Carlisle's high-performance ChannelDry insulation is composed of lightweight, closed-cell expanded polystyrene. ChannelDry has excellent dimensional stability, compressive strength, and water-resistant properties. ChannelDry is designed to be mechanically fastened directly to concrete decks. The use of ChannelDry in conjunction with one-way and two-way relief vents allows the installation of the roof system to begin upon structural cure of concrete.