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Polar Fold® Siding Underlayment

Film Faced EPS (4' x 50' Fan Fold Sheets)

All beautiful siding projects begin with a solid foundation so you will need a material that provides a flat and level surface for new siding. Polar Fold® Siding Underlayment combines high performance EPS with strong film facings, making it a durable underlayment for the application of new sidings. The Polar Fold® design wraps your home in a continuous insulation envelope that reduces air infiltration and gives you a lifetime of energy savings.

Polar Fold® expanded polystyrene (EPS) is available in 4’ x 50’ sheets and comes in 3/8" and 1/2" thicknesses.

Benefits of Polar Fold® Siding Underlayment

  • Superior Moisture Resistance
  • Continuous Level Surface
  • Energy Efficient
  • Less Cost Per R-Value
  • Durable and Strong
  • Easy to Handle and Install
    • Fan Fold® reduces product size for easy jobsite handling and storage
  • Termite Resistant
  • Environmentally Friendly
    • Polar-R® contains no CFCs, HFCs, HCFCs or formaldehyde and is available with a 50-year R-Value warranty.

Installation Instructions for Polar Fold® Siding Underlayment

  • The substrate should be flat, dry and free of any foreign materials that would damage the insulation board.
  • Beginning installation indicates that the installer has accepted the condition of the existing substrate.
  • Install Polar Fold® EPS directly over existing substrate using galvanized or aluminum roofing nails. Remove any damaged siding and install directly over framing members if necessary. Avoid over driving fasteners, because this will compress the insulation and create a wavy appearance of the new siding exterior.
  • The installer should be careful when installing under new siding materials. The board must lay flat and be adequately fastened.
  • Install new siding directly over the Polar Fold® per the siding manufacturer’s recommendations.
  • A higher R-Value can be achieved by using ½” furring strips between the existing substrate and the Polar Fold® reflective surface. (Consult the R-Value chart for more information.)
Polar Fold® contains no CFCs, HFCs, HCFCs or formaldehyde and is available with a 50-year R-Value warranty.

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