Open-Cell Spray Foam Insulation Calculator

Open-cell spray foam can air seal complex cavities, but it is not a vapor-control shortcut in cold or mixed climates. Use this as early material planning only; confirm actual product datasheets and local assembly requirements.

Default material estimate

  • R-value per inch: R-3.7
  • Required thickness for R-20: 5.4 inches
  • Order area with 10% waste: 550 sq ft
  • Estimated material cost: $1,634

Material snapshot

  • Category: Spray foam
  • Form: Site-applied low-density foam
  • Typical use: Unvented rooflines and irregular cavities where air sealing is part of the insulation strategy.

R-value calculator · Wall assembly builder · Shed insulation calculator