Raised and On-Grade Slab Edge Insulation

Detail ID
4.0403.1
Topic
Conditioned Subspaces
SubTopic
Slabs
Desired Outcome

Durable, pest-resistant, thermal break between the slab edge and outdoors

SF Single Family Site-Built Housing
MH Manufactured Housing
MF Multifamily Housing

Specifications

  • SF
  • MF
Specification Objective

Verify all bulk sources of moisture have been directed away from the slab (i.e., gutters, flashing, grading, drainage)

Wall sill plate and slab edge penetration air sealing is completed

No active pest intrusions exist

Ensure space can be safely insulated

  • SF
  • MF
Specification Objective

Select insulation that is rated for ground contact and is a class I vapor retarder

Durable insulation selected

  • SF
  • MF
Specification Objective

Select sealants that:

are compatible with their intended surfaces

allow for differential expansion and contraction between dissimilar materials

meet the requirements of the applicable fire safety code (e.g., thermal or ignition barriers)

are low volatile organic compound (VOC) sealants for use inside the pressure boundary that meet independent testing and verification protocols

Select safe and effective sealants

  • SF
  • MF
Specification Objective

Prepare slab edge to receive insulation and/or sealing materials per manufacturer specifications

Surface ready for insulation and sealant

  • SF
  • MF
Specification Objective

Excavate slab edge to prescribed depth and width for installation while avoiding undermining slab footing or damaging underground utilities or drainage

Protect excavation from weather until restored to original condition (e.g., density, drainage function)

Provide installation access and protect slab and utilities from damage

  • SF
  • MF
Specification Objective

Install insulation to prescribed R-value in contact with the slab edge, without voids, compressions, or misalignments and tight to any utilities penetrating the slab edge insulation

Continuous and contiguous thermal boundary

  • SF
  • MF
Specification Objective

Install continuous and permanent flashing to direct water away from the foundation and slab edge insulation

Direct bulk moisture away from slab insulation

  • SF
  • MF
Specification Objective

Cover exposed insulation with a durable, rigid, and pest-resistant material

Protect insulation from weather and impact

  • SF
  • MF
Specification Objective

Seal all slab edge penetrations using a compatible sealant

Stuff any gaps 1/4" or greater with copper or stainless steel mesh prior to sealant application

Airtight and pest-resistant slab edge

  • SF
  • MF
Specification Objective

Preserve existing termite treatment and inspection gaps as required by applicable codes

Prevent pest entry and maintain applicable warranties

  • SF
  • MF
Specification Objective

Restore excavated earth and grade to drain bulk moisture away from foundation

Preserve the drainage plane of the slab edge

  • SF
  • MF
Specification Objective

Post a dated receipt signed by the installer that minimally includes: Installed insulation type, coverage area, installed thickness, and installed R-value

Comply with 16 CFR 460.17 and document contract compliance

View Sub-Topic:
Slabs