Kingspan Kooltherm K106 Cavity Board is a performance rigid thermoset fibre-free phenolic insulation core bonded to a water-tight, vapour-open polypropylene fleece and to a inner facing of a low emissivity composite foil. It is designed to limit thermal bridging and uncontrolled air–leakage via junctions in cavity wall constructions. Kingspan Kooltherm K106 Cavity Board is unlikely to become ignited within the cavity. If fire does penetrate into an unventilated cavity, the amount of air present will be insufficient to support combustion, and flame spread will be minimal.