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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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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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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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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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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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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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Right – The raised slab foundation has a 3-ft stem wall of filled concrete block, then is back-filled with compacted dirt and crushed rock, then insulated with 1” rigid foam covered with taped vapor barrier, under a floor slab.

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Condensation Control for Walls in Cold Weather

Guide

Guide describing ways to construct wall assemblies in cold climates to minimize the likelihood of condensation formation inside the walls.

This exterior wall retrofit permits drying to the exterior of a sill plate installed on an untreated irregular foundation wall

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This exterior wall retrofit permits drying to the exterior of a sill plate installed on an untreated flat foundation wall

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Construction Guide - Next Generation High Performance Walls in Climate Zones 3-5, Part I: 2x6 Walls

Reference

Part I of the Guide addresses walls constructed with 2x6 wood frame studs, wood structural panel (WSP) sheathing as exterior sheathing, gypsum board as interior sheathing, and a cladding system installed over WSP sheathing in low-rise residential buildings up to three stories in height.

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.

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.

Wrong - Polyethylene sheeting should be lapped up sides of walls and pillars and taped

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Right-Polyethylene sheeting is correctly installed over aggregate and taped to pillars and foundation wall

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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 “institutional” perfect wall works in all climate zones; water, air, vapor, and thermal control layers are exterior of the sheathing, assembly allows drying to interior and exterior

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The Larsen-truss 9-inch wall cavities were covered with a smart vapor membrane that was fastened to the trusses with furring strips, which also provide an air gap behind the wood siding; each truss cavity is then filled with blown cellulose.

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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

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.

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

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

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

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.

Right – The raised slab foundation has a 3-ft stem wall of filled concrete block, then is back-filled with compacted dirt and crushed rock, then insulated with 1” rigid foam covered with taped vapor barrier, under a floor slab.

Condensation Control for Walls in Cold Weather

This exterior wall retrofit permits drying to the exterior of a sill plate installed on an untreated irregular foundation wall

This exterior wall retrofit permits drying to the exterior of a sill plate installed on an untreated flat foundation wall

Construction Guide - Next Generation High Performance Walls in Climate Zones 3-5, Part I: 2x6 Walls

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

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

Wrong - Polyethylene sheeting should be lapped up sides of walls and pillars and taped

Right-Polyethylene sheeting is correctly installed over aggregate and taped to pillars and foundation wall

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

The “institutional” perfect wall works in all climate zones; water, air, vapor, and thermal control layers are exterior of the sheathing, assembly allows drying to interior and exterior

The Larsen-truss 9-inch wall cavities were covered with a smart vapor membrane that was fastened to the trusses with furring strips, which also provide an air gap behind the wood siding; each truss cavity is then filled with blown cellulose.

Flow-Through Assemblies, BSI-091

Building Code Training - Residential Thermal Envelope - Air Sealing

2021 IBC and IRC Adopt Improved Vapor Retarder Requirements

Moisture Control for Residential Buildings