Norandex Fanfold is an extruded polystyrene (XPS) foam insulation board for easy installation over existing exterior surfaces.  It is used as a rigid foam underlayment for new siding materials.  The Norandex Fanfold features a straight cut hinge, allowing the cladding to lie flat. All of the fanfold products contain no VOC's, are formaldehyde-free, are not a known food source for mold and insects, and are recyclable. 

Norandex Fanfold is offered in 3 different sizes: 3/8", 1/4", and 1/2"

3/8” Fanfold and 1/4" Fanfold

  • Nominal 3/8” thick extruded polystyrene board for the 3/8" Fanfold
  • Nominal 1/4" thick extruded polystyrene board for the 1/4" Fanfold
  • Produced in continuous 4’ x 48’ fanfold sections with 24” crimped-seam spacing
  • Sealing effectiveness and a smooth level surface for new siding
  • Meets ASTM C578 Type IV – Standard Specification for Rigid Cellular Polystyrene Thermal Insulation
  • Features a straight cut hinge
  • Features flat seams
  • Covers wall studs and cavity, enhancing thermal efficiency and moisture management

1/2” Fanfold

  • 1/2” insulation can be used with vinyl, steel, or aluminum siding
  • Produced in continuous 24’ x 4’ fanfold sections
  • 1/2” Extruded Polystyrene Foam Insulation is an air infiltration, insulation performance, vapor permeability and moisture resistance.
  • Can be used in residing applications as well as new frame wall constructions behind siding
  • Alternative water resistive barrier as prescribed in Section 1404.2 of the IBC, Section 703.2 of the IRC and Section 1402.1 UBC when installed on exterior walls.
  • Sealing effectiveness and a smooth level surface for new siding
  • Helps homes stay warmer in winter and cooler in summer, free from air leaks that can cause up to 40 percent of normal heat loss or gain