ACH Foam Technologies' Tapered Foam Control Plus+ 600 EPS insulation was specified for the foundation for the green roof plaza deck for this Chicago condominium building on Lake Shore Drive.

We all know what the typical green roofs look like, but what's underneath it, the engineered aspects, are critical to a planted roof. Take the new fourth-story plaza green roof deck built over the parking garage of the condominium building at1000 Lake Shore Drive in Chicago. The architect/engineer, Wiss, Janey, Elstner and Associates, specified installation of 5,000 sq. ft. of EPS insulation (Foam Control Plus+ tapered 600 EPS) over rubberized asphalt waterproofing. EPS, or expanded polystyrene, is a rigid plastic made from petrochemicals in the form of "preexpanded polystyrene beads." EPS is used for disposable trays, bowls, plates and those to-go white plastic hinged-lid containers, plus for shipping "peanuts." For building insulation purposes, EPS comes in rigid sheets 2x8 or 4x8 known as "bead-boards."

For this Chicago roof, the EPS boards provided three primary functions: insulate the garage roof, provide compressive strength and create a slope for drainage. According to the building contractor for this project, Eric Dexter of Berglund Construction, the use of tapered extruded polystyrene (XPS) on an earlier project and similar application was frustrating, because the installers had to handle so many pieces in multiple layers. The EPS large 4x8 sheets from ACH Foam Technologies, he notes, sped up the construction significantly."