding.

Rigid foam insulation can serve as the drainage plane when all seams are taped. Furring strips provide an air gap behind the cladding.

The Perfect Wall includes water, air, thermal, and vapor layers with continuous insulation exterior of the sheathing to reduce the condensation potential in the wall.

Wrong - The fiberglass blanket insulation has no perforated vapor retarder, does not cover the entire basement wall, is not sealed at the edges, and is not installed over rigid foam.

Vapor-permeable mineral wool insulation is installed on the exterior side of the sill beam during an exterior wall retrofit to allow the sill beam to dry to the outside

Walls in cold climates with a Class 3 vapor retarder (latex paint) and a vapor-open continuous insulation like mineral wool allow drying to the interior or the exterior

The floor of the sealed insulated crawlspace is covered with a heavy plastic vapor-barrier sheathing that is taped at all seams and around the foundation piers to prevent water vapor from moving into the crawlspace.

Right - This crawlspace, which is insulated on the floor, has a complete vapor barrier over the floor and up the walls that is sealed at all seams and termite inspection gap at the top of the vapor retarder.

Right – Workers lay radiant floor loops over the concrete reinforcement which is laid over a heavy vapor barrier installed over the sub-slab insulation before the slab is poured.

When rigid foam insulation is applied to the exterior side of the wall cavity under the cladding, with seams taped and an air gap provided, it acts as a vapor barrier, air barrier, and rain screen.

Masonry wall interior retrofit with parge coat, fluid-applied water control layer, rigid mineral wool, wood-framed wall with cavity insulation, smart vapor barrier, and wood or metal service cavity

Horizontal furring strips are installed over a taped smart membrane that serves as an air and vapor barrier and holds in insulation; the furring strips will provide a nailing surface for tongue-and-groove wood porch ceiling cladding.