When your project demands the ultimate in thermal resistance, our 4 inch rigid foam insulation provides the solution. Achieving R-values of R-20 or higher, these thick panels are perfect for high-performance Langley homes and "Passive House" designs. This depth of insulation is particularly effective for under-slab applications and foundation walls, where protecting against the cold earth is paramount. Western Insulation specializes in the precise installation of these high-volume panels, ensuring they are properly secured and sealed to provide a lifetime of energy efficiency. Experience the difference of premium insulation thickness in the variable Langley climate.