The Foam Sheathing Committee (FSC) serves as a manufacturing-driven organization focused on developing solutions to building code issues and promoting the proper technical use of foam sheathing to the construction industry.

Find more resources about Foam Sheathing on the Continuous Insulation website.

Foam Sheathing Committee (FSC) Members:

Atlas RoofingDowGAFHunter PanelsJohns ManvilleKingspan Insulation LLCOwens CorningRMAX



Foam Plastic Insulating Sheathing (FPIS) Products are offered in three types:

  • Expanded Polystyrene (EPS) - ASTM C578
  • Extruded Polystyrene (XPS) - ASTM C578
  • Polyisocyanurate (Polyiso) - ASTM C1289

FPIS products also come in many thicknesses to accommodate almost any end use.

FPIS Products shall be installed in accordance with:

Step 1

Place Insulation Boards

  • Ensure wall is square and true
  • Align boards with bottom edge of wall

  • Verify stud spacing, blocking, and bracing requirements with manufacturer
  • Provide framing or blocking for attachment of siding and trim at transitions
  • Seams should not be visible from interior unless allowed by manufacturer

Step 2

  • Typical detail for FPIS wall assembly attachment
  • Fasteners shall meet penetration requirements per manufacturer’s instructions and code requirements

(a) FPIS
(b) Fasteners
(c) Structural Sheathing (as required)
(d) Framing
(e) Cavity Insulation
(f) Interior wall finish

Step 3

Attach Insulation Boards

Space fasteners per manufacturer’s instructions

  • Around edges of panel
  • Through panels and into interior members

  • Drive nails flush and snug
  • Do not overdrive nails
  • Do not underdrive nails

Step 4

Trim Boards at Openings

  • Trim boards at all window and door openings
  • Cover all framing with FPIS
  • Fit joints tightly

Step 5

WRB and Flashing

  • Ensure that a code compliant water-resistive barrier (WRB) and required flashing is provided
  • If using FPIS as a WRB: 
    • Seal all joints and openings and penetrations per manufacturer’s installation instructions

  • At pipe and other small penetrations, seal gaps with silicone or expanding spray foam sealant
  • Seal joints and openings with joint tape per manufacturer’s instructions

  • Repair damaged areas per manufacturer’s instructions.