$52.99 Shop Rmax Polyisocyanurate Foam Board Insulation (Common: 1-in x 4-ft x 8-ft; Actual: 1-in x 4 
R-Tech (Common: 2-in x 2-ft x 8-ft; Actual: 2-in x 2-ft x 8-ft) R7.7 Faced Polystyrene Garage 
Johns Manvilleâs Polyiso Insulation Recommended for Retrofits | SBC Magazine
