Enerfoil by IKO is a rigid polyisocyanurate insulation sheathing with a foil facer laminated on the top and bottom side. 

Enerfoil is sheathing that:

• Provides high thermal resistance of R6 per inch (RS1 1.05 per 25 mm) for improved energy efficient performance of walls.
• Helps decrease the cost of construction.  Designers can reduce the overall footprint of their buildings, as a smaller thickness of Enerfoil achieves the same R-value (RS1) of other types of insulation.
• Is environmentally friendly.  No ozone-depleting HCFC’s are used in the manufacture of Enerfoil, making it and ideal “Green” product. Enerfoil’s Energy Star certification means that it clearly contributes to reducing energy consumption.
• Has a uniform thickness for consistently maintaining air space requirements in cavity wall application