BASC Search | Building America Solution Center

Flood-Resistant Raised-Slab Foundations

Guide describing ways to construct a raised-slab foundation to increase a home's resistance to floods.

Structural Foundation Slab | Madrona Passive House

Publication Date

October, 2014

Video explaining the structural foundation slab in a passive house.

Exterior Edge Insulation for Existing Foundation Slabs

Guide describing how to install slab edge insulation when retrofitting existing slab-on-grade foundations.

Drainage techniques for slab-on-grade foundations

Publication Date

Tue, 01/01/2013 - 12:00

Caulk the seam between the slab and foundation wall

Rigid foam wraps the exterior of the foundation slab.

In cold climates, install slab edge insulation when pouring slab on grade foundations.

Seismic and Thermal Resistance in Slab-on-Grade Foundations with Turned-Down Footings (Monolithic Slabs)

Guide describing how to construct and retrofit homes built on slab-on-grade foundations in earthquake-prone areas to withstand seismic forces by properly installing wall to foundation connections.

Assembly Sequence for Slab-on-Grade Foundation with Concrete Stem Wall and Under Slab Insulation

Publication Date

January, 2013

Author(s)

University of Minnesota

Organization(s)

ORNL,

Oak Ridge National Laboratory,

University of Minnesota

Video animation showing an assembly sequence for slab-on-grade foundation with stem wall and under slab insulation.

High-Performance Slab-on-Grade Foundation Insulation Retrofits

Author(s)

Goldberg Louise F,

Mosiman Garrett

Organization(s)

NorthernSTAR,

NSTAR,

University of Minnesota,

UMN

Publication Date

September, 2015

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

A raised slab foundation elevates the level of the floor above grade

Publication Date

Wed, 08/10/2022 - 12:00

Rigid Foam Insulation Installed over Existing Foundation Slabs

Guide describing how to insulate an existing slab floor by adding rigid foam insulation over the slab then installing a floating subfloor.

This raised-slab CMU and brick foundation includes flood-resistant features such as a sloped grade, capillary break under the slab (gravel or sand), vapor barrier under the slab (polyethylene sheet), and capillary break at the top of the foundation wall

Publication Date

Sat, 01/01/2022 - 12:00

This raised-slab poured concrete foundation includes flood-resistant features such as a sloped grade, capillary break under the slab (gravel or sand), vapor retarder under the slab (rigid insulation), and capillary break at the top of the foundation wall

Publication Date

Sat, 01/01/2022 - 12:00

Structural system components of slab-on-grade foundation with grade beam

Publication Date

Tue, 01/01/2013 - 12:00

Right – The seam between the slab and the foundation wall is sealed with urethane caulk.

The home’s slab-on-grade foundation is wrapped in a blanket of rigid foam extending completely under the slab and along the edges.

Raised-slab CMU foundation including flood-resistant features: sloped grade, damp proofed stem wall, capillary break under the slab (gravel or sand), vapor barrier under the slab and capillary break at the top of the foundation wall (polyethylene sheet)

Publication Date

Sat, 01/01/2022 - 12:00

A common method of addressing significant groundwater leakage in the foundation is to line the entire foundation assembly, including the slab, with a drainage layer.

Publication Date

Tue, 09/17/2024 - 12:00

Externally insulated concrete slab-on-grade foundation with a turn-down footing, showing anchorage of the wall to the foundation for seismic resistance

To help keep the monolithic slab-on-grade foundation dry, the site’s surfaces is graded away from the structure, the slab is poured on a bed of gravel, and using a vapor barrier will separate the foundation from the sill plates.

Reinforce concrete slab and foundation walls to minimize future cracks that could let in pests

Rigid foam extends under the full slab and lines the inside edges of the foundation walls.

Assembly Sequence for Slab-on-Grade Foundation with Integral Grade Beam and Exterior Insulation

Publication Date

January, 2013

Author(s)

University of Minnesota

Organization(s)

ORNL,

Oak Ridge National Laboratory,

University of Minnesota

Video animation showing an assembly sequence for slab-on-grade foundation with integral grade beam and exterior insulation.

Right - Rigid foam insulation is installed along the exterior edge of an existing foundation slab.

Right - Additional potential locations for slab-on-grade insulation include (a) under the slab and outside the perimeter with optional underground moisture block, (b) under the whole foundation, or (c) on top of the slab.

Publication Date

Tue, 01/01/2013 - 12:00

Concrete slab-on-grade foundation with a turn-down footing insulated on its top surface, showing anchorage of the wall to the foundation for seismic resistance

Publication Date

Tue, 08/24/2021 - 12:00

Assembly can be used in IECC CZ 3 and above to thermally isolate garages in multifamily row houses with slab foundations. For unheated garages, it is unnecessary to insulate wall between garage and exterior of slab or slab underneath garage.

Publication Date

Sat, 09/14/2024 - 12:00

Externally insulated post-tensioned concrete slab-on-grade foundation wall with a turn-down footing showing anchorage of the wall to the foundation for seismic resistance

Publication Date

Tue, 08/24/2021 - 12:00

Externally insulated post-tensioned concrete slab-on-grade foundation wall with a turn-down footing showing anchorage of the wall to the foundation for seismic resistance

Publication Date

Tue, 08/24/2021 - 12:00

Technology Solutions Case Study: Exterior Rigid Foam Insulation at the Edge of a Slab Foundation, Fresno, California

Author(s)

IBACOS

Organization(s)

IBACOS

Publication Date

October, 2013

Case study describing installation of exterior rigid foam insulation on a slab foundation.

Right - The slab-on-grade foundation is insulated with two layers (R-20) of XPS foam under the-slab and R-10 on the exterior of the stem walls.

Publication Date

Thu, 09/30/2021 - 12:00

Right – Rigid foam was attached to the tops of the precast foundation walls to form an insulated edge for the floor slab.

Publication Date

Mon, 09/30/2019 - 12:00

ICF foundation walls wrap the floor slab in R-22 of insulation while the entire space under the slab is covered with 4.3 inches of closed-cell spray foam.

Right - Flood resistant slab and crawlspace foundations elevate the floor above the design flood elevation.

Publication Date

Wed, 12/01/2010 - 12:00

Spray foam extends down the inside of the foundation wall to the uninsulated slab; because the wall lacked exterior perimeter drainage, the slab was cut and an interior footing drain was installed.

Publication Date

Mon, 07/01/2013 - 12:00

Basic foundation types: deep basement, submerged crawl space, flush crawl space, and slab-on-grade

Publication Date

Tue, 01/01/2013 - 12:00

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.

Publication Date

Mon, 07/01/2013 - 12:00

Right – Insulated concrete forms (ICFs) provide the insulated stem wall for the slab-on-grade foundation for this SIP house.

Publication Date

Thu, 09/30/2021 - 12:00

Brick veneer framed wall supported by a concrete slab-on-grade foundation with a turn-down footing insulated on its top surface, showing anchorage of the wall to the foundation for seismic resistance

Publication Date

Tue, 08/24/2021 - 12:00

This Texas homes uses a slab foundation including a 4-in.-thick post-tensioned monolithic slab with turned-down edges poured over a 6-mil polyethylene vapor barrier and capillary break; slab edge insulation is not used due to termite risk.

Publication Date

Thu, 09/01/2011 - 12:00

The goal of foundation moisture management is to construct the basement, crawlspace, or slab in a way that keeps moisture from getting in in the first place

Publication Date

Thu, 03/01/2012 - 12:00

A concrete slab-on-grade foundation with exterior insulation, which can be elevated above the local grade as a flood-prevention strategy.

Publication Date

Tue, 01/01/2013 - 12:00

Spray foam and rigid foam were used under the slab while rigid foam wraps the exterior of the foundation walls.

Right – R-20 of XPS and polyiso rigid foam were added on the slab shelf that is part of this precast foundation wall system.

Publication Date

Mon, 09/30/2019 - 12:00

New Whole-House Solutions Case Study: Exterior Rigid Foam Insulation at the Edge of a Slab Foundation, Fresno, California

Author(s)

IBACOS

Organization(s)

IBACOS

Publication Date

October, 2013

Case study describing application of exterior rigid foam insulation on a foundation system.

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

Publication Date

Thu, 09/01/2011 - 12:00

FORTIFIED Home Eligibility Requirements—Foundations - Eligibility Requirements and Retrofit Requirements for Elevated-Floor (Not Slab-on-Grade) Houses

Author(s)

Insurance Institute for Business and Home Safety

Organization(s)

IBHS

Publication Date

April, 2017

Checklist intending to clarify FORTIFIED Home™ eligibility requirements that relate to a home’s foundation.

Any holes through the vapor barrier installed over the basement floor slab are thoroughly sealed as part of the foundation water barrier system.

Publication Date

Tue, 01/01/2013 - 12:00

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.

Publication Date

Mon, 09/30/2019 - 12:00

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

Publication Date

Mon, 07/01/2013 - 12:00

Right – After installing the insulated concrete foundation wall panels, the builder installed underslab rigid foam, which was topped by 4 inches of crushed rock then the poured slab.

Publication Date

Mon, 09/30/2019 - 12:00

This exterior insulated slab-on-grade monolithic grade beam foundation is protected from pests by termite shield at the sill plate, borate-treated framing, flashing at end of wall insulation, brick veneer over slab-edge insulation, and rock ground cover.

Publication Date

Mon, 03/01/2021 - 12:00

This left-to-right sequence shows the method of wall extension to flood-proof a masonry house on a slab foundation. Here the new, raised floor is wood-framed over a wet-floodproofed crawlspace, but using fill to create a new raised slab is also an option.

Publication Date

Wed, 01/01/2014 - 12:00

This assembly can be used to thermally isolate heated or partially heated garages with slab foundations from the exterior in multifamily row houses/townhouses in IECC Climate Zones 3 and higher.

Publication Date

Sat, 09/14/2024 - 12:00

Brick veneer is supported by a concrete stem wall thermally separated from the slab-on-grade foundation with turn-down footing which is also insulated on top; anchorage for seismic resistance is also shown

An externally insulated slab-on-grade is pest-protected by a metal termite shield under sill plate, metal-flashing-wrapped foam under siding, a removable inspection strip of PVC-covered foam, and 2 feet of gravel next to the foundation.

Publication Date

Mon, 03/01/2021 - 12:00

Slab-on-grade with concrete stem wall and slab insulation

Publication Date

Tue, 01/01/2013 - 12:00

Post-tensioned slab-on-grade with exterior and slab insulation

Publication Date

Tue, 01/01/2013 - 12:00

Slab-on-grade with integral grade beam and exterior and slab insulation

Publication Date

Tue, 01/01/2013 - 12:00

Slab-on-grade with masonry stem wall and interior and slab insulation

Publication Date

Tue, 01/01/2013 - 12:00

Slab-on-grade with concrete stem wall and under slab insulation

Publication Date

Tue, 01/01/2013 - 12:00

Patio Slabs, Porch Slabs, Walkways, and Driveways Slope Away from House

Guide describing how to correctly slope solid surfaces outside a home so rainwater flows away from the home.

Concrete Slab over Polyethylene

Publication Date

July, 2015

Video describing concrete slab over polyethylene barrier.

The basement slab is wrapped in a blanket of insulation including R-27 of closed-cell spray foam under the slab and R-22 ICF blocks wrapping the slab edges.

Building Enclosure: Foundation Overview

Right – The slab is coated with two coats of epoxy paint to minimize moisture transfer through the slab from the ground.

Slab-on-grade radon control techniques

Publication Date

Tue, 01/01/2013 - 12:00

Slab Happy, BSI-059

Author(s)

Lstiburek Joseph W

Organization(s)

Building Science Corporation,

BSC

Publication Date

April, 2012

How hard can it be to insulate a flat sheet of concrete? I mean you only have three choices – on the top, on the bottom, or on the edge. OK, you might have some combination of the three as well.

Technology Fact Sheet Slab Insulation: Improve Comfort and Save Energy in Homes with Slab-on-Grade Floors

Author(s)

Southface Energy Institute

Organization(s)

DOE

Publication Date

December, 2000

Brochure describing insulation approaches for homes with slab-on-grade floors.

Termite-Resistant Foundations and Walls

Guide describing techniques and measures for increasing the termite resistance of a home's foundations.

Slab-on-grade termite control techniques

Publication Date

Tue, 01/01/2013 - 12:00

Residential Buildings: Foundations

Author(s)

U.S. Department of Energy

Organization(s)

DOE

Publication Date

August, 2022

Website describing the U.S. Department of Energy's residential buildings program.

Right – A sump pump with a perforated sump pit was installed in the crawlspace slab to reduce water accumulation under the slab

Publication Date

Mon, 09/01/2014 - 12:00

Foundation Design Handbook

Author(s)

Carmody John,

Mosiman Garrett,

Handeen Daniel,

Huelman Patrick H,

Christian Jeffrey E

Organization(s)

Oak Ridge National Laboratory,

ORNL,

University of Minnesota

Publication Date

January, 2013

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.

Constructability of Elevating Concrete Slabs on Grade

Publication Date

April, 2019

Author(s)

American Concrete Institute

Organization(s)

ACI

Video from American Concrete Institute explaining the differences between foundation construction strategies and heights to mitigate damage from flooding.

Slab-on-grade with integral grade beam with exterior insulation

Publication Date

Tue, 01/01/2013 - 12:00

There is no polyethylene sheeting installed between the ground and the slab

Publication Date

Tue, 02/01/2011 - 12:00

Slab-on-grade with concrete masonry stem wall and exterior insulation

Publication Date

Tue, 01/01/2013 - 12:00

Turned down concrete slab - 1 inch rigid insulation

DWG

PDF

Decision-making process for foundation design

Publication Date

Tue, 01/01/2013 - 12:00

Concrete slab over polyethylene sheeting as capillary break

Publication Date

Thu, 02/01/2018 - 12:00

Innovation in Frost Protected Shallow Foundations

Author(s)

Green Home Institute

Organization(s)

Green Home Institute

Publication Date

January, 2019

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

Author(s)

Green Home Institute

Organization(s)

Green Home Institute

Publication Date

January, 2019

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.

Spray Foam Interior Insulation for Existing Foundation Walls

Guide describing how to insulate an existing foundation wall by adding spray foam insulation to the interior side of the wall.

BSC Information - Slab Edge Insulation for All Climates, Sheet 513

Author(s)

Building Science Corporation

Organization(s)

BSC

Publication Date

May, 2009

Information sheet about insulating slabs.

Turned down concrete slab - 3/4 inch rigid insulation

Author(s)

Benesch

Organization(s)

Cold Climate Housing Research Center,

CCHRC

Video describing radon precautions taken for a construction project in a high-risk radon area in Alaska.