4.1403.1 Slab-Edge Foundations and Above-Grade Concrete Decks— Raised and On-Grade

Basements and Crawl Spaces
Slab Foundations
For supporting material, see Building America Solution Center.
Desired Outcome: 
Thermal break between the slab edge and outdoors and ground

An exterior and interior inspection will be conducted for water damage, drainage plane failures, grading issues, and breaches unrelated to the specified air sealing and insulating work

Repairs necessary to stabilize work areas and protect or preserve integrity of energy improvement will be completed before subject work begins

Site will be evaluated to determine potential for excavation

Identify all underground utilities entering the building in the work area

Repair moisture and structure-related issues

Provide a stable slab and related assemblies to ensure the durability of the work

Ensure that any underground utility services are located and protected from damage

Air sealing

Air sealing between conditioned space and unconditioned space will be completed before insulating

Ensure airtight floor assembly


Excavation will be done to expose the slab edge to the required depth

Caution will be exercised to avoid undermining slab footing and to avoid damage of underground utilities

Excavations will be weather protected (moisture and frost) and will be restored to original condition (density, drainage function) as quickly as possible

Provide below-grade installation access

Protect slab and utilities from damage

Clean and prepare surfaces

Slab edge will be prepared for material installation to meet manufacturer specifications

Ensure a durable installation

Top and bottom flashing

Flashing will be continuous and permanently secured

Preserve the drainage plane of the wall


Insulation will be installed to prescribed R-value

Insulation will be installed in contact with the slab edge, without voids, compressions, or misalignments

Insulation will be run tight to any utilities penetrating the slab edge insulation

Provide effective R-value

Protective cover

Exposed insulation will be covered with a durable, rigid material Rigid material Drywall, oriented strand board, duct board, cardboard, or any other stiff product that may support the load of insulation while serving as a durable air barrier

Protect insulation from weather and impact


Existing termite treatment and inspection gaps will be preserved, and termite control measures consistent with local code requirements will be implemented, as required

Prevent pest entry and maintain applicable warranties

Back fill

Restore excavated earth and grade to preserve drainage plane

Preserve the drainage plane of the slab edge

Property manager education

A dated receipt signed by the installer will be provided that includes:

  • Coverage area
  • Thickness
  • R-value
  • Document job completion to contract specifications

    Comply with 16 CFR 460.17

    Confirm amount of insulation installed