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Before sealing and insulating the crawlspace, the windows were sealed, the window wells backfilled, and sumps pumps were installed that discharged to the gutter downspouts

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Foil-faced rigid foam and spray foam can be used to insulate a basement on the interior; use good moisture management techniques to keep the basement dry

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Spray foam extends down the foundation wall to the slab, which has been retrofitted by adding dimple plastic drainage mat and rigid foam insulation.

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Right - Concrete masonry unit (CMU) basement wall showing exterior insulation and sill detail; above-grade wall has sheathing to the inside of the rigid foam.

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Exterior surface of below-grade walls finished as follows: For poured concrete, concrete masonry, and insulated concrete forms, finish with damp-proof coating

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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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Right – Two inches of rigid foam was installed on the ground before pouring the basement floor slab while precast, pre-insulated concrete panels comprise the basement walls.

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Water-proof materials cover the exterior side of crawlspace windows in a crawlspace retrofit, while foil-faced rigid foams seals and insulates the inside face of the openings

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Wrong - The basement blanket insulation is loosely attached to the interior of the basement wall, does not cover the entire wall, is not sealed at the edges, and is not installed over rigid foam that covers the entire surface of the foundation walls.

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Right – Foil-faced insulation was added after the crawlspace was dried and sealed by diverting water runoff, sealing off crawlspace windows and vents, and adding sump pumps and exhaust fan ventilation

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A dimpled plastic water barrier protects the insulated concrete form basement walls and carries any ground water down the walls to the footing drain to minimize the opportunity for water intrusion and frost heave.

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This basement is insulated on the exterior with rigid foam over dampproofing, with granular backfill and footing drains to facilitate drainage away from the foundation, a termite shield to protect from pests, and cellular PVC to protect the rigid foam.

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Right - Reduce condensation risks to blanket insulation by installing perforated vapor retarder covered fiberglass blankets over rigid foam that is air-sealed at all edges; staple the blanket to nailers and top/bottom plates and tape over the seams.

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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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Spray foam insulation extends down the foundation wall to the slab, which has been retrofitted by cutting the slab to install drainage mat against the wall and a new perimeter footing drain, along with rigid foam plastic above the slab.

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Floor Above Unconditioned Basement or Vented Crawlspace

Guide

Guide describing how to air-seal and insulate the floor above an unconditioned basement or crawl space.

ICF bricks are stacked to form hollow walls that are reinforced with steel rebar before the concrete is poured in

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Increase Seismic Resistance and Thermal Performance of Basement, Crawl Space, and Crawl Space with Cripple Wall Foundations

Guide

Guide describing different options for providing seismic and thermal resistance for homes with basement foundations, crawlspace foundations, or crawlspace foundations with a "cripple" wall.

Upgrading Below Grade Spaces

Presentation

Presentation describing basement insulation and potential problems.

Water Management of Existing Basement Floor

Guide

Guide describing how to retrofit an existing basement floor or slab to reduce moisture issues.

Water Management of Existing Crawlspace Floor

Guide

Guide providing information about treating bulk water drainage issues and moisture control measures in existing basements and crawl spaces.

Foundation Design Handbook

Reference

Handbook providing guidance on the design and construction of foundations for homes, including insulation, air sealing, and water management details for basements, crawlspaces, and slabs.

Upgrading Below Grade Spaces - Residential Energy Efficiency Stakeholder

Reference

Presentation describing the challenges of insulating an existing basement, presented to the Building America residential energy-efficiency stakeholder meeting.

Innovation in Frost Protected Shallow Foundations

Reference

Video describing how a frost-protected shallow foundation (FPSF) is constructed and including use of a stay-in-place EPS (expanded polystyrene) footing form that provides insulation and simplifies the installation of frost-protected monolithic concrete slab foundations.

Innovation in Frost Protected Shallow Foundations

Reference

Video describing how a frost-protected shallow foundation (FPSF) is constructed and including use of a stay-in-place EPS (expanded polystyrene) footing form that provides insulation and simplifies the installation of frost-protected monolithic concrete slab foundations.

Before sealing and insulating the crawlspace, the windows were sealed, the window wells backfilled, and sumps pumps were installed that discharged to the gutter downspouts

Foil-faced rigid foam and spray foam can be used to insulate a basement on the interior; use good moisture management techniques to keep the basement dry

Spray foam extends down the foundation wall to the slab, which has been retrofitted by adding dimple plastic drainage mat and rigid foam insulation.

Right - Concrete masonry unit (CMU) basement wall showing exterior insulation and sill detail; above-grade wall has sheathing to the inside of the rigid foam.

Exterior surface of below-grade walls finished as follows: For poured concrete, concrete masonry, and insulated concrete forms, finish with damp-proof coating

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

Right – Two inches of rigid foam was installed on the ground before pouring the basement floor slab while precast, pre-insulated concrete panels comprise the basement walls.

Water-proof materials cover the exterior side of crawlspace windows in a crawlspace retrofit, while foil-faced rigid foams seals and insulates the inside face of the openings

Wrong - The basement blanket insulation is loosely attached to the interior of the basement wall, does not cover the entire wall, is not sealed at the edges, and is not installed over rigid foam that covers the entire surface of the foundation walls.

Right – Foil-faced insulation was added after the crawlspace was dried and sealed by diverting water runoff, sealing off crawlspace windows and vents, and adding sump pumps and exhaust fan ventilation

A dimpled plastic water barrier protects the insulated concrete form basement walls and carries any ground water down the walls to the footing drain to minimize the opportunity for water intrusion and frost heave.

This basement is insulated on the exterior with rigid foam over dampproofing, with granular backfill and footing drains to facilitate drainage away from the foundation, a termite shield to protect from pests, and cellular PVC to protect the rigid foam.

Right - Reduce condensation risks to blanket insulation by installing perforated vapor retarder covered fiberglass blankets over rigid foam that is air-sealed at all edges; staple the blanket to nailers and top/bottom plates and tape over the seams.

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.

Spray foam insulation extends down the foundation wall to the slab, which has been retrofitted by cutting the slab to install drainage mat against the wall and a new perimeter footing drain, along with rigid foam plastic above the slab.

Floor Above Unconditioned Basement or Vented Crawlspace

ICF bricks are stacked to form hollow walls that are reinforced with steel rebar before the concrete is poured in

Increase Seismic Resistance and Thermal Performance of Basement, Crawl Space, and Crawl Space with Cripple Wall Foundations

Upgrading Below Grade Spaces

Water Management of Existing Basement Floor

Water Management of Existing Crawlspace Floor

Foundation Design Handbook

Upgrading Below Grade Spaces - Residential Energy Efficiency Stakeholder

Innovation in Frost Protected Shallow Foundations

Innovation in Frost Protected Shallow Foundations

DOE ZERH HIA 2017 Case Study: Thrive Home Builders, Courtyard Rows, Lone Tree, CO

Flood-Resistant Crawlspace Foundations

Right - Rigid foam board is attached to the interior surface of the basement walls.

Right - Closed-cell spray foam was applied to the interior of a foundation wall.

Right – Construction adhesive is applied to the rigid foam panels that will be installed on the interior basement walls.