4.1301.9 Open Floors Over Unconditioned Space and Cantilevered Floors, Floors Over Garages, Floors Over Unconditioned Crawl Spaces—Spray Polyurethan

Accessible Floors
Desired Outcome: 
Floors over unconditioned spaces (e.g., basements, garages) insulated and sealed

All floor areas will be open and accessible for SPF SPF Spray polyurethane foam application

Cracks, gaps, and holes will be covered or sealed per manufacturer guidelines with appropriate material

Insulation dams or end blockers will be installed where needed

All surfaces where SPF SPF Spray polyurethane foam is applied will be clean, dry, and free of contamination and degradation

Substrate surfaces will be wiped, blown, or vacuumed to be free of excessive dust and dirt

Grease and oil will be removed using appropriate cleaners or solvents

Moisture content of all wood substrate materials will be checked to ensure it is below 20%

Prepare all substrate surfaces for the application of SPF SPF Spray polyurethane foam


Insulation will be installed to prescribed R-value according to manufacturer specifications

SPF SPF Spray polyurethane foam will be applied to desired thickness, using pass thickness maximum as indicated by manufacturer, onto subfloor between floor joists and all rim/band joists

When desired, underside of joists will be covered with SPF SPF Spray polyurethane foam to provide layer of continuous insulation

Insulate and seal floors

Fire protection

SPF SPF Spray polyurethane foam will be separated from the interior occupied space of the building with a 15-minute thermal barrier (typically ½" or thicker gypsum wallboard or approved ignition barrier Ignition barrier Any layer of material that protects another from catching fire due to heat or spark coating)

Check local codes for fire protection requirements

Provide necessary fire protection for combustible SPF SPF Spray polyurethane foam insulation

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