GreenGuard extruded polystyrene (XPS) insulation can be used with flat or pedestal pavers, ballast, or a vegetative system. Its 4-sided routed drainage channel board is for protected membrane roof assemblies that require 40 or 60 psi minimum compressive strength and drainage channels.
The insulation board has an R-value of 5 per inch and retains its insulating properties over time. Available as 2x8- and 4x8-foot boards in thicknesses from 0.5 to 4 inches with compressive strengths of 25, 40, and 60 psi.