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Polar-R® Siding Underlayment

Film Faced EPS (4' x 8' 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. Combine those features with energy efficiency, moisture resistance, strength, durability and value, and you have found the perfect underlayment.

Polar-R® EPS was developed to meet all of these requirements and incorporates high performance EPS insulation with strong film facings, making it a durable underlayment for the application of new sidings. The Polar-R® design wraps your home in a continuous insulation envelope that reduces air infiltration and gives you a lifetime of energy savings.

Polar-R® EPS is available in 4’ x 8’ sheets and comes in a range of thicknesses: ½”, ¾”, 1 ½”, 2”, 3” and 4”.

Benefits of Polar-R® Siding Underlayment

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

Polar R Sheathing and Siding Underlayment ACH Foam Technologies

Installation Instructions for Polar-R® 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-R® 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-R® 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-R® reflective surface. (Consult the R-Value chart for more information.)

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