XPS Foam Board Insulation Calculator

XPS foam board is common around foundations and slabs, but it should be weighed against lower-impact rigid options. Use this as early material planning only; confirm actual product datasheets and local assembly requirements.

Default material estimate

  • R-value per inch: R-5
  • Required thickness for R-20: 4 inches
  • Order area with 10% waste: 550 sq ft
  • Estimated material cost: $1,430

Material snapshot

  • Category: Rigid board
  • Form: Extruded polystyrene rigid foam
  • Typical use: Foundation walls, slabs, and some exterior wall retrofits.

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