4.1005.7 Attic Floor—Preparation and Installation of Spray Polyurethane Foam (SPF)

Attic Floors
Desired Outcome: 
Consistent, thermal boundary Thermal boundary The separation between the interior and exterior environments of a building that slows heat flow and air barrier Air barrier The separation between the interior and exterior environments of a building that slows air flow to the point that no smoke movement is visible at 50 pascals of pressure difference across the boundary between conditioned and unconditioned space controls the heat flow and air leakage

Subfloor or drywall will be removed to access cavities as necessary (e.g., beneath attic knee walls)

All electrical junctions will be flagged to be seen above the level of the insulation

Open electrical junction boxes will have covers installed

Access the workspace

Provide location of electrical junctions for future servicing

Prevent an electrical hazard


Insulation will be installed to prescribed R-value

SPF SPF Spray polyurethane foam will be applied to desired thickness onto attic floor to ceiling material below between attic floor joists using pass thickness maximum as indicated by manufacturer

Insulate to prescribed R-value


Spray foam should never be installed over light fixtures regardless of if fixture is rated for IC IC Insulation contact or not. Nor between a heat-generating appliance and a dam, unless material is rated for contact with heat-generating sources.

Prevent a fire hazard

Onsite documentation

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

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

    Confirm amount of insulation installed

    Comply with 16 CFR 460.17

    Occupant education

    Documentation of material and R-value will be provided to occupant

    Provide occupant with documentation of installation