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Foundation wall exterior board insulation with above-grade wall insulation

CAD File

Moisture can migrate from below the foundation to the basement wall and insulation cavity in a conventional blanket insulation installation

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Wrong - Moisture from within the basement foundation wall can migrate into the insulation cavity in a conventional blanket insulation installation.

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Exterior XPS basement insulation is correctly installed to completely cover the foundation wall

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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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Masonry wall interior retrofit with fluid-applied water control layer and wood-framed wall with cavity insulation (climate zones 1-4 only)

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Construction Guide - Next Generation High Performance Walls in Climate Zones 3-5, Part II: 2x4 Walls with 1” - 1.5” Exterior Insulative Sheathing

Reference

The Guide addresses walls constructed with 2x4 wood frame studs, wood structural panel (WSP) sheathing as wall bracing and added backing for foam sheathing, a layer of rigid foam sheathing insulation up to 1.5 in. thick over the WSP, and a cladding system installed over the foam sheathing in low...

Right - This concrete basement wall has exterior rigid insulation and comprehensive moisture management details.

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Right - Section view showing how to air-seal and insulate a basement wall with perforated blanket insulation by installing it over air-sealed rigid insulation board to reduce condensation risk in the fiberglass blanket.

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Technology Solutions Case Study: Retrofit Measures for Embedded Wood Members in Insulated Mass Masonry Walls

Case Study

Case study describing retrofit measures for embedded wood members in insulated mass masonry walls.

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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In warm-humid climates, do not install Class 1 vapor retarders on the interior side of air-permeable insulation in above-grade walls, except at shower and tub walls.

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

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Because the above-grade potions of the wall lack exterior insulation, condensation and even ice form during cold winter conditions

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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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The builder in this very cold climate installed three layers of unfaced mineral wool batt in the double wall with a code-required vapor barrier between the middle and inner layers of wall insulation that is taped to barriers in the ceiling and floor.

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A paint-on waterproofing covers the exterior and tops of the concrete block foundation walls and piers to block moisture moving up through the concrete, while foil-faced R-13 insulation lines the inside surface of the exterior walls.

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Wrong - Air leakage from the conditioned space to the basement foundation wall can lead to condensation or moisture issues in a conventional blanket insulation installation.

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Exterior fiberglass insulation on this new home was (incorrectly) cut to terminate below-grade after backfill, which will expose the above-grade portions of the foundation wall to cold temperatures

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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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Wrong - Plastic-covered blanket insulation that is installed directly against concrete walls with no rigid foam or closed-cell spray foam covering the concrete could trap moisture coming through the concrete, leading to mold, moisture, and odor problems.

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Air Sealed, Insulated Basements

Guide

Guide describing how to insulate a basement to improve the overall thermal performance of the building and provide more dry, usable conditioned space for home occupants and HVAC equipment.

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.

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.

Vinyl Siding with Integrated Rigid Foam for Existing Walls

Guide

Guide describing the design and installation considerations for recladding of above grade walls using insulated vinyl siding.

Joni Mitchell, Water and Walls, BSI-071

Reference

Article describing walls and moisture development on them.

Flood-hardy, drainable, dryable wall

Video

Video explaining a design option for homes in the case of a flood that would negate the need for gutting the home post-flood. Recommendations from LSU AgCenter.

Moisture Performance of High-R Wall Systems

Reference

The next generation of building enclosures is a key step toward achieving high-performance goals through decreasing energy load demand and enabling advanced space-conditioning systems. Yet the adoption of high-R enclosures and particularly high-R walls has been a slow-growing trend because...

Affordable Solid Panel "Perfect Wall" System

Reference

Technical report describing the SPS (Structural Panel System), an innovative implementation of the "perfect wall" concept, situating environmental control layers on the exterior side of structural components for improved constructability, cost-effectiveness, and performance, validated through the...

To reduce the risk of condensation on the interior of the roof sheathing in cold weather, the ratio of exterior (above-deck) insulation must be increased as a percent of total attic insulation as outside temperature decreases

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