Extruded polystyrene (XPS) Extended Flight at DFW Airport

When the time came to replace membranes in insulated and ballasted roofing assemblies on four terminal buildings at the Dallas/Fort Worth (DFW) International Airport, everything old was new again. The project team looked for insulation under the rock ballast already in-place and found perfectly re-usable extruded polystyrene (XPS) insulation made more than 17 years ago. After sending samples of this extruded polystyrene (XPS) insulation to a laboratory to verify a lack of moisture and the appropriate compressive strength and R-value (the material retained 90 percent of the latter), the hired roofing consultant designed the projects to reuse as much of the existing extruded polystyrene (XPS) insulation as possible—nearly 90 percent of the old material.

This efficient use of resources allowed the airport to save thousands of dollars that would have been spent taking the old material to a landfill and replacing it with all new insulation. Labor for getting the old insulation off the roof and the price of new materials (including transportation) would have otherwise added thousands of dollars to the project. There are also environmental benefits to being able to reuse the extruded polystyrene (XPS) . The strategy meant reusable material was not being sent to the landfill, and fossil fuel was not being consumed in manufacturing new insulation.