Products > Therma > Therma TW56 > Overview Therma TW56 Insulated dry-lining plasterboard for mechanical fixing Kingspan Therma TW56 Properties Download PDF Thermal conductivity 0.022 W/m.K Front Facing 12.5mm plasterboard 0.19 W/m.K (plasterboard component) Core High performance rigid thermoset polyisocyanurate (PIR) insulant manufactured with a blowing agent that has zero Ozone Depletion Potential (ODP) and low Global Warming Potential (GWP). Reverse Facing Composite foil Board size 1.2 x 2.4 m